JP2013258828A - Charging system and charging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform fast charging of a power receiving device used repeatedly from a low capacity small scale power supply device.SOLUTION: A power supply device and a power receiving device include, respectively, power storage modules B1, B2 each consisting of a high energy density power storage element, power storage modules C1, C2 each consisting of a high output density power storage element, and first and second switches D1, D2 capable of switching the charge/discharge path for the power storage modules B1, B2, C1, C2. The first and second switches D1, D2 are subjected to switching control depending on the charging state.

Description

  The present invention relates to a charging system and method for charging a power receiving device by supplying power from a power supply device, and more particularly to a charging system and method suitable for rapid charging.

  Unlike stationary electronic devices that are used with a power plug connected to a commercial AC power supply, mobile electronic devices such as automated guided vehicles and electric carts, and mobile electronic devices such as mobile phones and laptop computers A storage battery is used as a power supply device. As specific storage batteries, lead storage batteries, nickel cadmium batteries, nickel metal hydride batteries, and lithium ion batteries are candidates. In particular, lithium ion batteries do not contain harmful metals such as lead and cadmium, are light in weight per volume, and have a large discharge capacity, so their use is increasing.

  In recent years, the development of an electric vehicle which is a kind of the above-described moving body has become active. The electric vehicle is equipped with a power storage module 10 including a plurality of storage battery cells as a power source. In order to charge each cell discharged by use so that it can be used again, a charging station provided with a power supply device capable of charging the power storage module 10 in the same manner as a gasoline station that supplies gasoline to a general gasoline vehicle. is necessary.

  Such a power supply device for an electric vehicle converts, for example, a 100V or 200V household AC current or a 6000V high-voltage AC current into a voltage of the power storage module 10 to rectify the rectified output, and controls the amount of current. The power storage module 10 is supplied with power. The voltage of the power storage module 10 is determined by the type of cells used and the number of cells connected in series, and is designed to be, for example, about 50 to 100V.

Here, the electric vehicle needs to be equipped with a power storage module 10 having a power supply capacity of several hundred kW necessary for the driving motor and a discharge capacity capable of guaranteeing a traveling distance of several hundred km by one charge. is there. For this application, the power storage module 10 using a light-weight and high-capacity lithium ion battery is considered to be optimal at present.
This power storage module includes a power storage unit in which a plurality of cells are connected in series, and can be discharged at a total voltage of the cell voltages connected in series. Further, if each cell included in the power storage unit is replaced with a power storage unit including a single cell or a plurality of cells connected in parallel, the capacity can be further increased and used for a long time.

  As a storage battery charging method, CCCV (constant current constant voltage) charging is known. In this CCCV charging, the storage battery is first charged with the constant current I, and when it is detected that the voltage of the storage battery has reached the target maximum value V, the constant current charging is stopped. It should be noted that the storage battery has an internal resistance r. Therefore, when the constant current charging is stopped, the voltage E of the storage battery includes a voltage drop Ir (hereinafter referred to as “Ir voltage drop”) due to the internal resistance r. = The battery is charged only at a voltage of V-Ir. That is, the larger the current I, the greater the difference between the actually charged voltage E and the target charging upper limit voltage V.

Therefore, in CCCV charging, after the constant current charging is completed, the current is gradually decreased from I to I ′ close to 0 to reduce the Ir voltage drop, and charging is performed at the constant voltage V, which is close to full charging. E ′ = V−I′r is reached to complete the constant voltage charging.
According to the above-described CCCV charging, even a storage battery having a high internal resistance r can be charged almost fully charged, but has a drawback that it takes a long time to charge. For example, when CCCV charging is performed on a 550 mAh lithium ion battery used for a mobile phone, it takes 2 hours in total, which is 1 hour for constant current charging and 1 hour for constant voltage charging. Furthermore, the charging time increases as the battery capacity increases.

Similarly, in order to increase the distance that an electric vehicle can travel with one charge, it can be realized by increasing the capacity of the storage battery to be mounted, but there is a problem that the time required for charging becomes longer accordingly. It was. The reason why the required charging time becomes longer depending on the size of the battery capacity is that the maximum value of the charging current is limited by the rate of the electrochemical reaction.
In other words, a storage battery that converts electrical energy into chemical energy by electrochemical reaction and stores it has a maximum charging current limited by the rate of the electrochemical reaction. Cannot be added. Accordingly, it is inevitable that the time required for charging becomes longer depending on the size of the battery capacity.

  On the other hand, since the capacitor stores electric energy as electrostatic energy by polarization, no electrochemical reaction is required. Therefore, the capacitor without the upper limit of the charging current determined by the rate of the electrochemical reaction described above can be rapidly charged / discharged with a current about 100 times that of the storage battery. Therefore, if a capacitor is used for the power storage module on the power receiving device side, rapid charging that cannot be achieved with a storage battery is possible.

  In such a background art, as a method for charging a mobile power receiving device in a short time, an electric double layer capacitor, or a storage battery as an auxiliary energy source in parallel to the power storage module on the power receiving device side, is provided. A method of using a connected device has been proposed (see Patent Document 1). Moreover, in the power receiving device in which the capacitor and the storage battery are connected in parallel, a method of charging from the capacitor when the output of the storage battery decreases has also been proposed (see Patent Document 2).

  On the other hand, in a power supply apparatus that uses a commercial AC power supply of 100 to 200 V, in order to enable rapid discharge, a large-capacity power receiving facility and a large-sized power supply circuit are required, and installation is difficult. In particular, in the rapid charging for shortening the required charging time, the power demand is about several hundred kVA, so that it is necessary to increase the power receiving facility to one having a large capacity. In other words, it is impossible to install a charging station at an arbitrary location where only the low-voltage power line is laid.

  Therefore, as a method for rapid discharge from the power supply device under such circumstances, the power storage module is provided by a power supply device using a small power circuit and a power storage module in which a required number of storage battery cells are connected in parallel. A method has been proposed in which charging with a small current and discharging with a large current are compatible, and a power storage device-side storage battery is rapidly charged (see Patent Document 3).

  Proposed is a rapid power supply unit consisting of a low-speed charging unit that charges a storage battery or a large-capacitance capacitor from an AC power source, and a rapid charging unit that rapidly charges the storage battery or capacitor of the load by the large-current discharge of the storage battery or the large-capacitance capacitor (See Patent Document 4).

Japanese Patent Laid-Open No. 7-163016 JP 2008-137451 A JP-A-6-253461 JP 2011-36117 A

With the charging systems and methods described in Patent Literatures 1 and 2, it is considered that the power receiving device can cope with rapid charging. However, in order to make the power supply device compatible with rapid charging, it is necessary to increase the power supply capacity per unit time by increasing the capacity of the power supply device so that it is half proportional to the shortened charge / discharge time. .
Further, when a capacitor capable of rapid charging / discharging is used on the power receiving device side, the voltage drop due to the self-discharge of the capacitor is faster than that of the storage batteries connected in parallel inside the power receiving device. Therefore, when the power supply device after charging is in a non-use state in which no power is consumed for a long time, for example, several tens of days, the capacitor self-discharges and becomes nearly empty. When restarting according to the electric power demand for operating the mobile body etc. which mounts the power supply device, an excessive inrush current may flow from the storage battery connected in parallel to the capacitor near the sky.

On the other hand, in the charging systems and methods described in Patent Documents 3 and 4, it is considered that the power feeding device side can cope with rapid discharge, but the storage battery on the power receiving device side is considered to be inferior in rapid chargeability.
Therefore, the present invention has been made in view of the above-described points, and is a power supply device that relies on a small-scale, low-capacity external power supply, or a power supply device installed at any location where only a low-voltage power line is laid. Therefore, an object of the present invention is to provide a charging system and method capable of rapidly charging a power receiving apparatus.

  According to the first aspect of the present invention, the storage battery of the power receiving device is charged from the power feeding terminal of the power feeding device via the power receiving terminal of the power receiving device with the power charged in the storage battery of the power feeding device by the supply from the external power source. In the charging system, the power supply device includes a first power storage module configured with a high energy density power storage element having a large chargeable / dischargeable capacity, a high power density power storage element having a large chargeable / dischargeable current per unit time, or a plurality of power storage devices. A second power storage module having a power storage unit in which a plurality of power storage units composed of the high power density power storage elements connected in parallel are connected in series, and the first power storage module connected to an external power source and disconnected from the second power storage module It is possible to switch between the first connection state and the second connection state in which the first power storage module is connected to the second power storage module and disconnected from the external power source. A high-power density storage element having a large current that can be charged / discharged per unit time, or a plurality of parallel switches in the power receiving device. A third power storage module having a power storage unit formed by connecting a plurality of power storage units configured by the connected high power density power storage elements in series, and a fourth power storage unit configured by a high energy density power storage element having a large chargeable / dischargeable capacity. A power storage module; a third connection state in which the fourth power storage module is connected to the load and disconnected from the third power storage module; and a fourth connection state in which the fourth power storage module is connected to the third power storage module and disconnected from the load. A second switch capable of switching between and, and a control unit capable of control including the second switch.

  According to a second aspect of the present invention, in the charging system according to the first aspect, the third power storage module includes a plurality of bypass switches that are connected in parallel for each power storage unit and the bypass path is conducted when the switch is turned on. And a bypass control unit that controls the bypass switch based on a voltage value of each power storage unit.

According to a third aspect of the present invention, in the charging system according to the second aspect, the third power storage module includes a charge switch that is inserted in series in the input / output path of the power storage unit and turns the input / output path on / off. The bypass control unit further has a function of controlling the charge switch.
According to a fourth aspect of the present invention, in the charging system according to any one of the first to third aspects, the first switch includes the second connection state in addition to the first connection state and the second connection state. A fifth connection state in which a power storage module is connected to the external power source and disconnected from the first power storage module, and a state in which at least any two points of the contact point related to the first switch are made conductive are selectable, In addition to the third connection state and the fourth connection state, the second switch connects the third power storage module to the load and disconnects the fourth power storage module from the sixth connection state, It is possible to select a state in which at least any two points of the contact point related to the second switch are made conductive.

  According to a fifth aspect of the present invention, in the charging system according to any one of the first to fourth aspects, the power feeding path is inserted into a power feeding path between the second power storage module and the power feeding terminal. A power switch, and the control unit turns off the power switch when the first switch is in the second connection state or the fourth connection state, and the first switch is the second connection. The power supply switch is turned on when neither the state nor the fourth connection state is present.

  The invention according to claim 6 is the charging system according to claim 4, wherein the control unit includes the second connection state, the fifth connection state, the fourth connection state, and the sixth connection state. The power switch is turned off at any of the above, and the power switch is turned off when the second connection state, the fifth connection state, the fourth connection state, or the sixth connection state is not any of It is characterized by being turned on.

The invention according to claim 7 is the charging system according to any one of claims 1 to 6, wherein the external power source includes a solar cell or an AC power source.
According to an eighth aspect of the present invention, in the charging system according to any one of the first to seventh aspects, the high-power density storage element is constituted by a lithium ion capacitor or an electric double layer capacitor.

According to a ninth aspect of the present invention, in the charging system according to any one of the first to eighth aspects, the power receiving device is included in a moving body and supplies driving power to the moving body.
The invention according to claim 10 is the charging system according to claims 1 to 9,
The total amount of power when the power storage unit included in the second power storage module is fully charged is greater than the total amount of power when the power storage unit included in the third power storage module is fully charged.

The invention according to claim 11 is a charging method using the charging system according to any one of claims 1 to 10, wherein the third power storage module is charged by the power stored in the second power storage module. One charging step is included.
The invention according to claim 12 is a charging method using the charging system according to any one of claims 2 to 10, wherein the third power storage module is charged by the power stored in the second power storage module. In one charging step, the first step of turning off all bypass switches and charging the power storage unit until at least one voltage value of the plurality of power storage units becomes equal to or higher than the charging target voltage; A second step of turning on a bypass switch of a bypass circuit corresponding to the reached power storage unit to bypass the current flowing in the power storage unit to the bypass circuit; and a power storage unit in which the current is bypassed by the second step When the voltage value of the battery becomes equal to or lower than the charging resumption voltage, the bypass switch corresponding to the power storage unit is turned OFF to bypass the bypass. A third step of supplying a current to the power storage units, characterized in that it comprises a.

According to a thirteenth aspect of the present invention, in the charging method of the twelfth aspect, after a first predetermined time has elapsed since the voltage value of at least one power storage unit has reached or exceeded the charge target voltage, A fourth step is included, which includes turning off the route to interrupt or complete the charging.
The invention according to claim 14 is the charging method according to claim 12 or 13, wherein in the first charging step, the second step and the third step are repeatedly executed, and in the second step, a charging target The bypass switch corresponding to the power storage unit that has passed the second predetermined time after reaching the voltage is turned on, and the current flowing through the power storage unit is diverted to the bypass circuit.

According to a fifteenth aspect of the present invention, in the charging method according to any one of the eleventh to fourteenth aspects, the first power storage module is charged with the power feeding terminal and the power receiving terminal not electrically connected. A second charging step of charging the second power storage module with the generated electric power.
According to a sixteenth aspect of the present invention, in the charging method according to any one of the eleventh to fifteenth aspects, the third power storage module is charged with the power feeding terminal and the power receiving terminal not electrically connected. And a third charging step of charging the fourth power storage module with the generated electric power.

The invention according to claim 17 is the charging method according to any one of claims 11 to 16, further comprising a fourth charging step of charging the first power storage module with electric power of the external power source.
According to an eighteenth aspect of the present invention, in the charging method according to any one of the eleventh to seventeenth aspects, a fourth charging step of charging the first power storage module with electric power of the external power supply is performed simultaneously with the first charging step. It is characterized by performing.

  According to a nineteenth aspect of the present invention, in the charging method according to any one of the eleventh to eighteenth aspects, the power supply terminal and the power receiving terminal are not electrically connected, and the first power is supplied from the external power source. 2 The 5th charge process which charges an electrical storage module is included, It is characterized by the above-mentioned.

  According to the present invention, rapid charging of a power receiving device that is repeatedly used from a power feeding device that depends on a low-capacity, small-scale external power supply or a power feeding device that is installed at any location where only a low-voltage power line is laid. Can be provided.

It is a schematic circuit diagram which shows the basic form of the charging system which concerns on embodiment of this invention. It is a schematic circuit diagram which shows the development of the charging system which concerns on embodiment of this invention. It is a schematic circuit diagram which shows the connection state of the 1st and 2 switches of the charging system which concerns on embodiment of this invention, (a) 1st connection state, (b) 2nd connection state, (c) 3rd connection state, (D) a fourth connection state, (e) a fifth connection state, and (f) a sixth connection state. It is a schematic circuit diagram which shows each charge state of the charging system which concerns on embodiment of this invention, (a) 1st charge process, (b) 2nd charge process, (c) 3rd charge process, (d) 4th A charging step, (e) simultaneous execution of the first charging step and the fourth charging step, and (f) a fifth charging step. It is a schematic circuit diagram which shows an example of the electrical storage module used for the charging system of this invention. It is a flowchart which shows the charge method which concerns on 1st Embodiment of this invention. It is a flowchart which shows the charging method which concerns on 2nd Embodiment of this invention. It is the figure which showed the relationship between the voltage of an electrical storage unit and time by the charging method (FIG. 7) which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the charging method which concerns on 3rd Embodiment of this invention. It is the figure which showed the relationship between the voltage of an electrical storage unit and time by the charging method (FIG. 9) which concerns on 3rd Embodiment of this invention. It is a flowchart which shows the charging method which concerns on 4th Embodiment of this invention. It is the figure which showed the relationship between the voltage of an electrical storage unit and time by the charging method (FIG. 11) which concerns on 4th Embodiment of this invention.

(Charging system)
FIG. 1 is a schematic circuit diagram showing a basic form of a charging system according to an embodiment of the present invention. A charging system 100 illustrated in FIG. 1 is electrically connected to an external power source S such as a commercial power source, a power feeding device 50 that receives power supplied from the external power source S, and has power supply capability to the power receiving device 60, and the power feeding device 50. And a power receiving device 60 that receives a charging service as appropriate. The first to fifth charging steps shown in FIGS. 1 and 2 will be described in detail later along FIG.

  In addition, power supply terminals A1 and A1 ′ (hereinafter also simply referred to as power supply terminal A1) disposed in the power supply apparatus 50 and power reception terminals A2 and A2 ′ (hereinafter also simply referred to as power supply terminal A2) disposed in the power reception apparatus 60. And the power receiving device 60 receives a charging service from the power feeding device 50. Then, when the power receiving device 60 reaches a fully charged state or a practically charged state, the power receiving device 60 is separated from the power feeding device 50 by separating the power feeding terminal A1 and the power receiving terminal A2, so that the original carrying function and the like are performed. It becomes possible to work.

(Power supply device)
The power supply device 50 is a device that waits after receiving a supply of power from the external power source S to prepare a power supply system that makes the power reception device 60 fully charged in a short time as much as possible or in a practically charged state. In addition, the power receiving device 60 that receives the charging service is assumed to be a rechargeable mobile body such as an electric vehicle, a local transportation vehicle, and an electric cart. The power supply device 50 for providing an appropriate charging service to the rechargeable mobile body is assumed to be a charging station or a charging station in place of a conventional gasoline station for a gasoline vehicle.

The power supply device 50 can firstly fully charge a large number of power receiving devices 60 in as short a time as possible, and secondly, the power supply device 50 can supply power from a small external power source S. There is a strong demand for the two points of being able to operate upon receipt. By satisfying these requests. This leads to improvement in convenience and operating rate of facilities related to the charging systems 100 and 101.
The power supply device 50 includes a first power storage module B1, a second power storage module C1, a first switch D1, a power supply switch D3, a control unit 1, and power supply terminals A and A ′. 1st electrical storage module B1 is comprised with the high energy density electrical storage element with a large capacity | capacitance which can be charged / discharged. The 2nd electrical storage module C1 is comprised with the high output density electrical storage element with the big electric current which can be charged / discharged per unit time.

  The first switch D1 has a first connection state in which the first power storage module B1 is connected to the external power source S and disconnected from the second power storage module C1, and the first power storage module B1 is connected to the second power storage module C1 and the external power source S Is a switch that can be switched to the disconnected second connection state. The power supply switch D3 is a switch that is inserted in a power supply path between the second power storage module C1 and the power supply terminal A1, and turns the power supply path on and off.

  The control unit 1 can perform integrated control including the first switch D1 based on a control pattern determined by communication with the control unit 2 disposed on the power receiving device 60 side. A storage medium or the like storing a program to be executed and communication means are provided. When the power feeding terminals A and A ′ are electrically connected to the power receiving terminals B and B ′ arranged on the power receiving device 60 side, the control unit 1 controls the control unit 2 arranged on the power receiving device 60 side and information on charging. Perform communication as appropriate. In addition, the control unit 1 may include a unit that boosts the output voltage of the first power storage module B1, for example, a DC-DC converter, as necessary.

(Power receiving device)
The power receiving device 60 includes a third power storage module C2, a fourth power storage module B2, a second switch D2, a control unit 2, and power receiving terminals A2 and A2 ′. The 3rd electrical storage module C2 is comprised with the high output density electrical storage element. 4th electrical storage module B2 is comprised with the high energy density electrical storage element. The second switch D2 connects the fourth power storage module B2 to the load L and disconnects it from the third power storage module C2, and connects the fourth power storage module B2 to the third power storage module C2 and disconnects from the load L. It is a switch that can be switched to the fourth connection state.

  The control unit 2 can perform comprehensive control including the second switch D2 based on a control pattern determined by communication with the control unit 1 disposed in the power supply device 50, and executes a computer (not shown) and the computer. A storage medium storing a program to be executed and communication means. When the power receiving terminals A2 and A2 ′ are electrically connected to the power feeding terminals A1 and A1 ′ arranged on the power feeding device 50 side, the control unit 2 controls the control unit 1 arranged on the power feeding device 50 side and information on charging. Perform communication as appropriate. In addition, the control unit 2 may include a unit that boosts the output voltage of the third power storage module C2, for example, a DC-DC converter, as necessary.

  FIG. 2 is a schematic circuit diagram showing a developed form of the charging system according to the embodiment of the present invention. The difference between the charging system 101 shown in FIG. 2 and the charging system 100 shown in FIG. 1 is that the first switch D1, the second switch D2, the control unit 1 and the control unit 2 (hereinafter, both are collectively referred to as the control unit 1). Are also replaced by the first switch D10, the second switch D20, the control unit 21 and the control unit 22 (hereinafter, both are collectively referred to as the control unit 21).

  In addition to the first connection state and the second connection state described above, the first switch D10 includes a fifth connection state in which the second power storage module C1 is connected to the external power source S and disconnected from the first power storage module B1. It is possible to select a state in which at least any two points of the contact point related to the first switch D1 are made conductive. In addition to the third connection state and the fourth connection state, the second switch D20 includes a sixth connection state in which the third power storage module C2 is connected to the load L and is disconnected from the fourth power storage module B2, and a second connection state. It is possible to select a state in which at least any two points of the contacts related to the switch D20 are made conductive.

FIG. 3 is a schematic circuit diagram illustrating a connection state of the first and second switches of the charging system according to the embodiment of the present invention, where (a) a first connection state, (b) a second connection state, and (c) a first connection state. Three connection states, (d) a fourth connection state, (e) a fifth connection state, and (f) a sixth connection state.
The first connection state shown in FIG. 3A is a state in which the first switch D1 connects the first power storage module B1 to the external power source S and is disconnected from the second power storage module C1.
The second connection state shown in FIG. 3B is a state in which the first switch D1 connects the first power storage module B1 to the second power storage module C1 and is disconnected from the external power source S. At this time, the power supply switch D3 is OFF.
The third connection state shown in FIG. 3C is a state in which the second switch D2 connects the fourth power storage module B2 to the load L and is disconnected from the third power storage module C2.

The fourth connection state shown in FIG. 3D is a state in which the second switch D2 connects the fourth power storage module B2 to the third power storage module C and disconnects it from the load L. At this time, the power supply switch D3 is OFF. In order to prevent an excessive inrush current, when the voltage of the third power storage module is lower than a predetermined value and the voltage of the fourth power storage module is higher than a predetermined value, the fourth connection state is not set. It is preferable to control.
The fifth connection state shown in FIG. 3E is a state in which the first switch D10 connects the second power storage module C1 to the external power source S and is disconnected from the first power storage module B1. At this time, the power supply switch D3 is OFF.
The sixth connection state shown in FIG. 3F is a state where the second switch D20 connects the third power storage module C2 to the load L and disconnects it from the fourth power storage module B2. At this time, the power supply switch D3 is OFF.

  The control units 1 and 21 are connected to the first and second switches D1, D10, D2, and D20 based on the control pattern determined by communication with the control units 2 and 22 disposed on the power receiving devices 60 and 61 side. Integrated control including the power feeding switch D3 is possible. Integrated control based on the control pattern is realized by a computer executing a program stored in a storage medium (not shown). The control units 1 and 2 turn off the power feeding switch D3 when the first and second switches D1 and D2 are either in the second connection state or the fourth connection state. When the first switch D1 is neither the second connection state nor the fourth connection state, the power supply switch D3 is turned on. In addition, the control units 21 and 22 are power supply switches when the first and second switches D10 and D20 are in any of the second connection state, the fifth connection state, the fourth connection state, and the sixth connection state. Turn off D3. And the control parts 21 and 22 are power feeding switches when the first and second switches D10 and D20 are not any of the second connection state, the fifth connection state, the fourth connection state, and the sixth connection state. Turn on.

  FIG. 4 is a schematic circuit diagram showing each charging state of the charging system according to the embodiment of the present invention, where (a) a first charging step, (b) a second charging step, (c) a third charging step, ( d) a fourth charging step, (e) a simultaneous execution of the first charging step and the fourth charging step, and (f) a fifth charging step. The first to fifth charging steps are as shown in FIGS. In the following description, the capacity of the first and fourth power storage modules B1 and B2 having a large capacity is about 5 to 10 times as an example of the capacity of the second and third power storage modules C1 and C2 that can be charged at high speed. Suppose that However, this multiple does not limit the present invention.

(High-speed energy storage device)
The C rate is used as an index expressing the charging speed of the storage battery or capacitor. The C rate is a unit in which the current value when charging the entire capacity of the storage battery in 1 hour is 1C.
A high power density storage element with a large chargeable / dischargeable current per unit time means that the capacity after charging with a current of 100 C from the state of discharging to the minimum value of usable voltage is charged with the current of 1 C from the discharged state. It is defined as a power storage element having a performance of 50% or more with respect to the later capacity. Hereinafter, the high power density storage element is also referred to as a high speed storage element. Specifically, a lithium ion capacitor (hereinafter also referred to as “LIC”), an electric double layer capacitor (hereinafter also referred to as “EDLC”), and a redox capacitor are applicable.

The high energy density storage element having a large chargeable / dischargeable capacity refers to a secondary battery, and specifically, a lithium ion battery (hereinafter also referred to as “LIB”), a nickel metal hydride battery, a nickel cadmium battery, and a lead storage battery. can give.
The maximum charging speed of a general LIB is about 1C, and even if it is optimized to improve the charging / discharging speed at the expense of capacity, it is about 20C. This reason is derived from the electrochemical reaction rate at the positive electrode and the negative electrode of the storage battery, so it is difficult in principle to increase the charge rate beyond that. On the other hand, high-speed power storage elements such as LIC and EDLC can be charged at several hundred C.

(Rated voltage)
For storage batteries, the maximum value of charging voltage (hereinafter also referred to as maximum rated voltage or upper limit voltage) and the minimum value of discharge voltage (hereinafter also referred to as minimum rated voltage or lower limit voltage) in consideration of safety, life, etc. May be stipulated. A voltage between the minimum value of the discharge voltage and the maximum voltage of the charging voltage is the usable voltage of the storage battery. In a storage battery, charging to a voltage exceeding the maximum rated voltage is referred to as overcharging, and discharging to a voltage exceeding the minimum rated voltage is referred to as overdischarging.

In the first charging step shown in FIG. 4 (a), the power stored in the second power storage module C1 that can be charged at high speed is quickly charged into the third power storage module C2 that can be charged at high speed, and an emergency situation, for example, complete A moving object that has fallen into a discharged state can be operated again. At this time, the first switch D1 is in the first connection state, and the second switch D2 is in the third connection state. The power supply switch D3 is ON.
In the second charging step shown in FIG. 4B, the power stored in the large-capacity first power storage module B1 can be quickly charged and waited on the second power storage module C1 capable of high-speed charging. At this time, the first switch D1 is in the second connection state, and the power feeding switch D3 is in the OFF state.
In the third charging step shown in FIG. 4C, the power stored in the third power storage module C2 that can be charged at high speed can be quickly charged and waited in the large capacity fourth power storage module B2. At this time, the second switch D2 is in the fourth connection state, and the power feeding switch D3 is in the OFF state.

In the fourth charging step shown in FIG. 4D, the power of the external power source S is charged to the large capacity first power storage module B1 for a long time with a small current. At this time, the first switch D1 is in the first connection state.
In the state where the first charging step and the fourth charging step shown in FIG. 4 (e) are performed simultaneously, the power of the external power source S is charged to the large capacity first power storage module B1 with a small current for a long time. The chargeable second power storage module C1 can be quickly charged and waited. At this time, it is a seventh connection state in which all three contacts related to the first switch D10 are connected. The power feeding switch D3 is OFF.
In the fifth charging step shown in FIG. 4 (f), the power of the external power source S can be quickly charged and waited for the second power storage module C1 that can be charged at high speed. At this time, the first switch D10 is in the eighth connection state. The power feeding switch D3 is OFF.

  According to the charging systems 100 and 101 according to the embodiments of the present invention shown in FIGS. 1 to 4, during busy periods, the storage battery of the power feeding devices 50 and 51 is charged frequently to the charging devices 60 and 61. It is possible to quickly cope with the time required for recovering the power supply capability due to the rapid charging using the high-speed charging element. That is, when the frequency with which the first power storage module B1 is in a discharged state is high, a system can be provided that can charge the second power storage module C1 directly from an external power source as necessary. Then, by rapidly charging from the second power storage module C1 to the third power storage module C2, it is possible to shorten the time during which one power receiving device (moving body) occupies the power feeding device (station). In addition, when the fourth power storage module B2 is in a discharged state, the shortage of charging to the fourth power storage module B2 can be compensated for by driving the load directly with the discharge from the third power storage module C2 as necessary. Is possible. For this purpose, the first switches D1 and D10, the second switches D2 and D20, and the power feeding switch D3 are appropriately switched. By doing so, the second power storage module C1 that can be charged in a short time with respect to the third power storage module C2 that uses a capacitor capable of rapid charge and discharge as a power storage element is connected via the power supply terminal A1 and the power reception terminal A2. Connect. As a result, a small external power source for supplying power to the power supply apparatus is sufficient. In addition, it is possible to reduce a non-operation time in which power cannot be supplied because the power receiving device is in a discharged state. Hereinafter, it is assumed that the charging system 100 is also included in the description of the charging system 101.

(Storage module 10)
The power receiving device 60 may use the power storage module 10 including a power storage unit in which a plurality of high-speed power storage elements are connected in series according to FIG. 5 in an application that requires charging / discharging with an instantaneous large current. Conceivable. FIG. 5 is a schematic circuit diagram showing an example of a power storage module used in the charging system of the present invention. The power storage module 10 shown in FIG. 5 is an example applied to the third power storage module C2 shown in FIGS.

  The third power storage module C2 illustrated in FIGS. 1 and 2 includes the power storage module 10 illustrated in FIG. The power storage module 10 includes a power storage unit K, a switch circuit 14, a bypass circuit Xi (i = 1 to N), a bypass control unit G, and first to third timing control units 71 to 73. Has been. The power storage unit K includes a plurality of power storage units Ei (i = 1 to N). This is also indicated as a power storage unit Ei. The switch circuit 14 is connected to the power storage unit K in series. Bypass circuits Xi (i = 1 to N) are connected in parallel to the power storage units Ei (i = 1 to N), respectively. In the bypass circuit Xi (i = 1 to N), a bypass switch Fi (i = 1 to N) and a resistor Ri (i = 1 to N) are inserted in series, respectively. The bypass control unit G includes a voltage detector 13a and detects the voltage of each power storage unit Ei. The bypass control unit G performs ON / OFF control of the bypass switch Fi based on the detection value detected by the voltage detector 13a. When the switch Fi connected in parallel for each power storage unit Ei is turned ON, the bypass path is conducted. The bypass control unit G also performs ON / OFF control of the charging switch J.

  The power storage units E1 and E2 shown in FIG. 5 are composed of high-speed power storage elements C21 and C22, respectively. The power storage unit Ei is not limited to one that includes one high-speed power storage element, but may include a plurality of high-speed power storage elements connected in parallel. Further, the total amount of power when the power storage unit Ei included in the second power storage module C1 on the power supply device 51 side is fully charged is the power when the power storage unit included in the third power storage module C2 on the power reception device 61 side is fully charged. More than the total amount is convenient for fast charging. Here, the time of full charge means a state where the battery is charged up to the maximum rated voltage.

  When the current output from the power storage unit K is output to the outside, the power storage module 10 illustrated in FIG. 5 loads the terminals 15a and 15b according to the sixth connection state of the second switch D20 illustrated in FIG. L is connected. On the other hand, during charging, the power supply switch D3 shown in FIGS. 1 and 2 is turned on so that a charging voltage is applied to the terminals 15a and 15b. During charging, the charging switch J is turned on by the bypass control unit G inside the power storage module 10, whereby a charging voltage is applied between the terminals 15a and 15b, and the power storage unit K is charged. Further, when the charging switch J is turned off by the bypass control unit G, the charging of the power storage unit K is stopped. The bypass control unit G is configured such that the bypass switch Fi is ON / OFF controlled based on a detection value obtained by detecting the voltage of each power storage unit Ei by the voltage detector 13a.

  The diode 141 connected in parallel with the charging switch J is the diode 141 regardless of whether the charging switch J is ON or OFF when the power storage unit K is used, that is, when the load L is connected between the terminals 15a and 15b. When the forward current flows through the capacitor K, the power storage unit K can be discharged. The charge switch J is preferably a MOSFET, a thyristor, a triac, or the like, and can be selected according to a voltage value or a current value that is a use condition of the power storage module 10.

In particular, when many power storage units Ei are connected in series and the voltage of the power storage module 10 is set to a high voltage, withstand voltage resistance such as an IGBT element (insulated gate bipolar transistor) or a GTO element (gate turn-off thyristor) as the charge switch J. It is preferable to use a switch element having a high height.
As an example of a preferred embodiment, a MOSFET (BBS3002 manufactured by Sanyo Semiconductor Co., Ltd.) can be used for the charge switch J. The bypass switch Fi can be set to a value of the resistance Ri = 800 mΩ using a MOSFET element (BSC016N03MSG manufactured by Infineon Technologies, Inc.).

In the first timing control unit 71 shown in FIG. 5, the voltage detector 13a detects the voltage of the power storage unit Ei (i = 1 to N), and at least one of the power storage units Ej is equal to or higher than the charging target voltage V1. The timing is set so that the charging switch J is switched from ON to OFF when the first predetermined time T1 has elapsed after the detection (see S908 in FIG. 9 and FIG. 10).
The second timing control unit 72 detects that the voltage detector 13a detects the voltage of the power storage unit Ei (i = 1 to N), and that the power storage unit Ej is equal to or higher than the charging target voltage V1. When the second predetermined time T2 has elapsed, the timing for turning the bypass switch Fj from OFF to ON is set (see S940 in FIG. 11 and FIG. 12).

  In addition, the third timing control unit 73 sets a timing when a third predetermined time T3 (not shown in the diagram), which will be described later, has elapsed. As the timing control units 71, 72, 73, for example, a circuit in which a time constant is set in a timer IC with a resistor and a capacitor can be used. Here, when a variable resistor is used as at least one resistor of these circuits, the set time can be arbitrarily changed.

(Balancing)
In order to repeatedly charge and discharge the power storage module 10, it is considered essential to perform balancing. Hereinafter, balancing will be described. Balancing means the control for adjusting the power storage module 10 including a power storage unit in which a plurality of power storage units are connected in series so that there is no voltage variation between the power storage units during the above-described CCCV charging. A state in which the voltage between the power storage units varies is also referred to as unbalance. In the power storage module 10, imbalance occurs between the storage batteries in the power storage module 10 at the time of charging and discharging. Such voltage imbalance occurs due to a difference in capacity due to manufacturing variation of each storage battery, a difference in environmental temperature due to arrangement in the power storage module 10, and the like.

  In general, the lithium ion battery also has a function of preventing overcharge and overdischarge and constitutes the power storage module 10. For this reason, if voltage imbalance occurs in the power storage module 10 using a plurality of power storage units, the voltage of one storage battery in the power storage module 10 reaches the upper limit voltage, so that other storage batteries can be charged. Can no longer be charged.

  When the voltage of one storage battery reaches the minimum value of the discharge voltage, the other storage batteries can no longer be discharged even if they can be discharged. Such a configuration of the power storage module 10 cannot sufficiently bring out the performance of each storage battery constituting the power storage module 10, and reduces the overall capacity of the power storage module 10. In order to eliminate the voltage imbalance described above, various voltage balancing methods have been developed. As a conventional general balancing method, there is a method in which a bypass circuit in which a resistor and a switch element are connected in series is connected in parallel to each power storage unit.

(Bypass circuit)
As shown in FIG. 5, the power storage module 10 constituting the third power storage module C2 includes a bypass circuit X1 connected in parallel to the power storage unit E1, a bypass circuit X2 connected in parallel to the power storage unit E2, and these bypasses A bypass control unit G that controls the circuit Xi and first to third timing control units 71 to 73 are provided. Moreover, the bypass control part G is provided with the voltage detector 13a which detects the voltage value of the electrical storage unit Ei separately. The 1st-3rd timing control parts 71-73 set the 1st-3 predetermined time T1-T3 for the heat_generation | fever countermeasure mentioned later.

  The bypass circuit X1 includes a resistor R1 and a bypass switch F1 connected in series. Similarly, the bypass circuit X2 includes a resistor R2 and a bypass switch F2 connected in series. When the bypass control unit G turns on the bypass switch F1 during charging, charging to the power storage unit E1 is bypassed. Therefore, the power of the power storage unit E1 is generated and consumed by the resistor R1 of the bypass circuit without being charged. The Further, when the bypass control unit G turns off the bypass switch F1, the power storage unit E1 is charged. Conversely, when the power storage module 10 is used, the bypass switch F1 is turned off and the power storage unit E1 is discharged without waste.

  As shown in FIG. 5, since the bypass circuit X1 and the bypass circuit X2 have the same configuration, the bypass circuit X2 operates in the same manner as the bypass circuit X1 described above under the control of the bypass control unit G. . However, the bypass controller G individually detects the voltage of the power storage unit Ei (i = 1 to N) by the voltage detector 13a, and the bypass circuit Xi (i = 1 to N) based on the detected voltage value. Each of the bypass switches Fi (i = 1 to N) that conducts is turned ON / OFF individually. Further, the bypass control unit G controls to turn on the charging switch J at the start of charging and to turn off the charging switch J at the end of charging or at the interruption based on the control pattern according to the charging state.

  The high-speed charging elements constituting the power storage unit Ei (i = 1 to N) of the power storage module 10 are suitable in the order of LIC, EDLC, and redox capacitor. In particular, LIC or EDLC that has a small internal resistance and can make the maximum charging current 100C or more is suitable. Furthermore, LIC is optimal at the present time because it has less self-discharge and higher energy density than EDLC. In the above description, FIG. 5 shows an example in which two power storage units are connected in series for the sake of simplicity. However, the number of power storage units is not limited to two, and depends on the required voltage. The quantity can be set appropriately.

(First embodiment: rapid charging)
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. The first embodiment is intended for quick charging. FIG. 6 is a flowchart showing a charging method according to the first embodiment of the present invention. As shown in FIGS. 1, 2, and 6, the power feeding terminal A1 and the power receiving terminal A2 are electrically connected (step S600). Next, the voltage of the second power storage module C1 is detected by a detection / calculation unit (not shown) included in the control unit 1 shown in FIG. 1, and the dischargeable capacity is calculated (step S601). Then, the detection / calculation means (not shown) included in the control units 1 and 21 shown in FIGS. 1 and 2 detects the voltage of the third power storage module C2 and calculates its chargeable capacity (step S602). Next, the control units 1 and 21 calculate the charging time and determine whether or not charging is possible (step S603). If charging is not possible (step S603: No), the process waits (step S604). When the standby time has elapsed in step S605, the process returns to step S601.

  On the other hand, if charging is possible (step S603: Yes), the power supply switch D3 is turned on (step S605). Next, it is judged by the control part 1 whether the voltage of the 2nd electrical storage module C1 is below a lower limit voltage (step S606). If the voltage of the second power storage module C1 is equal to or lower than the lower limit voltage (step S606: Yes), the power supply switch D3 is turned off (step S609). Then, the electrical connection between the power feeding terminal A1 and the power receiving terminal A2 is released (step S610).

  On the other hand, if the voltage of the 2nd electrical storage module C1 is not below a minimum voltage (step S606: No), it will be judged by the control part 1 whether the voltage of the 2nd electrical storage module C1 is more than an upper limit voltage (step S607). ). If the voltage of the 2nd electrical storage module C1 is more than an upper limit voltage (step S607: No), the electric power feeding switch D3 will be turned OFF (step S609). Then, the electrical connection between the power feeding terminal A1 and the power receiving terminal A2 is released (step S610).

  On the other hand, if the voltage of the second power storage module C1 is not equal to or higher than the upper limit voltage (step S608: No), whether or not the ON time of the power feeding switch D3 is equal to or higher than the upper limit is measured by a time measurement (not shown) included in the control unit 1. It is determined by means (step S608). If the ON time of the power supply switch D3 is equal to or greater than the upper limit (step S608: Yes), the power supply switch D3 is turned OFF (step S609). Then, the electrical connection between the power feeding terminal A1 and the power receiving terminal A2 is released (step S610). On the other hand, if the ON time of the power supply switch D3 is not longer than the upper limit (step S608: No), the process returns to step S606 and the above-described steps are repeated. In addition, the upper limit voltage and the lower limit voltage described above are values defined as usable voltages and are as described above. In addition, it is a safe charging method for the storage battery that the control unit 1 manages the ON time of the power supply switch D3 within an appropriate range in step S608.

“Steps S605 to S609” according to the present embodiment correspond to “first steps” according to the present invention.
Thus, according to the charging method shown in the first embodiment, when the frequency of the first power storage module B1 of the power feeding device 51 in a busy state is high, the first switch D1 and the second switch D2 are used. Are appropriately switched to supply power to the third power storage module C2 that uses a capacitor that can be charged and discharged quickly as a power storage element. By connecting the terminal A1 and the power receiving terminal A2 for quick charging, it is possible to compensate for the insufficient charging of the fourth power storage module B2. As a result, a small external power source for supplying power to the power supply apparatus is sufficient. In addition, it is possible to reduce a non-operation time in which power cannot be supplied because the power receiving device is in a discharged state.

(Second embodiment: fast charging + balancing)
Hereinafter, the second embodiment of the present invention will be described mainly with reference to FIGS. The second embodiment is aimed at fast charging and balancing. FIG. 7 is a flowchart showing a charging method according to the second embodiment of the present invention. This flowchart shows an example in which the power storage unit Ei of the power storage module 10 shown in FIG. 5 is charged by balancing so that the voltage of all Ei falls within a predetermined range. FIG. 8 is a diagram showing the relationship between the voltage of the power storage unit and time by the charging method (FIG. 7) according to the second embodiment of the present invention.

  The power storage unit Ei performs balancing between the high-speed power storage elements C21 and C22 while performing the above-described CCCV charging. First, at the time of charging, power feeding terminals A1 and A1 'are connected to power receiving terminals A2 and A2'. Then, the power storage unit Ei is charged with a constant current until the voltage between the terminals 15a and 15b reaches a voltage value (hereinafter also referred to as a charging index) V20 determined as a charging index. Thereafter, the power storage unit Ei is charged at a constant voltage so as to maintain the charging target voltage V20 between the power receiving terminals 15a and 15b. Note that the terminals 15a and 15b shown in FIG. 5 are substantially the same because they are always connected to the power receiving terminals A2 and A2 ′ shown in FIGS. 1 and 2, but are represented for convenience of explanation along the drawings. Use as appropriate.

  Further, when the voltage between the terminals 15a and 15b reaches the charging target voltage V20 due to constant current charging, the fully charged state is insufficient due to the Ir voltage drop due to the internal resistance of the power storage unit Ei and has not yet reached. . In order to satisfy this Ir voltage drop, it is possible to charge to nearly full charge by performing constant voltage charging over time while gradually reducing the current so as to reduce the Ir voltage drop causing the Ir voltage drop. it can.

The charging target voltage V20 of the power storage module 10 is determined from the maximum voltage value that is the charging target of each power storage unit Ei, that is, the number N of serial connections between the charge target voltage V1 and the power storage unit Ei. That is, the charging target voltage V20 is determined by the following equation (1).
V20 = V1 × N (1)
In the power storage unit Ei, the charging target voltage V1 is set between the upper limit charging voltage of the high speed power storage elements C21 and C22 and the lower limit discharging voltage. Specifically, it is set to a value that is somewhat closer to the charge upper limit voltage than an intermediate value between the charge upper limit voltage and the discharge lower limit voltage.

  In addition, the bypass control unit G turns off the charging current once by the charging switch J based on the fact that the voltage of the power storage unit Ei has reached the charging target voltage V1, but immediately after that, the voltage of the power storage unit Ei However, when it is detected to be lower by the Ir voltage drop, the bypass control unit G may perform an unstable operation of repeatedly turning on again. In order to avoid this unstable operation, the relationship between the detection voltage of the power storage unit Ei and the ON / OFF control of the charging current is set to have hysteresis.

That is, the threshold value for ON / OFF control of the charging current is widened so that it is easy to continue OFF once it is turned off, and conversely, it is easy to continue ON once it is turned on. Therefore, the charging resumption voltage V2 set lower by a predetermined width than the charging target voltage V1 is set to the following expression (2).
V2 = V1− (Ir voltage drop + α) (2)
Therefore, when charging the LIC having the internal resistance of 13 mΩ with the charging current I = 30 A and the charging target voltage V1 = 4.0V, the charging resumption voltage V2 = V1−Ir = less than 3.61V, for example, 3.5V is set. .

  As shown in FIG. 7, before the start of charging, the bypass control unit G turns on the charging switch J and turns off the bypass switch Fi (step S700). And the voltage detector 13a detects the voltage of the electrical storage unit Ei during constant current charge (step S701). Next, the bypass control unit G determines whether or not the detected voltage of the power storage unit Ei is equal to or higher than the charging target voltage V1 (step S702). As a result, if it is not equal to or higher than the charging target voltage V1 (step S702: No), the voltage detector 13a continues to detect the voltage of the power storage unit Ei again and waits until it reaches the charging target voltage V1. 7 and 9, bypass circuits X1, X2, ..., Xi, ..., Xn, bypass switches F1, F2, ..., Fi, ..., corresponding to a large number of E1, E2, ..., Ei, ..., En. Fn and resistors R1, R2,..., Ri,.

  Further, when there is a power storage unit Ej that has reached the charge target voltage V1 or higher (step S702: Yes), the bypass control unit G turns on the bypass switch Fj of the bypass circuit Xi connected in parallel with the power storage unit Ej. . If the bypass switch Fj is turned on, the charging current bypasses the resistor Rj of the bypass circuit Xj that is turned on (step S703). In this way, the bypass switch whose bypass circuit is turned on is denoted by Fj, the corresponding resistor is denoted by Rj, and the power storage unit is denoted by Ej.

  At this time, a small amount of current also flows from the power storage unit Ej connected in parallel to the resistor Rj to the resistor Rj, so that the voltage value of the power storage unit Ej decreases. The voltage drop rate increases as the resistance value of the resistor Rj decreases. This phenomenon is as shown by the slope decreasing from the voltage V1 to V2 in the sawtooth section of FIG. Here, the voltage detector 13a continues to detect the voltage of the power storage unit Ej corresponding to the bypass switch Fj that is turned on, and waits until the charging target voltage V1 is reached (step S704).

  Next, the bypass control unit G determines whether or not the voltage value of the power storage unit Ej whose bypass circuit is turned on is equal to or lower than the charging resumption voltage V2 (step S705). When the voltage value of the power storage unit Ej is equal to or higher than the charging restart voltage V2, the bypass switch Fj is kept ON, and the process returns to Step S704 (No at Step S705). On the other hand, when there is a power storage unit having a voltage value of V2 or less (step S705: Yes), the power storage unit Ej having the charge resumption voltage V2 or less is turned off by turning off the bypass switch Fj connected in parallel to the power storage unit Ej. A charging current is supplied to the terminal (step S706). Further, the voltage detector 13a continues the voltage detection of all the power storage units Ei (step S707).

  Further, the bypass control unit G determines whether or not the voltage values of all the power storage units Ei are in the range of the charging target voltage V1 or less and the charging resumption voltage V2 or more (step S707). The power storage unit Ej having a voltage value in the range of V1 to V2 (step S707: Yes) completes charging and voltage equalization (step S708). On the other hand, the power storage unit Ei whose voltage value is outside the range of V1 to V2 (step S707: No) returns to step S701 and repeats detecting the voltage of the power storage unit Ei. Thereafter, in the power storage module 10, the above-described operation is repeated.

  The start and end of charging are controlled by the control unit 1 of the power feeding device 50 in which the terminals 15a and 15b are connected as the power receiving terminals A2 and A2 ′. When the charging end condition set in advance by the power supply apparatus 50 is reached, the power supply apparatus 50 ends the charging. At this time, the bypass control unit G stops in any state of step S701 to step S708 shown in FIG. The following conditions correspond to the charge termination conditions set in advance in the power supply apparatus 50, and when at least one of them is satisfied, the power supply apparatus 50 stops the charging current. In the power feeding device 50, if a program (not shown) provided in the control unit 1 and a computer that executes the program recognize that one of the following conditions is satisfied, charging is performed by turning off the power feeding switch D3. Stop.

When a predetermined time T10 has elapsed from the start of charging (FIG. 8).
-In CCCV charging, when a predetermined time has elapsed since switching from CC charging to CV charging.
-In CCCV charging, when the amount of current flowing during CV charging becomes smaller than a predetermined value.
-In CCCV charging, when the time change of the amount of current flowing during CV charging becomes smaller than a predetermined value.

FIG. 8 shows time on the horizontal axis and the charging voltage of the power storage unit on the vertical axis. As shown in FIG. 8, according to the charging method according to the second embodiment shown in FIG. 7, the voltage value of one power storage unit of power storage module 10 can be kept in the range of V2 to V1.
However, when the charging of the power storage module 10 shown in FIG. 8 is controlled as described above, the following problem occurs. That is, for example, if the charging end condition set in the power supply apparatus is the elapse of the charging time T10, the charging module 10 starts the bypass operation until the time T10 elapses and the charging ends. Since a considerable portion of the current supplied to the electric storage body flows through the resistor Ri, it is consumed as heat. This heat increases the temperature in the power storage module 10 and may reach a temperature at which it cannot operate unless forced cooling is performed.
In the charging method according to the second embodiment described above, the charging switch J after completion of charging is OFF. The timing at which the charging switch J is turned from OFF to ON is detected by one of the following methods.

A signal for controlling ON and OFF of each bypass switch Fi is used, and when it is detected that all bypass switches Fi are OFF, charging switch J is turned ON.
When the voltage of the power storage unit Ei is equal to or lower than the charging restart voltage V2, the charging switch J is turned on.
When the power storage module 10 is used (discharged), the current flowing through the diode 141 of the switch circuit 14 is detected, and the charge switch J is turned on when the detected current exceeds a predetermined current value.

The “step S700” according to the present embodiment corresponds to the “first step” according to the present invention. Further, “steps S701 to S703” according to the present embodiment correspond to “second step” according to the present invention. “Steps S704 to S706” according to the present embodiment correspond to “third step” according to the present invention.
The voltage of the power storage unit may be equal to or higher than the charging target voltage V1, but the time T10 shown in FIG. 8 can be set within a range not exceeding the maximum value of the charging voltage or an overcharge protection voltage (not shown). . In addition to the method of setting the time T10, by setting the value of the target charging voltage V1 to be slightly smaller than the originally desired voltage value, the voltage of the power storage unit can be set to the charging upper limit voltage or an overcharge protection voltage not shown It can be controlled not to reach.

The above-described operation of bypassing the current to the resistor is performed for the purpose of voltage balancing between the power storage units included in the power storage unit. However, reducing the number of times of bypassing as described above and cutting off the charging current after a lapse of a certain time may make it difficult to achieve the purpose of voltage balancing between the power storage units.
However, in the charging method of the second embodiment, even if voltage imbalance remains slightly immediately after the first charging, the load is connected and discharged after the charging is completed, and the operation of charging again is repeated a plurality of times. It does not increase cumulatively and approaches a more balanced state. That is, when the power storage module 10 is actually mounted and used in a mobile device or an electronic device, the high-speed power storage element or the power storage unit of the power storage unit can be operated without voltage variation.

(Fever problem)
The balancing by the bypass circuit has a drawback of generating heat. That is, in the power storage module 10, the current that flows to the bypass circuit Xi side is changed to heat by the resistor Ri. The amount of heat generated at this time is proportional to the square of the current. And by changing the storage battery from the high energy density storage element to the high output density storage element, a large amount of heat is generated when a large charging current for high-speed charging is applied, and the temperature in the storage module 10 is significantly increased. The life of the high-speed power storage elements C21 and C22 in the power storage module 10 may be shortened.
The temperature rise in the power storage module 10 can be avoided by providing a heat radiating fin or a heat radiating fan for radiating the heat generated by the current. However, providing such a member increases the overall size of the power storage module 10.

(Measures against heat generation)
As a countermeasure against heat generation, the power storage module 10 detects that the voltage detector 13a detects that the voltage value of any one of the power storage units Ei is equal to or higher than the charge target voltage V1 when the charging switch J is turned off from ON. To a first timing control unit (for example, the first timing control unit 71 shown in FIG. 5) that takes the timing when the first predetermined time T1 has elapsed. Details will be described later with reference to FIGS.

  In addition, as a countermeasure against heat generation, the power storage module 10 determines the timing at which each second bypass switch Fi is turned from OFF to ON, and the voltage value of the power storage unit Ei to which the second bypass switch Fi is connected is determined by the voltage detector 13a. A second timing control unit (for example, the second timing control unit 72 shown in FIG. 5) is provided that sets a timing at which a second predetermined time T2 has elapsed since it was detected that the charging target voltage V1 or higher was detected. Details will be described later with reference to FIGS.

  As a further countermeasure against heat generation, the power storage module 10 determines when the voltage value of the power storage unit power storage unit Ei to which the second bypass switch Fi is connected is determined by the voltage detector 13a. A third timing control unit (for example, the third timing control unit shown in FIG. 5), which has a timing at which a third predetermined time T3 (time chart not shown) has elapsed since it was detected that the charge restart voltage V2 or less was detected. 73).

(Third embodiment: quick charge + rapid cell balance + heat generation suppression)
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment is intended for rapid charging, rapid cell balance, and suppression of heat generation. FIG. 9 is a flowchart showing a charging method according to the third embodiment of the present invention. FIG. 10 is a diagram showing the relationship between the voltage of the power storage unit and time by the charging method (FIG. 9) according to the third embodiment of the present invention. In FIG. 10, the horizontal axis indicates time, and the vertical axis indicates the charging voltage of the power storage unit Ei. A time T <b> 10 indicated on the horizontal axis is a charging time set in the power feeding device 50. Also, in the flowchart of FIG. 9, the processing from step S902 to S907 is performed in the same manner as the processing from step S701 to S706 in the flowchart shown in FIG.

  As shown in FIG. 9, at the start of charging, the bypass controller G turns off the charging switch J and also turns off the bypass switch Fi (step S900). Then, by turning on the charging switch J, a charging current is passed through the power storage unit Ei (step S901). At the start of charging, the voltage detector 13a of the bypass control unit G detects the voltage of the power storage unit Ei while charging with constant current (step S902). When the voltage detection value of the power storage unit Ei is not equal to or higher than the charging target voltage V1 (step S903: No), the bypass control unit G stands by until the charging target voltage V1 is reached while continuing the voltage detection of the power storage unit Ei.

  Further, the bypass control unit G detects the voltage of the power storage unit Ei using the voltage detector 13a, and determines whether or not the voltage is equal to or higher than the charging target voltage V1 (step S903). If there is a power storage unit Ej having a charge target voltage V1 or higher among the power storage units Ei (step S903: Yes), the bypass switch of the bypass circuit Xj connected in parallel with the power storage unit Ej having the charge target voltage V1 or higher. Fj is turned ON, and the charging current is bypassed to the resistor Rj (step S904). And the voltage detection of the electrical storage unit Ej which has reached the charge target voltage V1 or more is continued by the voltage detector 13a (step S905).

  The charge target voltage V1 of the first to third embodiments described above is set between the charge upper limit voltage and the discharge lower limit voltage of the high-speed power storage element incorporated in the power storage unit. Generally, it is set between the charging upper limit voltage from an intermediate value between the charging upper limit voltage and the discharging lower limit voltage. Further, the minimum voltage value (charging resumption voltage V2) of the target voltage at the time of charging is set to a value between 0.9 times and 1.0 times the maximum output voltage value V1 of the target voltage. More preferably, it is set to a value between 0.95 times and 1.0 times, and more preferably a value between 0.97 times and 1.0 times. The setting of the charging resumption voltage V2 is significantly different from the conventional technique in which the charging resumption voltage V2 is set to V2 = V1− (Ir + α) so as not to cause chattering. It is possible to make it.

  In step S904 shown in FIG. 9, the bypass switch Fj is turned on, and the current flows through the bypass circuit X1 including the power storage unit Ej and the resistor Rj connected in parallel thereto, and the current is newly increased. A voltage drop is caused by the product of the increased current and the internal resistance r of the power storage unit Ej. Due to the voltage drop, the value of the resistor Ri is determined so that the voltage of each power storage unit Ei does not become equal to or lower than the charging restart voltage V2. Specifically, a value obtained by dividing the resistance value of the resistor Ri by the internal resistance value r of the power storage unit Ei may be set within a range of 9.0 to 93.6. Preferably, the value may be set within the range of 18.5 to 93.6. More preferably, the value may be set within the range of 32.7 to 93.6.

  After the bypass switch Fj is turned on in step S904, the voltage detector 13a continues to detect the voltage of the power storage unit Ej corresponding to the bypass switch Fj that is turned on (step S905). Next, the bypass control unit G determines whether or not the voltage value of the power storage unit Ej whose bypass circuit is turned on is equal to or lower than the charging resumption voltage V2 (step S906). When the voltage value of the power storage unit Ej is equal to or higher than the charging restart voltage V2, the bypass switch Fj is kept ON, and the process returns to step S905 (No in step S906). On the other hand, when there is a power storage unit having a voltage value of V2 or less (step S906: Yes), the power storage unit Ej having a charge resumption voltage V2 or lower is turned off by turning off the bypass switch Fj connected in parallel to the power storage unit Ej. A charging current is supplied to the terminal (step S907).

  Then, as shown in FIG. 10, it is determined whether or not the first predetermined time T1 or more has elapsed since the bypass switch Fj was turned off (step S908). When the time T1 or more has elapsed (step S908: Yes), the charging switch J is turned off (step S909), the charging current is interrupted, and the charging is terminated (step S910). Note that the time measurement start T0 of the time T1 is a time at which at least one of the bypass switches Fi, that is, the bypass switch Fj starts its operation first. On the other hand, when the time T1 has not elapsed (step S908: No), the process returns to step S902, and as described above, the voltage detector 13a detects the voltages of all the power storage units Ei that are continuing constant current charging. Wait while.

  Note that “steps S900 to S901” according to the present embodiment correspond to “first step” according to the present invention. Further, “steps S902 to S904” according to the present embodiment correspond to “second step” according to the present invention. “Steps S905 to S907” according to the present embodiment correspond to “third step” according to the present invention. Further, “steps S908 to S910” according to the present embodiment corresponds to “fourth step” according to the present invention.

Further, as shown in FIG. 10, since the accurate charging start time T0 cannot be ascertained before charging, the time T10 needs to be set longer than the estimated T0. According to the charging method of the third embodiment, since the charging current is turned off at time T0 + T1, charging ends without waiting for time T10 to elapse.
From the above, according to the current method of the third embodiment, the time during which the current flows through the resistor Ri can be shortened, so that the heat generation in the resistor Ri can be suppressed. In the third embodiment, charging is not performed during a period between time T0 + T1 and time T10 indicated by a dotted line in FIG. According to the third embodiment, there is no problem regarding imbalance due to the characteristics of the power storage unit Ei and the setting of the charge resumption voltage V2.

(Fourth embodiment: quick charge + rapid cell balance + heat generation suppression)
The fourth embodiment will be described with reference to FIGS. The fourth embodiment is intended for rapid charging, rapid cell balance, and heat generation suppression. FIG. 11 is a flowchart for explaining a charging method according to the fourth embodiment of the present invention. FIG. 12 is a diagram illustrating the relationship between the voltage of the power storage unit and time by the charging method according to the fourth embodiment of the present invention. Of steps S900 to S910 shown in FIG. 11, the processes other than step S940 are performed in the same manner as the processes of steps S900 to S903 and steps S905 to S910 of the third embodiment shown in FIG. Therefore, the same process is indicated by the same step number, and description thereof is omitted. Step S940, which is a difference, will be described.

  Even if Step S903 shown in FIG. 11 is Yes, the process waits until the time T2 elapses. In other words, even if the power storage unit Ej that has reached the charge target voltage V1 or higher is detected, the process waits until the time T2 shown in FIG. 12 elapses. Then, after the time T2 has elapsed, the bypass control unit G turns on the bypass switch Fj of the bypass circuit Xj connected in parallel with the power storage unit Ej to bypass the charging current to the resistor Rj (step S940).

  In the bypass control unit G, the voltage detector 13a detects that the voltage of the power storage unit is equal to or higher than the charging target voltage V1 at time T0 shown on the horizontal axis of FIG. Then, the bypass switch Fi is turned on after the second predetermined time T2 has elapsed. For this reason, since the time during which current flows through the resistor Ri between the time T0 and the end of charging is reduced, heat generation at the resistor Ri can be suppressed. The time T10 represents the charging time set by the power supply apparatus 50. During the period between time T0 + T1 and time T10, the power storage unit Ei is not charged.

The time T2 shown in FIG. 12 is set to a value obtained by multiplying the value of the capacitance of the power storage unit by the charging current value and the coefficient β. At this time, the unit of the time T2 is seconds. The coefficient β is set in the range of 0.005 to 1.5, more preferably in the range of 0.01 to 0.5, and still more preferably in the range of 0.02 to 0.3.
After the bypass switch Fj is turned on in step S940, the voltage detector 13a continues to detect the voltage of the power storage unit Ej corresponding to the bypass switch Fj that is turned on (step S905). Steps S905 to S910 are as described with reference to FIG.

  Note that “steps S900 to S901” according to the present embodiment correspond to “first step” according to the present invention. Further, “steps S902 to S940” according to the present embodiment corresponds to “second step” according to the present invention. “Steps S905 to S907” according to the present embodiment correspond to “third step” according to the present invention. Further, “steps S908 to S910” according to the present embodiment corresponds to “fourth step” according to the present invention. Among these, the second step and the third step are repeatedly executed.

In this second step, after the second predetermined time T2 has elapsed after the voltage value has become equal to or higher than the charging target voltage V1, the bypass switch Fj of the bypass circuit Xj corresponding to the power storage unit Ej is turned on. (Step S940), the current flowing through the power storage unit Ej is bypassed to the bypass circuit Xj.
As described above, according to the charging system and the charging method according to the fourth embodiment described above, in the power storage unit K configured by connecting the high-speed power storage elements C21 and C22 in series, the amount of heat generated due to balancing during charging is suppressed, In addition, the balancing state can be kept good.

Although not shown, in the second to fourth embodiments, an overcharge protection circuit or an overdischarge protection circuit may be installed separately from the power storage module 10. The set voltage of the overdischarge protection circuit is determined by the lower limit voltage of the high speed storage element. The set voltage of the overcharge protection circuit is preferably provided between the upper limit voltage of the high-speed power storage element, that is, between the maximum rated voltage and the charge target voltage V1.
In addition, a switch element that cuts off the charging current in the overcharge protection circuit may be used as the power supply switch D3 and the charge switch J. In this case, the bypass control unit G can be realized by ON / OFF control of the switch element of the overcharge protection circuit. The charging system and the charging method according to the present embodiment have been described above. According to the charging system and the charging method according to the present embodiment, a power receiving device from a power feeding device that relies on a small-scale, low-capacity external power source, or a power feeding device that is installed only at a low voltage power line. It is possible to provide a charging system and method capable of rapidly charging a battery.

DESCRIPTION OF SYMBOLS 1, 2 Control part 10 Power storage module 13 Bypass control part 13a Voltage detector A1, A1 'Feeding terminal (15a, 15b terminal)
A2, A2 ′ power receiving terminals B1, B2 First and fourth power storage modules (consisting of high energy density power storage elements)
C1, C2 2nd and 3rd power storage modules (consisting of high power density storage elements)
C21, C22 power storage element (high power density power storage element)
D1, D2 First and second switches D3 Feed switch E1, E2, Ei Power storage unit (multiple power storage elements connected in parallel)
F1, F2, Fi Bypass circuit J Charge switch K Electric power storage unit R1, R2, Ri Resistance S700, S900 to S901 First step S701 to S703, S902 to S904, S902 to S940 Second step S704 to S706, S905 to S907 Third Steps S908 to S910 Fourth step T1 First predetermined time T2 Second predetermined time X1, X2, Xi Bypass circuit

Claims (19)

In the charging system for charging the storage battery of the power receiving device via the power receiving terminal of the power receiving device from the power feeding terminal of the power receiving device, the power charged in the storage battery of the power feeding device by the supply from the external power source,
In the power feeding device,
A first power storage module composed of a high energy density power storage element having a large chargeable / dischargeable capacity;
A second power storage module including a high power density storage element having a large chargeable / dischargeable current per unit time or a power storage unit in which a plurality of power storage units configured by a plurality of the high power density storage elements connected in parallel are connected in series; ,
A first connection state in which the first power storage module is connected to an external power source and disconnected from the second power storage module; and a second connection state in which the first power storage module is connected to the second power storage module and disconnected from the external power source. A first switch that can be switched;
A control unit capable of control including switching of the first switch,
In the power receiving device,
A third power storage module including a high power density power storage element having a large chargeable / dischargeable current per unit time, or a power storage unit in which a plurality of power storage units composed of the high power density power storage elements connected in parallel are connected in series; ,
A fourth power storage module configured with a high energy density power storage element having a large chargeable / dischargeable capacity;
Switching between the third connection state in which the fourth power storage module is connected to the load and disconnected from the third power storage module, and the fourth connection state in which the fourth power storage module is connected to the third power storage module and disconnected from the load is performed. A possible second switch;
And a control unit capable of control including the second switch. The charging system according to claim 1,
The third power storage module includes:
A plurality of bypass circuits including a bypass switch that is connected in parallel for each power storage unit and the bypass path is turned on when the switch is turned ON;
A charging system comprising: a bypass control unit that controls the bypass switch based on a voltage value for each power storage unit. The charging system according to claim 2,
The third power storage module includes:
A power supply switch that is inserted in series in the input / output path of the power storage unit and that turns the input / output path ON / OFF;
The bypass control unit further has a function of controlling the power supply switch. The charging system according to any one of claims 1 to 3,
The first switch is
In addition to the first connection state and the second connection state,
A fifth connection state in which the second power storage module is connected to the external power source and disconnected from the first power storage module;
A state in which at least any two points of the contact point related to the first switch are conducted can be selected;
The second switch is
In addition to the third connection state and the fourth connection state,
A sixth connection state in which the third power storage module is connected to the load and disconnected from the fourth power storage module;
The charging system is capable of selecting a state in which at least any two points of the contact point related to the second switch are made conductive. The charging system according to any one of claims 1 to 4,
A power supply switch that is inserted in a power supply path between the second power storage module and the power supply terminal to turn the power supply path ON / OFF;
The controller is
When the first switch is in either the second connection state or the fourth connection state, the power supply switch is turned off;
The charging system, wherein the power switch is turned on when the first switch is neither the second connection state nor the fourth connection state. The charging system according to claim 4,
The controller is
Turning off the power supply switch at any of the second connection state, the fifth connection state, the fourth connection state, and the sixth connection state;
The charging system, wherein the power supply switch is turned on when none of the second connection state, the fifth connection state, the fourth connection state, and the sixth connection state. The charging system according to any one of claims 1 to 6,
The external power supply includes a solar battery or an AC power supply. The charging system according to any one of claims 1 to 7,
The high power density storage element is:
A charging system comprising a lithium ion capacitor or an electric double layer capacitor. The charging system according to any one of claims 1 to 8,
The charging system, wherein the power receiving device is included in a moving body and supplies driving power to the moving body. The charging system according to claim 1, wherein
2. The charging system according to claim 1, wherein the total amount of power when the power storage unit included in the second power storage module is fully charged is greater than the total amount of power when the power storage unit included in the third power storage module is fully charged. A charging method using the charging system according to any one of claims 1 to 10,
A charging method, comprising: a first charging step of charging the third power storage module with the power stored in the second power storage module. A charging method using the charging system according to any one of claims 2 to 10,
In the first charging step of charging the third power storage module with the power stored in the second power storage module,
A first step of charging all of the power storage units by turning off all bypass switches until at least one voltage value of the plurality of power storage units is equal to or higher than a charging target voltage;
A second step of turning on the bypass switch of the bypass circuit corresponding to the power storage unit that has reached the target charging voltage to bypass the current flowing through the power storage unit to the bypass circuit;
When the voltage value of the power storage unit whose current has been bypassed by the second step is equal to or lower than the charging restart voltage, the bypass switch corresponding to the power storage unit is turned OFF, and the current that has been bypassed is stored in the power storage unit. And a third step of flowing in the charging method. The charging method according to claim 12, wherein
Including a fourth step of turning off the input / output path of the power storage unit to interrupt or complete charging after the first predetermined time has elapsed since the voltage value of at least one power storage unit has reached or exceeded the charging target voltage. Charging method characterized by. The charging method according to claim 12 or 13,
The first charging step includes
The second step and the third step are repeatedly executed,
In the second step,
A charging method comprising: turning on a bypass switch corresponding to a power storage unit that has passed a second predetermined time after reaching a charge target voltage, and diverting a current flowing through the power storage unit to the bypass circuit. The charging method according to any one of claims 11 to 14,
Charging including a second charging step of charging the second power storage module with power stored in the first power storage module in a state where the power supply terminal and the power receiving terminal are not electrically connected. Method. The charging method according to any one of claims 11 to 15,
Charging characterized by including a third charging step of charging the fourth power storage module with the power stored in the third power storage module in a state where the power supply terminal and the power receiving terminal are not electrically connected. Method. The charging method according to any one of claims 11 to 16,
A charging method comprising a fourth charging step of charging the first power storage module with electric power of the external power source. The charging method according to any one of claims 11 to 17,
A charging method comprising performing a fourth charging step of charging the first power storage module with electric power of the external power source simultaneously with the first charging step. The charging method according to any one of claims 11 to 18,
A charging method comprising: a fifth charging step of charging the second power storage module with electric power of the external power source in a state where the power feeding terminal and the power receiving terminal are not electrically connected.

Images