JPWO2013093963A1 - Charger - Google Patents

Abstract

  In a battery charging device including a circuit block 8-1 that has a power factor improving function and converts the voltage of an AC power source into an arbitrary voltage or current and outputs the voltage, and a circuit block 8-2, both circuit blocks 8-1 , 8-2 is provided with a connection switching unit 6 for switching the input side to either serial or parallel connection, and when the connection switching unit 6 is operated so that the voltage of the AC power supply 2 is less than a predetermined voltage value, The input sides of the blocks 8-1 and 8-2 are connected in parallel, and when the voltage of the AC power supply 2 is equal to or higher than a predetermined voltage value, the input sides of the circuit blocks 8-1 and 8-2 are connected in series.

Description

  The present invention relates to a charging device that is mounted on an electric vehicle or the like and charges an in-vehicle power battery.

In the trend of reducing global warming gas emissions, low carbon dioxide emissions have been accepted, demand for electric vehicles has increased, and diffusion has accelerated. A power (on-vehicle) battery mounted on the electric vehicle is charged by an external AC power source using a charging device.
The charging device includes a power factor correction (PFC) circuit composed of a coil (reactor) and a switching element for efficiently taking in electric power from an AC power source, an AC power source and an in-vehicle power battery. A PWM (Pulse Width Modulation) controlled DC / DC converter circuit composed of an insulating transformer and a switching element for insulating the circuit is used.
The power factor correction circuit and the DC / DC converter circuit are configured to cope with various AC power supply environments encountered by electric vehicles and charging or discharging states of in-vehicle power batteries, including 100 Vrms and 200 Vrms systems. However, in a wide range of AC power supply voltages, even if the vehicle-mounted power battery varies from about 80 Vdc to about 400 Vdc, it can cope.

In the above-described charging device using the PWM control DC / DC converter, for example, when a transformer having a large turns ratio is used to charge a high voltage battery from a low voltage AC power supply voltage, a high voltage AC power supply is used. When charging a low-voltage battery from a voltage, an operation of applying a rectangular wave having a narrow duty to a transformer for a DC / DC converter, and conversely, when charging a high-voltage battery from a low-voltage AC power supply voltage The operation of applying a rectangular wave with a wide duty to the transformer for the DC / DC converter is performed.
Thus, a transformer for a DC / DC converter must be applied with a rectangular wave of Duty that varies from a narrow width to a wide width. In a single circuit configuration, the efficiency is high depending on the AC power supply voltage. The difference from the case where efficiency is low tends to be obvious.
In other words, for example, if the AC power supply voltage range is set to be high in the middle of the range, the AC power supply voltage is low or the AC power supply voltage is high. It is difficult to ensure uniform high efficiency with respect to voltage.

As a conventional technique for maintaining high efficiency even when the input AC power supply voltage fluctuates, a technique for switching an operating circuit corresponding to the AC power supply voltage has been proposed.
For example, Patent Document 1 describes a power supply device that uses a transformer having two primary windings and two transistors that apply a rectangular wave to the transformer. In this device, when the AC power supply voltage is 100 Vrms, the transistor is connected to the transformer so as to perform a push-pull operation. When the AC power supply voltage is 200 Vrms, the transistor is connected to the transformer so as to perform a half-bridge operation. Is switched to perform a suitable operation for both voltages.

Patent Document 2 describes a switching power supply circuit using two transformers and a half-bridge type switching element that applies a rectangular wave to each transformer.
In this circuit, when the AC power supply voltage is 100 Vrms, rectangular waves are applied to the two transformers by the respective switching elements, and the outputs of both transformers are connected in parallel to obtain a set of DC outputs. When the voltage is 200 Vrms, the operation of the switching element on one of the transformers is stopped, and a direct current output is obtained only by the output of the other transformer that operates, so that a suitable operation is performed for both voltages. .
Switching between the two is performed by a transistor that operates in response to the AC power supply voltage, and when the AC power supply voltage is 200 Vrms, the operation signal input to one of the transformer side switching elements is short-circuited, and the switching element operates. It is done by stopping.

JP 2000-209858 A JP 2004-112926 A

  In the conventional techniques cited in both Patent Documents 1 and 2, in a circuit configuration for rectifying an AC power supply, double voltage rectification is performed when the AC power supply voltage is 100 Vrms, and full-wave when the AC power supply voltage is 200 Vrms. What performs rectification is described. In a configuration using such a voltage doubler rectifier circuit, power for half a cycle of alternating current must be stored in a capacitor, and a large capacitor with a corresponding capacity is required for a high-power device. It is not preferable for small equipment due to cost.

  Moreover, although the invention which concerns on patent documents 1 and 2 is equipped with the structure which switches an input circuit with an alternating current power supply voltage, neither is related with the charging device which charges the battery which stores big electric power. For this reason, there is no consideration for securing a high power factor, and naturally there is no power factor correction circuit. Furthermore, since a general-purpose element having a low rated voltage is used as a switching element or a rectifier diode, there is no idea regarding a configuration in which outputs are connected in series.

In a charging device that charges a large-capacity battery from an AC power supply, it is common to combine a power factor correction circuit and a DC / DC converter circuit without using a simple AC / DC converter in order to perform charging with high efficiency. Is.
In particular, in a charging device for charging a large-capacity battery for an electric vehicle, the environment and storage amount of the AC power supply when charging at the destination of the vehicle as a component used in the power factor correction circuit or the DC / DC converter circuit Therefore, it is necessary to select a rated component that has a characteristic corresponding to a battery voltage that varies depending on the power supply, and that can sufficiently handle even a combination of an AC power supply voltage and an output voltage that are in bad condition.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a charging device that can charge a battery that stores large power with high efficiency with a simple configuration.

  The charging device according to the present invention includes a rectifying unit that rectifies an AC power source into a DC output, a plurality of circuit blocks that have a power factor improving function and convert the voltage of the AC power source into an arbitrary voltage or current, and A charging device for charging a power battery mounted on a vehicle with a set of electric power obtained by connecting the output sides of a plurality of circuit blocks in series. , With a connection switching unit that switches the input side of multiple circuit blocks to either serial or parallel connection, and connects the input sides of multiple circuit blocks in parallel when the voltage of the AC power supply is less than a predetermined voltage value When the voltage of the AC power source is equal to or higher than a predetermined voltage value, the input sides of the plurality of circuit blocks are connected in series.

  According to the present invention, there is an effect that a battery that stores large power can be charged with high efficiency with a simple configuration.

It is a figure which shows the structure of the charging device which concerns on Embodiment 1 of this invention. It is a figure which shows another structural example of the charging device which concerns on Embodiment 1. FIG. It is a figure which shows the structure of the charging device which concerns on Embodiment 2 of this invention. FIG. 6 is a diagram illustrating a configuration example of a circuit that drives an FET of a control unit according to a second embodiment. It is a figure which shows the structure of the charging device which concerns on Embodiment 3 of this invention. It is a figure which shows another structural example of the charging device which concerns on Embodiment 3. FIG. It is a figure which shows the structure of the charging device which concerns on Embodiment 4 of this invention.

Hereinafter, in order to describe the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
1 is a diagram showing a configuration of a charging apparatus according to Embodiment 1 of the present invention. A charging device 1 shown in FIG. 1 is a device for charging a battery 3 for an electric vehicle from an AC power source 2, and includes a power rectification unit 5, a connection switching unit 6, PFC (Power Factor Correction) / DC / DC. A converter unit 7 and a control unit 9 are provided. The battery 3 for an electric vehicle is connected to a high voltage load 4 such as a power motor for the electric vehicle.

The power rectifier 5 includes diodes 5-1 to 5-4 connected for full-wave rectification.
Each anode terminal of the diodes 5-1 and 5-2 becomes a low potential side output, is connected to the source terminal of each FET (field effect transistor) of the circuit block 8-2, and is connected to the circuit block 8- via the switch SW2. 1 is connected to the source terminal of each FET.
Further, each cathode terminal of the diodes 5-3 and 5-4 becomes a high potential side output, is connected to one end of the coil of the circuit block 8-1 (terminal not connected to the FET), and is connected to the circuit via the switch SW1. It is connected to one end of the coil of block 8-2.
Further, one output terminal of the AC power source 2 is connected to the connection point of the diodes 5-1 and 5-3, and the other output terminal of the AC power source 2 is connected to the connection point of the diodes 5-2 and 5-4. Yes.

  The connection switching unit 6 includes switches SW1 and SW2 and a diode D1 that are turned on / off according to a connection switching signal from the control unit 9. The switch SW1 turns on / off the connection between each cathode terminal of the diodes 5-3 and 5-4 and one end of the coil of the PFC section of the circuit block 8-2. The switch SW2 turns on / off the connection between the anode terminals of the diodes 5-1 and 5-2 and the source terminals of the FETs of the PFC unit and the DC / DC converter unit of the circuit block 8-1. The diode D1 has a cathode terminal connected to a connection point between the switch SW1 and one end of the coil of the PFC unit of the circuit block 8-2. The switch D2 and the PFC unit and the DC / DC converter unit of the circuit block 8-1 are connected to each other. An anode terminal is connected to a connection point with the source terminal of each FET.

  The PFC / DC / DC converter unit 7 uses various AC power sources 2 such as a 100 Vrms system or a 200 Vrms system as a power source to generate a DC voltage for an electric vehicle (for power) that varies from about 80 Vdc to about 400 Vdc. In the example of FIG. 1, the PFC / DC / DC converter unit 7 is composed of two circuit blocks 8-1 and 8-2, and the circuit block 8-1 and 8-2 are connected to the battery 3 on the output side. Are connected in series, and the input side is connected to the AC power source 2 via the power source rectifier 5 by switching on and off the switches SW1 and SW2 so that the parallel connection and the series connection are switched. That is, when both the switches SW1 and SW2 are turned on, the input sides of the circuit blocks 8-1 and 8-2 are connected in parallel, and when both the switches SW1 and SW2 are turned off, the circuit blocks 8-1 and 8-2 are connected via the diode D1. The input side of 8-2 is connected in series. The PFC / DC / DC converter unit 7 may be configured using three or more circuit blocks.

  The circuit blocks 8-1 and 8-2 include a PFC (power factor correction) unit and a DC / DC converter unit. The PFC unit is composed of a coil, an FET, a diode, and a capacitor. The FET intermittently passes the current flowing through the coil according to the drive signal of the control unit 9, and the magnetic energy stored in the coil and the core while the FET is on, It functions as a boosting power source that turns off and discharges the FET. This PFC unit increases the power factor by outputting the corresponding power even at the timing when the power supply voltage decreases during one AC cycle.

  The DC / DC converter unit includes a forward transformer, a bridge unit including four FETs connected in an H shape, a rectification unit including four rectifier diodes, a coil, and a smoothing capacitor. Each FET in the bridge unit is turned on / off by a drive signal from the control unit 9 to generate a substantially rectangular wave, and applies the substantially rectangular wave to the primary winding of the transformer. The rectifier is a full-wave rectifier circuit composed of four rectifier diodes, and rectifies a substantially rectangular wave generated in the secondary winding of the transformer. The current rectified by the rectification unit is smoothed by a smoothing coil and a smoothing capacitor, and a DC voltage is output.

  The control unit 9 outputs a drive signal for turning on and off the FET of the PFC unit and the FET of the bridge unit of the DC / DC converter unit. The control unit 9 also receives the power supply voltage that has been full-wave rectified by the power supply rectification unit 5 and outputs a connection switching signal for turning on and off the switches SW1 and SW2 of the connection switching unit 6 in accordance with the power supply voltage.

Next, the operation will be described.
The control unit 9 inputs the power supply voltage of the AC power supply 2 via the power supply rectification unit 5, compares the input voltage value with a predetermined voltage value, and the input voltage value (agreement with the power supply voltage value) is a predetermined voltage. If the value is equal to or greater than the value, a connection switching signal for turning off both the switches SW1 and SW2 is output to the connection switching unit 6. When the connection switching unit 6 receives this connection switching signal, both the switches SW1 and SW2 are turned off. As a result, when current flows through the diode D1, the input sides of the circuit blocks 8-1 and 8-2 are connected in series via the diode D1, and the battery 3 is charged from the PFC / DC / DC converter unit 7. A set of DC output is obtained as electric power.

  On the other hand, if the input voltage value (which agrees with the power supply voltage value) is less than the predetermined voltage value, the control unit 9 outputs to the connection switching unit 6 a connection switching signal that turns on both the switches SW1 and SW2. . When the connection switching unit 6 inputs this connection switching signal, both the switches SW1 and SW2 are turned on. As a result, a set of DC outputs is obtained as charging power for the battery 3 from the PFC / DC / DC converter unit 7 in which the input sides of the circuit blocks 8-1 and 8-2 are connected in parallel. At this time, a voltage is applied to the diode D1 in the reverse direction and no current flows.

  Here, if the predetermined voltage value is 160 Vrms, for example, the AC power supply 2 having a power supply voltage value equal to or higher than the predetermined voltage value is a 200 Vrms AC power supply. The AC power supply 2 having a power supply voltage value less than a predetermined voltage value is a 100 Vrms AC power supply.

The charging device according to Embodiment 1 may be configured as shown in FIG.
FIG. 2 is a diagram illustrating another configuration example of the charging apparatus according to the first embodiment. The PFC / DC / DC converter unit 7A of the charging device 1A shown in FIG. 2 is different from the circuit block shown in FIG. The circuit blocks 8A-1 and 8A-2 shown in FIG. 2 have a primary winding that also serves as a power factor improving coil, and a flyback that includes a secondary winding that insulates the AC power source 2 from the vehicle power source. Configured using an expression transformer.

The FETs of the circuit blocks 8A-1 and 8A-2 are switching elements for intermittently supplying current to the primary winding of the transformer. The rectifier diode rectifies the output current from the secondary winding of the transformer. The smoothing capacitor stores and smoothes the output current of the rectifier diode.
In the circuit block units 8A-1 and 8A-2, as shown in FIG. 2, a smoothing capacitor provided on the secondary winding side (output side) of each transformer is connected in series to the battery 3.

One terminal (terminal not connected to the FET) of the primary winding of the transformer of the circuit block 8A-1 is connected to one terminal of the power supply rectifier 5 and one terminal of the switch SW1, and the transformer The other terminal of the primary winding is connected to the drain terminal of the FET, and the source terminal of the FET is connected to the anode terminal of the diode D1 and one terminal of the switch SW2.
Further, one terminal (terminal not connected to the FET) of the primary winding of the transformer of the circuit block 8A-2 is connected to the cathode terminal of the diode D1 and the other terminal of the switch SW1, and 1 of the transformer. The other terminal of the next winding is connected to the drain terminal of the FET, and the source terminal of the FET is connected to the other terminal of the switch SW2 and the other terminal of the power supply rectifying unit 5.

If the power supply voltage value of the AC power supply 2 is equal to or higher than the predetermined voltage value, the control unit 9 operates the circuit switching units 8A-1 and 8A-2 so that both the switches SW1 and SW2 of the connection switching unit 6 are turned off. Are connected in series via a diode D1. Thus, a set of direct current outputs is obtained as the charging power of the battery 3 from the PFC / DC / DC converter unit 7A.
On the other hand, if the power supply voltage value of the AC power supply 2 is less than the predetermined voltage value, the control unit 9 operates the circuit switches 8A-1 and 8A so that both the switches SW1 and SW2 of the connection switching unit 6 are turned on. -2 input side connected in parallel. Thereby, a set of direct current outputs is obtained as the charging power of the battery 3 from the PFC / DC / DC converter section 7A.

  In the present invention, a DC / DC converter unit using a PFC unit and a forward type transformer or a coil for power factor improvement is used so that a high voltage is not applied to a switching element or a rectifier diode to be used due to a power source voltage of an AC power source. A plurality of circuit blocks constituted by a DC / DC converter unit using a flyback transformer that also serves as a power source, and a set of charging by connecting the secondary side components of the transformer of each circuit block in series Get the output.

  In this way, by connecting the secondary side constituent members in series, a general-purpose element having a low rated voltage can be used as a switching element or a rectifier diode to be used. Furthermore, since multiple circuit blocks are used, if the AC power supply voltage is low, these circuit blocks are connected in parallel, and if the AC power supply voltage is high, a configuration in which they are connected in series is realized. can do.

  By switching and connecting the input sides of a plurality of circuit blocks in parallel or in series with an AC power supply voltage, the turn ratio of the transformer to be used and the duty of the rectangular wave voltage applied to the primary side of this transformer It is possible to keep the efficiency high under various conditions for the input AC power supply voltage and the output charging voltage of the battery 3.

In order to maintain high efficiency, the transformer turns ratio is set to the number of turns for a specific power supply voltage and output voltage, and a substantially rectangular wave applied to the primary side of the transformer is applied during a period in which no voltage is applied. It is desirable to have a small waveform (a rectangular wave with a wide duty).
However, for example, in a configuration including one circuit block, in order to charge a 400 Vdc battery from a power supply voltage of 100 Vrms, it is necessary to use a transformer that secures a boost of about three times (400 / 100√2). Yes, in this configuration, when charging a battery of 80 Vdc with a power supply voltage of 200 Vrms, the duty of the applied rectangular wave should be approximately 1/7 [(80/200) × (100√2 / 400)]. I must. As described above, in the configuration including only one circuit block, the period during which no voltage is applied is inevitably expanded (the duty width of the rectangular wave is narrowed), and thus the efficiency cannot be denied.

As described above, when all the AC power supply voltage ranges are handled by one circuit configuration, the difference between when the efficiency is high and when the efficiency is low is easily manifested by the AC power supply voltage. It has been difficult to ensure high efficiency.
On the other hand, in the charging apparatus according to the present invention, high efficiency is ensured in a wide range of AC power supply voltages by switching and connecting the input sides of a plurality of circuit blocks having high efficiency but a narrow corresponding voltage in parallel or in series. be able to.

In the configuration of FIGS. 1 and 2, when the input sides of two circuit blocks are connected and operated in series, the operation of the two circuit blocks is unbalanced and both output different powers. In order to prevent this, the control unit 9 inputs the respective voltages output by the two, and the PFC unit so that the outputs of both are equal based on the values of these input voltages (agreeing with the output voltage of the circuit block) Or you may control each FET of a DC / DC converter part.
For example, the control unit 9 feeds back the voltage of the capacitor of each PFC unit of two circuit blocks or the voltage of the smoothing capacitor of each DC / DC converter unit, so that the PFC unit or the DC / DC converter unit Control each FET.

1 and 2, when the input sides of two circuit blocks are connected in parallel and operated, if the FETs of each circuit block are operated simultaneously, the influence of ripples superimposed on the wiring is affected. Therefore, in order to reduce the ripple and reduce the noise, the control unit 9 controls the output timing of the drive signal to shift the operation phases of the FETs of the respective circuit blocks.
When the input sides of the two circuit blocks are connected in series, the FETs of the circuit blocks are also connected in series. Therefore, if the FETs are not operated simultaneously, a current is supplied with a desired duty. Therefore, the control unit 9 controls the output timing of the drive signal to operate the FETs of the respective circuit blocks in the same phase.

In the above description, a configuration in which all control is performed by one control unit 9 is shown, but a control unit may be provided for each circuit block, and each control may be shared.
The switches SW1 and SW2 for switching the connection on the input side of the two circuit blocks are relay contacts, for example, and are operated by energizing or stopping the current to the operation coil of the relay by the AC power supply voltage.

  Furthermore, when the voltage value for switching the connection on the input side of a plurality of circuit blocks is set to one point, when the AC power supply voltage fluctuates up and down across the voltage value, a hunting operation that repeatedly switches between series connection and parallel connection is performed. 1 and 2, the first voltage for switching the input sides of the two circuit blocks from the parallel connection to the series connection is used as the predetermined voltage value for turning on and off the switches SW1 and SW2. A value and a second voltage value that switches from series connection to parallel connection are set, and the first voltage value is higher than the second voltage value. That is, a hysteresis is provided in the voltage value for switching the connection on the input side of the plurality of circuit blocks, and the control unit 9 allows the AC power supply voltage to be equal to or higher than the second voltage value when the input sides of the two circuit blocks are connected in parallel. Even if it is less than the first voltage value, the connection is maintained, and when the AC power supply voltage exceeds the first voltage value, the input side of the two circuit blocks is switched from the parallel connection to the series connection. Control. In addition, when the input sides of the two circuit blocks are connected in series, the control unit 9 maintains the connection if the AC power supply voltage is less than the first voltage value and is greater than or equal to the second voltage value. Then, when the AC power supply voltage becomes less than the second voltage value, the input side of the two circuit blocks is controlled to be switched from the serial connection to the parallel connection.

By setting the voltage value for switching from parallel connection to series connection and the voltage value for switching from series connection to parallel connection separately, and providing hysteresis for the voltage value to be switched, the occurrence of hunting operations can be avoided and the behavior stabilized. Can be realized.
The first AC voltage value for switching the input side of the plurality of circuit blocks from parallel connection to series connection is, for example, 170 Vrms, and the second AC voltage value for switching from series connection to parallel connection is, for example, 150 Vrms.

As described above, according to the first embodiment, the power source rectifying unit 5 that rectifies the AC power source 2 into a DC output and the power factor improving function are provided to convert the voltage of the AC power source into an arbitrary voltage or current. Circuit blocks 8-1 and 8-2, and a control unit 9 for controlling the operation of the circuit blocks 8-1 and 8-2, and the output sides of the circuit blocks 8-1 and 8-2 are connected in series. A charging device 1 for charging a power battery 3 mounted on a vehicle with a set of charging power obtained by connection, wherein the input side of the circuit blocks 8-1 and 8-2 is either serial or parallel The connection switching unit 6 for switching to the connection is controlled. When the voltage of the AC power supply 2 is less than a predetermined voltage value by controlling the connection switching unit 6, the input sides of the circuit blocks 8-1 and 8-2 are arranged in parallel. When connected and the voltage of the AC power supply 2 is equal to or higher than a predetermined voltage value, the circuit block 8- And it connects the input side of the 8-2 in series.
With this configuration, it is possible to use a transformer with a suitable turns ratio or a coil with a suitable inductance for a wide range of AC power supply voltages.
Also, a suitable duty rectangular wave can be applied to the transformer, and a highly efficient charging device can be configured.

  Further, according to the first embodiment, the circuit block is configured by the PFC unit (power factor correction circuit) and the forward type DC / DC converter unit, or is configured by the flyback type DC / DC converter unit. To do. For example, in the case of a circuit configuration that emphasizes efficiency, a circuit block is configured by a PFC unit and a forward type DC / DC converter unit, and in the case where importance is placed on size and cost, a circuit is configured by a flyback type DC / DC converter unit. By configuring the block, it is possible to realize a charging device with suitable specifications according to the purpose.

Further, according to the first embodiment, the predetermined voltage value is a first voltage value for switching the input sides of the circuit blocks 8-1 and 8-2 in series and a value lower than the first voltage value. When the control unit 9 is configured to connect the input sides of the circuit blocks 8-1 and 8-2 in parallel, and the control unit 9 is connected in parallel to the input sides of the circuit blocks 8-1 and 8-2, Even if the voltage of the AC power supply 2 is equal to or higher than the second voltage value, the connection is maintained if the voltage is lower than the first voltage value. When the voltage of the AC power supply 2 becomes equal to or higher than the first voltage value, the circuit block 8- When the input side of 1 and 8-2 is switched from parallel connection to series connection and the input side of the circuit blocks 8-1 and 8-2 is connected in series, the voltage of the AC power supply 2 is the first voltage. Even if it is less than the value, if it is greater than or equal to the second voltage value, the connection is maintained and If less than the second voltage value, and controls to switch the input side of the circuit blocks 8-1 and 8-2 from the series connection to parallel connection.
By doing in this way, generation | occurrence | production of the hunting operation | movement which repeats switching of a serial connection and a parallel connection is avoided, and the charging device with the stable behavior is realizable.

  Furthermore, according to the first embodiment, when the control unit 9 is connected in parallel on the input side of the circuit blocks 8-1 and 8-2, the control unit 9 changes the operation phases of the circuit blocks 8-1 and 8-2. When the circuit blocks 8-1 and 8-2 are connected in series, the circuit blocks 8-1 and 8-2 are operated in the same phase. In this way, when the input sides of the circuit blocks 8-1 and 8-2 are connected in parallel, the operation phases of the circuit blocks 8-1 and 8-2 are shifted from each other to operate the wiring. The superimposed ripple can be reduced, noise can be reduced, and when the input sides of the circuit blocks 8-1 and 8-2 are connected in series, a charging device that can be operated at a desired duty can be realized.

Embodiment 2. FIG.
FIG. 3 is a diagram showing a configuration of a charging apparatus according to Embodiment 2 of the present invention. The charging device 1B shown in FIG. 3 includes a connection switching unit 6A in which the switch SW1 of the connection switching unit 6 in the configuration of FIG. 2 of the first embodiment is a switching element (FET1) and the switch SW2 is a switching element (FET2). It is substituted. In FIG. 3, the same components as those in FIG.

  The control unit 9 inputs the power supply voltage of the AC power supply 2 via the power supply rectification unit 5, compares the input voltage value with a predetermined voltage value, and the input voltage value (agreement with the power supply voltage value) is a predetermined voltage. If it is equal to or greater than the value (for example, when AC power supply 2 is a 200 Vrms AC power supply), a connection switching signal for turning off both FET1 and FET2 is output to connection switching unit 6A. When this connection switching signal is input, the connection switching unit 6A turns off both FET1 and FET2. As a result, when current flows through the diode D1, the input sides of the circuit blocks 8A-1 and 8A-2 are connected in series via the diode D1, and the battery 3 is charged from the PFC / DC / DC converter unit 7A. A set of DC output is obtained as electric power.

  On the other hand, if the input voltage value (agreement with the power supply voltage value) is less than a predetermined voltage value (for example, when the AC power supply 2 is a 100 Vrms type AC power supply), the control unit 9 controls the connection switching unit 6A. A connection switching signal for turning on both FET1 and FET2 is output. When the connection switching unit 6A receives this connection switching signal, both the FET1 and FET2 are turned on. As a result, a set of DC outputs is obtained as charging power for the battery 3 from the PFC / DC / DC converter unit 7A in which the input sides of the circuit blocks 8A-1 and 8A-2 are connected in parallel. At this time, a voltage is applied to the diode D1 in the reverse direction and no current flows.

  In the configuration of FIG. 3, when the input sides of the two circuit blocks are connected in series and operated, the operation of the two circuit blocks is unbalanced and the two do not output different power. As described above, the control unit 9 may input the respective voltages output from the both, and control the FET of the DC / DC converter unit so that the outputs of both are equal based on these input voltage values. For example, the control unit 9 feeds back the voltages (respective output voltages) of the smoothing capacitors of the DC / DC converter units of the two circuit blocks to control the FETs of the DC / DC converter unit, Both output voltages are made equal.

In the configuration of FIG. 3, when the input sides of two circuit blocks are connected in parallel and operated, if the FETs of each circuit block are operated simultaneously, the influence of ripples superimposed on the wiring increases. In order to reduce the ripple and reduce the noise, the control unit 9 controls the output timing of the drive signal to shift the operation phases of the FETs in the respective circuit blocks.
When the input sides of the two circuit blocks are connected in series, the FETs of the circuit blocks are also connected in series. Therefore, if the FETs are not operated simultaneously, a current is supplied with a desired duty. Therefore, the control unit 9 controls the output timing of the drive signal to operate the FETs of the respective circuit blocks in the same phase.

Moreover, although the structure which performs all the control by the one control part 9 was shown in the said description, a control part may be provided for each circuit block, and each control may be shared.
Further, in the configuration of FIG. 3, as in the first embodiment, the control unit 9 connects the input sides of the two circuit blocks in parallel as the predetermined voltage value for turning on and off the FET1 and FET2 of the connection switching unit 6A. A first voltage value that switches from serial connection to serial connection and a second voltage value that switches from serial connection to parallel connection are set, and the relationship between them is [(first voltage value> second voltage value)]. Good. For example, the first AC voltage value is 170 Vrms, and the second AC voltage value is 150 Vrms.
By doing in this way, generation | occurrence | production of a hunting operation | movement is avoided and the charging device with the stable behavior is realizable.

  In the above description, the switches SW1 and SW2 are replaced with FET1 and FET2, but an IGBT (Insulated Gate Bipolar Transistor) or a transistor may be used instead of the FET.

FIG. 4 is a diagram illustrating a configuration example of the connection switching FET drive circuit in the control unit 9 according to the second embodiment. Since the connection switching of the circuit block by the connection switching unit does not need to be performed at a high speed like the PFC or the DC / DC converter FET, a pulse in which the primary winding and the secondary winding are insulated as shown in FIG. Use a connection switching signal generated using a transformer. In this configuration, when turning on FET1 and FET2 of the connection switching unit, a rectangular wave is input to the primary side of the pulse transformer, and the rectangular wave generated on the secondary side of the pulse transformer is rectified by a diode. The generated voltage is applied to the gate terminals of FET1 and FET2 of the connection switching unit. As a matter of course, when the application of the rectangular wave to the primary side of the pulse transformer is stopped, the gate terminal voltages of the FET1 and FET2 of the connection switching unit are lowered and the FET1 and FET2 of the connection switching unit are turned off.
As described above, by using the pulse transformer, the control unit 9 can turn on and off the FET1 and FET2 of the connection switching unit having different operating potentials, and the input sides of the circuit blocks 8A-1 and 8A-2 can be controlled. It is possible to arbitrarily switch to serial connection or parallel connection.

  As described above, according to the second embodiment, the connection switching unit 6A connects the input sides of the circuit blocks 8A-1 and 8A-2 either in series or in parallel with a semiconductor switching element such as an FET. Therefore, a long-life and highly reliable charging device can be realized as compared with a mechanical switch such as a relay whose contact life is an issue. As in the first embodiment, a transformer with a suitable turns ratio and a coil with a suitable inductance can be used for a wide range of AC power supply voltages. Also, a suitable duty rectangular wave can be applied to the transformer, and a highly efficient charging device can be configured.

Embodiment 3 FIG.
FIG. 5 shows a configuration of the charging apparatus according to Embodiment 3 of the present invention. A charging device 1C shown in FIG. 5 uses the switch SW1 of the connection switching unit 6 in the configuration of FIG. 2 of the first embodiment as a switching element (FET1), the switch SW2 as a switching element (FET2), and the diode D1 as a switching element. The connection switching unit 6B is replaced with (FET3). In FIG. 5, the same components as those in FIG.

  The control unit 9 inputs the power supply voltage of the AC power supply 2 via the power supply rectification unit 5, compares the input voltage value with a predetermined voltage value, and the input voltage value (agreement with the power supply voltage value) is a predetermined voltage. If it is equal to or greater than the value (for example, when the AC power supply 2 is a 200 Vrms AC power supply), both the FET1 and FET2 are turned off and a connection switching signal for turning on the FET3 is output to the connection switching unit 6B. When this connection switching signal is input, the connection switching unit 6B turns off both FET1 and FET2 and turns on FET3. As a result, the input sides of the circuit blocks 8A-1 and 8A-2 are connected in series via the FET 3, and a current is passed through the FET 3, so that a set of charging power for the battery 3 from the PFC / DC / DC converter unit 7A is set. DC output is obtained.

  On the other hand, if the input voltage value (agreement with the power supply voltage value) is less than a predetermined voltage value (for example, when the AC power supply 2 is a 100 Vrms type AC power supply), the control unit 9 will A connection switching signal for turning on both FET1 and FET2 and turning off FET3 is output. When this connection switching signal is input, the connection switching unit 6B turns on both FET1 and FET2 and turns off FET3. As a result, a set of DC outputs is obtained as charging power for the battery 3 from the PFC / DC / DC converter unit 7A in which the input sides of the circuit blocks 8A-1 and 8A-2 are connected in parallel.

Further, the charging apparatus according to Embodiment 3 may be configured as shown in FIG.
FIG. 6 is a diagram illustrating another configuration example of the charging apparatus according to Embodiment 3. In FIG. In the power rectifier 5A of the charging device 1C shown in FIG. 6, the diodes 5-1 to 5-4 of the power rectifier 5 shown in FIG. 5 are replaced with FETs 13-1 to 13-4. The phase input unit of the control unit 9 is a part that controls the on / off operation of the switching element of the power supply rectification unit 5A, and inputs both voltages of the AC power supply 2 via the resistors R1 and R2, respectively, and the resistor R1 , R2 and comparators 10a and 10b for comparing the AC power supply voltage inputted through R2 and the comparison DC voltage of the comparison power supply 10c, respectively.

  Pulse transformers 14a and 14b are provided as drivers for driving the FETs 13-3 and 13-4. The pulse transformers 14a and 14b output a drive signal corresponding to the outputs of the comparators 10a and 10b to the gate terminals of the FETs 13-3 and 13-4 to perform an on / off operation.

  The comparator 10a outputs a high-level or low-level voltage by comparing the AC power supply voltage input via the resistor R1 and the comparison DC voltage of the comparison power supply 10c, and the comparator 10b passes through the resistor R2. A high level voltage or a low level voltage is output by comparing the AC power supply voltage inputted in comparison with the comparative DC voltage.

For example, when the AC power supply voltage on the resistor R1 side of the AC power supply 2 becomes equal to or higher than the comparative DC voltage and current flows in the forward direction of the diode of the FET 13-2, the output of the comparator 10a becomes high and the FET 13- 2 is turned on. Further, when the AC power supply voltage on the resistor R2 side of the AC power supply 2 becomes equal to or higher than the comparative DC voltage, and the current flows in the forward direction of the diode of the FET 13-1, the output of the comparator 10b becomes a high level, and the FET 13 Turn on -1.
Thus, the low-potential side diode (corresponding to the diodes 5-1 and 5-2) that flows current from the low-potential side output to the AC power supply 2 is short-circuited in synchronization with the phase of the AC power supply voltage of the AC power supply 2 Thus, synchronous rectification with less loss can be performed.
As described above, the control unit 9 controls (synchronous rectification) the on / off operation of the FETs 13-1 and 13-2 in synchronization with the phase of the AC power supply voltage of the AC power supply 2. It is possible to reduce the loss due to the forward voltage drop that has occurred in the diodes 5-1 and 5-2 on the potential side.

Further, the pulse transformers 14a and 14b output control signals corresponding to the outputs of the comparators 10a and 10b to the gate terminals of the FETs 13-3 and 13-4 to turn them on / off.
That is, when the AC power supply voltage on the resistance R1 side of the AC power supply 2 becomes equal to or higher than the comparison DC voltage and current flows in the forward direction of the diode of the FET 13-3, the output of the comparator 10a becomes high level. Accordingly, the voltage on the secondary side of the pulse transformer 14a rises to turn on the FET 13-3.
Further, when the AC power supply voltage on the resistor R2 side of the AC power supply 2 becomes equal to or higher than the comparative DC voltage and current flows in the forward direction of the diode of the FET 13-4, the output of the comparator 10b becomes high level. Accordingly, the voltage on the secondary side of the pulse transformer 14b rises to turn on the FET 13-4.
With this configuration, it is possible to further reduce the loss due to the forward voltage drop that occurs in the high-potential side diode (corresponding to the diodes 5-3 and 5-4).

Note that FETs with a diode function or a parasitic diode, such as FETs 13-1 to 13-4 in which diodes are connected in parallel, may be used, or an IGBT with a freewheeling diode may be used. The effect is obtained.
Further, for driving the high potential side FETs 13-3, 13-4 or IGBT, it is also possible to use a level shift circuit or an insulated driver circuit having another configuration in addition to the pulse transformer.

6 shows a circuit configuration using the comparators 10a and 10b as the phase input unit in the control unit 9. However, other circuit configurations or a digital circuit using a CPU may be used.
For example, the CPU takes in the AC power supply voltage of the AC power supply 2 via the A / D converter, and controls the on / off operation of the switching elements such as FETs 13-1 to 13-4 at an appropriate timing synchronized with the phase of the AC power supply 2. You can also
That is, the control unit 9 is configured to turn on (conduct) the switching element when current flows in the diode function or in the forward direction of the diode, and the power supply rectification unit and the connection switching unit are synchronized with the input AC power supply. Operate (rectify in synchronization with AC power supply).

  The circuit configuration of the control unit 9 using the comparators 10a and 10b or the CPU of the phase input unit can use the low potential side output of the DC power source obtained by rectifying the AC power source voltage of the AC power source 2 as a common potential. For this reason, it is possible to control the on / off operation of the switching element of the circuit block unit and the switching element for synchronous rectification with a simple circuit.

  In the above description, the diode of the power supply rectifying unit is replaced with a switching element having a diode function or a switching element having a parasitic diode or a switching element in which a diode is connected in parallel. Alternatively, the configuration may be replaced.

As described above, the power loss due to the diode is reduced by short-circuiting the forward voltage drop (for example, about 0.7 to 1 V) of the diode in the power supply rectification unit and the connection switching unit with the switching element connected in parallel. Thus, a highly efficient charging device can be configured.
For example, if the energizing current is 10 A, if a diode with a forward voltage drop of 1 V is used for the power rectifier and the connection switching unit, the power loss in the power rectifying unit and the connection switching unit will be 10 W. Can be reduced to 1 W by using a switching element of 10 mΩ.

  In the configurations of FIGS. 5 and 6, when the input sides of the two circuit blocks are connected in series and operated, the operation of the two circuit blocks is unbalanced and both output different powers. In order to prevent this, the control unit 9 inputs the respective voltages output by both, and controls the FET of the DC / DC converter unit so that the outputs of both are equal based on these input voltage values. Also good. For example, the control unit 9 feeds back the voltages (respective output voltages) of the smoothing capacitors of the DC / DC converter units of the two circuit blocks to control the FETs of the DC / DC converter unit, Both output voltages are made equal.

5 and 6, when the input sides of two circuit blocks are connected in parallel and operated, if the FETs of each circuit block are operated simultaneously, the influence of ripples superimposed on the wiring is affected. Therefore, in order to reduce the ripple and reduce the noise, the control unit 9 controls the output timing of the drive signal to shift the operation phases of the FETs of the respective circuit blocks.
When the input sides of the two circuit blocks are connected in series, the FETs of the circuit blocks are also connected in series. Therefore, if the FETs are not operated simultaneously, a current is supplied with a desired duty. Therefore, the control unit 9 controls the output timing of the drive signal to operate the FETs of the respective circuit blocks in the same phase.

In the above description, a configuration in which all control is performed by one control unit 9 is shown, but a control unit may be provided for each circuit block, and each control may be shared.
Further, in the configuration of FIG. 5 and FIG. 6, as in the first embodiment, the control unit 9 sets the predetermined voltage values for turning on / off the FET1, FET2, and FET3 of the connection switching unit 6B as two circuit blocks. The first voltage value for switching the input side from the parallel connection to the serial connection and the second voltage value for switching from the serial connection to the parallel connection are set, and the relationship between them is [(first voltage value> second voltage Value)]. For example, the first AC voltage value is 170 Vrms, and the second AC voltage value is 150 Vrms. By doing in this way, generation | occurrence | production of a hunting operation | movement is avoided and the charging device with the stable behavior is realizable.

Further, as in the second embodiment, FET1, FET2, and FET3 may be replaced with IGBTs or transistors other than FETs.
Similarly to the second embodiment, a drive signal to be applied to the gate terminals of the FET1, FET2, and FET3 of the connection switching unit is input to the primary side of the pulse transformer in the control unit 9, and this transformer is input. You may generate | occur | produce by rectifying | straightening the rectangular wave which generate | occur | produced on the secondary side. Note that the drive signal applied to the gate terminal of the FET 3 is a signal obtained by inverting the drive signals of the FET 1 and FET 2. With the above configuration, a long-life and highly reliable charging device can be configured by using a semiconductor switch instead of a relay having a contact life.

  As described above, according to the third embodiment, the diodes constituting the power supply rectifying unit 5A and the connection switching unit 6B are arranged in parallel with a switching element having a diode function, a switching element having a parasitic diode, or a diode. The control unit 9 makes the switching element conductive at the timing when the forward current flows through the diode or a portion corresponding to the diode, thereby controlling the forward voltage drop of the diode with the switching element. A short circuit occurs, power loss due to the diode can be reduced, and a highly efficient charging device can be realized. As in the first embodiment, a transformer with a suitable turns ratio and a coil with a suitable inductance can be used for a wide range of AC power supply voltages. Also, a suitable duty rectangular wave can be applied to the transformer, and a highly efficient charging device can be configured.

Embodiment 4 FIG.
FIG. 7 is a diagram showing a configuration of a charging apparatus according to Embodiment 4 of the present invention. The PFC / DC / DC converter unit 7B of the charging device 1D shown in FIG. 7 is composed of circuit blocks 8B-1 and 8B-2. Each of the circuit blocks 8B-1 and 8B-2 includes circuit block units 8B-1-1 to 8B-1-N and circuit block units 8B-2-1 to 8B-2-N (N is 2 or more). Any integer).
The circuit block units 8B-1-1 to 8B-1-N and the circuit block units 8B-2-1 to 8B-2-N are the same as the PFC unit and the forward type shown in FIG. An output smoothing capacitor for a circuit block consisting of a DC / DC converter unit, or an output of a circuit block consisting of a DC / DC converter unit using a flyback transformer also serving as a power factor improving coil shown in FIG. Each circuit is composed of small-capacity circuits using elements with low rated power while sharing a smoothing capacitor.
The configuration of the circuit block in FIG. 1 and the configuration of the circuit block in FIG. 2 are those in the case of N = 1 in the configuration in FIG.

The control unit 9 outputs a drive signal to each FET of each circuit block unit to control the on / off operation, thereby controlling the output voltage in each circuit block unit. At this time, by operating the FETs of the circuit block units 8B-1-1 to 8B-1-N and the circuit blocks 8B-2-1 to 8B-2-N at different phases, PFC / DC / DC The ripple superimposed on the input and output of the converter unit 7B can be reduced.
As a result, it is possible to realize a charging device with a small amount of ripples superimposed on the wiring and low noise. Further, since the ripple current input / output to / from the smoothing capacitor can be reduced, heat generation of the smoothing capacitor due to the ripple current is reduced, and deterioration of the smoothing capacitor can be suppressed.

In the configuration of FIG. 7, when the circuit block units 8B-1-1 to 8B-1-N and the input sides of the circuit block units 8B-2-1 to 8B-2-N are connected in parallel, In order to further reduce the ripple superimposed on the wiring and reduce the noise, the control unit 9 controls the output timing of the drive signal, and the circuit block units 8B-1-1 to 8B-1-N and the circuit block The operation phases of the individual FETs constituting the units 8B-2-1 to 8B-2-N are shifted from each other.
When the circuit block units 8B-1-1 to 8B-1-N and the input sides of the circuit block units 8B-2-1 to 8B-2-N are connected in series and operated, each circuit block unit Since each of the FETs constituting the circuit is also connected in series, current cannot be supplied with a desired duty unless the individual FETs connected in series are operated simultaneously. Therefore, the control unit 9 outputs the drive signal. By controlling the timing, each of the FETs connected in series of the circuit block units 8B-1-1 to 8B-1-N and the circuit block units 8B-2-1 to 8B-2-N is operated in the same phase. . At this time, if the operation phases of the individual FETs constituting each circuit block unit are shifted from each other, the ripple superimposed on the wiring can be reduced and the noise can be reduced as in the above-described parallel connection configuration.

  As described above, according to the fourth embodiment, a plurality of circuit block units 8B-1-1-8B having a power factor improving function and converting the voltage of the AC power source into an arbitrary voltage or current and outputting the voltage or current. −1-N and circuit block units 8B-2-1 to 8B-2-N (N is an arbitrary integer equal to or greater than 2), and each of the circuit blocks 8B-1 and 8B-2 includes a plurality of circuit blocks. Although configured by the units 8B-1-1 to 8B-1-N and the circuit block units 8B-2-1 to 8B-2-N, a part of the configuration is shared. By doing in this way, an element with a lower rated power can be used as an element used for each circuit block while suppressing an increase in the number of elements to be used.

  In the present invention, within the scope of the invention, any combination of each embodiment, any component of each embodiment can be modified, or any component can be omitted in each embodiment. .

  Since the charging device according to the present invention can charge a battery that stores large power with a simple configuration with high efficiency, the charging device is suitable for a charging device that is mounted on an electric vehicle and charges a driving battery.

  1, 1A to 1D charging device, 2 AC power supply, 3 battery, 4 load, 5, 5A power rectifier, 5-1 to 5-4 diode, 6, 6A, 6B connection switching unit, 7, 7A, 7B PFC DC / DC converter section, 8-1, 8-2, 8A-1, 8A-2, 8B-1, 8B-2 circuit block, 8B-1-1-1 to 8B-1-N, 8B-2-1 8B-2-N circuit block unit, 9 control unit, 10a, 10b comparator, 10c comparison power supply, 13-1 to 13-4 FET, 14a, 14b pulse transformer.

The charging device according to the present invention includes a rectifying unit that rectifies an AC power source into a DC output, a plurality of circuit blocks that have a power factor improving function and convert the voltage of the AC power source into an arbitrary voltage or current, and A charging device for charging a power battery mounted on a vehicle with a set of electric power obtained by connecting the output sides of a plurality of circuit blocks in series. , With a connection switching unit that switches the input side of multiple circuit blocks to either serial or parallel connection, and connects the input sides of multiple circuit blocks in parallel when the voltage of the AC power supply is less than a predetermined voltage value When the voltage of the AC power supply is equal to or higher than the predetermined voltage value, the input side of the plurality of circuit blocks is connected in series, and the input side of the plurality of circuit blocks is switched to either serial or parallel connection. value The first voltage value for switching the input side from parallel to series and the second voltage value lower than the first voltage value for switching the input side from series to parallel, and the input side of the circuit block is connected in parallel The switching elements of each circuit block operate with a phase shifted from each other, and when the input sides of the circuit blocks are connected in series, the switching elements of each circuit block operate with the same phase. Features.

Claims (7)

A rectifying unit that rectifies an AC power source into a DC output, a plurality of circuit blocks that have a power factor improvement function and convert the voltage of the AC power source into an arbitrary voltage or current, and control the operation of the circuit block A charging device for charging a power battery mounted on a vehicle with a set of electric power obtained by connecting the output sides of the plurality of circuit blocks in series,
A connection switching unit for switching the input side of the plurality of circuit blocks to either serial or parallel connection;
When the voltage of the AC power supply is less than a predetermined voltage value, connect the input side of the plurality of circuit blocks in parallel,
When the voltage of the AC power source is equal to or higher than a predetermined voltage value, the charging device is characterized in that the input sides of the plurality of circuit blocks are connected in series.   The charging device according to claim 1, wherein the connection switching unit includes a semiconductor switching element. A diode that constitutes the rectifying unit and a switching element that is connected in parallel to the diode that constitutes the connection switching unit, or a switching element having an equivalent parallel diode instead of the diode is used,
The charging device according to claim 1, wherein the switching element is made conductive at a timing when a current flows in a forward direction of the diode or the equivalent diode. The predetermined voltage value for switching the input side of the plurality of circuit blocks to either serial or parallel connection is:
A first voltage value for switching the input side from parallel to serial;
2. The charging device according to claim 1, comprising a second voltage value lower than the first voltage value for switching the input side from series to parallel.   2. The circuit block according to claim 1, wherein the circuit block includes a power factor correction circuit and a forward DC / DC converter unit, or a flyback DC / DC converter unit having a power factor correction function. Charging device.   2. The circuit block according to claim 1, wherein each of the circuit blocks includes a circuit block unit that has a plurality of power factor correction functions and converts the voltage of the AC power source into an arbitrary voltage or current and outputs the voltage or current. Charging device. When the input sides of the circuit blocks are connected in parallel, the switching elements of the respective circuit blocks operate with phases shifted from each other,
The charging device according to claim 1, wherein when the input sides of the circuit blocks are connected in series, the switching elements of the circuit blocks operate in the same phase.

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