JP2015186364A - Vehicular power apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strike a balance between suppression of a loss in a vehicular power apparatus and suppression of a shortage in temperature rise of a battery.SOLUTION: If temperature rise-enabled time t1 in which a battery temperature can be raised is equal to or more than temperature rise-requiring time t2 that is required for a temperature-raising device to complete raising a temperature of the battery using power from a sub-DC-DC converter, the sub-DC-DC converter is connected to a temperature adjustment device so as to supply power from the sub-DC-DC converter to the temperature-raising device, raising the temperature of the battery (S150, S160). In contrast, if the temperature rise-enabled time t1 is less than the temperature rise-requiring time t2, a main DC-DC converter is connected to the temperature adjustment device so as to supply power from the main DC-DC converter to the temperature-raising device (S150, S120).

Description

  The present invention relates to an electric power device for a vehicle, and more specifically, is mounted on a vehicle and is connected to a battery, a drive circuit connected to the battery and driving a motor, and connected in parallel to the drive circuit as viewed from the battery and from an external power source. A charger that charges the battery using the power of the main battery, a main DC / DC converter that is attached to the power line that connects the battery and the drive circuit, and a sub-DC that is attached to the power line that connects the battery and the charger The present invention relates to a vehicular power device including a DC / DC converter.

  Conventionally, as this type of vehicle power device, a high-voltage battery, an inverter that drives a motor generator for traveling using power from the high-voltage battery, and power from an external commercial power source or an in-vehicle solar power generation panel are used. Power conversion circuit that supplies a voltage to the battery, an air conditioning unit that controls the temperature in the vehicle using the power from the high voltage battery, and a DC / DC converter that steps down the voltage of the high voltage battery and applies it to the low voltage battery Have been proposed (see, for example, Patent Document 1).

JP 2011-250672 A

  In such a power device, in recent years, in addition to connecting the above-described DC / DC converter (main DC / DC converter) to a power line connecting a high-voltage battery and an inverter, a high-voltage battery and a power conversion circuit (charger) are connected. Is also considered to connect a sub DC / DC converter having a smaller rated value than the main DC / DC converter. When a commercial power supply and a power conversion circuit are connected in a device including two DC / DC converters, power supply to a temperature control device that adjusts the temperature of the high-voltage battery is always performed from the main DC / DC converter. If it is performed, the loss of the power device becomes relatively large due to the relatively large rated value and the voltage also acting on the inverter when the main DC / DC converter is operated. On the other hand, if it is always performed from the sub DC / DC converter, the battery may not be sufficiently heated due to its small rated value.

  The main purpose of the vehicle power device of the present invention is to achieve both suppression of loss of the power device and suppression of insufficient temperature rise of the battery.

  The vehicle power device of the present invention employs the following means in order to achieve the main object described above.

The vehicle power device of the present invention is
A battery mounted on a vehicle, a drive circuit connected to the battery and driving the motor, and connected to the drive circuit in parallel when viewed from the battery and charging the battery using electric power from an external power source A main DC / DC converter attached to a power line connecting the battery and the drive circuit, and a main DC / DC converter attached to a power line connecting the battery and the charger. A vehicle power device comprising a sub DC / DC converter having a smaller rated value,
A temperature adjusting device that operates by receiving power supply and adjusts the temperature of the battery;
Switching means for switching between a first connection state for connecting the main DC / DC converter and the temperature control device and a second connection state for connecting the sub DC / DC converter and the temperature control device;
When the external power source and the charger are connected, the temperature control device uses the power from the sub DC / DC converter within the possible temperature increase time during which the battery can be heated. Control means for setting the switching means to the second connection state when the sub-temperature rise is possible and capable of completing the temperature, and setting the switching means to the first connection state when the sub-temperature rise is not possible;
It is characterized by providing.

  In the vehicle power device according to the present invention, when the external power source and the charger are connected (when the battery can be charged using the power from the external power source), the temperature can be raised so that the battery can be heated. When the temperature can be raised by the temperature control device using the power from the sub DC / DC converter whose rated value is smaller than that of the main DC / DC converter, the switching means is connected to the sub DC / DC converter and the temperature. When the sub-temperature rise is not possible, the switching means is set in the first connection state in which the main DC / DC converter and the temperature control device are connected. Therefore, when the sub-temperature can be raised, the switching means is set in the second connection state to supply power from the sub DC / DC converter to the temperature control device to raise the temperature of the battery. The loss of the power device can be reduced as compared with the case where power is supplied. When the sub-temperature rise is not possible, the switching means is set to the first connection state to supply power from the main DC / DC converter to the temperature adjustment device to raise the temperature of the battery. The battery can be heated more quickly than when power is supplied to the battery (in some cases, the temperature of the battery can be completed within the time during which the temperature can be increased). As a result, it is possible to achieve both suppression of loss of the power device and suppression of insufficient temperature rise of the battery.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 carrying the vehicle electric power apparatus as one Example of this invention. It is a flowchart which shows an example of the process routine at the time of the predetermined temperature increase request | requirement performed by the electronic control unit 70 of an Example.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of an electric vehicle 20 equipped with a vehicle power device as one embodiment of the present invention. As shown in the figure, an electric vehicle 20 according to the embodiment includes a traveling motor 32 configured as, for example, a synchronous generator motor, a power control unit (PCU) 34 serving as a drive circuit for driving the motor 32, and a lithium ion battery, for example. A battery 36 that is configured as a secondary battery and exchanges power with the motor 32 via the power control unit 34, a main relay 44 attached to a power line 42 that connects the power control unit 34 and the battery 36, and a power line 42 A main DC / DC converter 48 that is attached to the power control unit 34 side of the main relay 44 and steps down the power of the power line 42 and supplies it to a power line (only the positive bus is shown) 46, and an external power source such as a household power source Is plugged into the outlet A charger 50 for charging the battery 36 using power from an external power source, a sub-relay 54 attached to the power line 52 connecting the charger 50 and the battery 36, and a sub-relay 54 in the power line 52 A sub DC / DC converter 58 that is attached to the charger side and steps down the power of the power line 52 and supplies it to a power line (only the positive bus is shown) 56, and operates to receive the power supply to raise the temperature of the battery 36 And a changeover switch 62 that connects the temperature raising device 60 to the power line 46 or the power line 56, and an electronic control unit 70 that controls the entire device. The power line 42 and the power line 52 are always connected to a low-voltage battery, an electronic control unit 70, and the like, and auxiliary equipment that is used when the system is on (ignition on, accessory on, etc.) but not when the system is off is the first. 1 is connected via a relay, and is not used when the system is on, but auxiliary equipment used when charging the battery 36 using the power from the external power source when the system is off is connected via the second relay. . In the embodiment, the portion excluding the motor 32 in FIG. 1 corresponds to the “vehicle power device”.

  The power control unit 34 includes an inverter that converts DC power from the battery 36 into AC power and supplies the AC power to the motor 32, and a boost converter that boosts power from the battery 36 and supplies the boosted power to the inverter. Note that only the inverter may be provided without the boost converter.

  The sub DC / DC converter 58 is designed so that the rated value (the power supplied to the power lines 46 and 56 and the loss at that time) is smaller than that of the main DC / DC converter 48.

  Although not shown, the electronic control unit 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, and an input / output port in addition to the CPU. The electronic control unit 70 includes a current sensor that detects a rotational position θm of the rotor of the motor 32 from a rotational position detection sensor that detects a rotational position of the rotor of the motor 32 and a phase current that flows in each phase of the three-phase coil of the motor 32. Phase currents Iu, Iv, Iw from the voltage sensor, voltage sensor for detecting the voltage, current and temperature of the battery 36, current sensor, voltage Vb between terminals from the temperature sensor, charge / discharge current Ib, battery temperature Tb, ignition switch (start switch) ), The shift position SP from the shift position sensor that detects the operation position of the shift lever, the accelerator opening Acc from the accelerator pedal position sensor that detects the depression amount of the accelerator pedal, and the depression amount of the brake pedal Brake pedal from brake pedal position sensor Position BP, and a vehicle speed V from a vehicle speed sensor is input via the input port. From the electronic control unit 70, a switching control signal to the switching element of the drive circuit (inverter or boost converter), a control signal to the main relay 44, a control signal to the main DC / DC converter 48, a control signal to the charger 50 , A control signal to the temperature raising device 60, a control signal to the sub relay 54, a control signal to the sub DC / DC converter 58, a control signal to the temperature raising device 60, and the like are output via the output port. The electronic control unit 70 calculates the rotational speed Nm of the motor 32 based on the rotational position θm of the rotor of the motor 32 from the rotational position detection sensor, or based on the charge / discharge current Ib of the battery 36 from the current sensor. The storage ratio SOC, which is the ratio of the amount of power that can be discharged from the battery 36 at that time, to the total capacity is calculated, or the battery 36 is charged / discharged based on the calculated storage ratio SOC and the battery temperature Tb from the temperature sensor. The input / output limits Win and Wout, which are the maximum allowable power, are calculated.

  In the electric vehicle 20 of the embodiment configured as described above, when the ignition switch is turned off at a home or a preset charging point and a plug-in operation is performed in which the plug is inserted into the outlet of the external power source, The battery 36 is charged with power within the input limit Win range of the battery 36 until the storage ratio SOC of the battery 36 reaches a predetermined ratio Send (for example, full charge or a slightly lower storage ratio) using the power. The charger 50 is controlled as described above. Here, when the timer charging function (a function for setting the scheduled charging completion time of the battery 36, etc.) is on, the current storage ratio SOC of the battery 36 and a predetermined ratio so that the charging of the battery 36 is completed at the scheduled charging completion time. The charging start scheduled time is set according to the difference from Send, and charging of the battery 36 is started when the charging starting scheduled time is reached. When the timer charging function is off, charging of the battery 36 is started immediately. It was supposed to be.

  Next, the operation of the electric vehicle 20 of the embodiment thus configured, particularly during external charging in which the battery 36 is charged using the power from the external power source when the system is off (the charging of the battery 36 after the plug-in operation is performed). The operation when the temperature rise of the battery 36 is requested is also described. FIG. 2 is a flowchart illustrating an example of a predetermined temperature increase request processing routine executed by the electronic control unit 70 of the embodiment. This routine is repeatedly executed when the temperature of the battery 36 is requested during external charging. When the first execution of this routine is started (immediately after the plug-in operation is performed), the main relay 44 is turned off and the sub-relay 54 is turned on.

  When the predetermined temperature increase request processing routine is executed, the electronic control unit 70 first determines that the infrastructure-side chargeable power P1 as power that can be supplied from the external power source to the battery 36 during external charging, or the battery 36 during external charging. Data such as battery-side chargeable power P2 as acceptable power is input (step S100). Here, the infrastructure-side chargeable power P1 is obtained by inputting a value according to the specifications of the external power source (for example, 100V, 30A AC power source, etc.) from the external power source through communication or the like. Further, the battery-side chargeable power P2 is input as an absolute value of the input limit Win of the battery 36.

  When the data is input in this way, the infrastructure-side chargeable power P1 and the battery-side chargeable power P2 are compared (step S110). This comparison process is a process for determining whether or not all the electric power from the external power source can be supplied to the battery 36.

  When the infrastructure-side chargeable power P1 is less than or equal to the battery-side chargeable power P2, it is determined that all of the power from the external power supply can be supplied to the battery 36, and the main relay 44 is turned on ( Hold), the temperature raising device 60 and the power line 46 are connected by the changeover switch 62 (it is held in this state), and the main DC / DC converter 48 and the power line 46 are connected from the power line 42 (battery 36). The main DC / DC converter 48 is controlled so that the electric power is supplied to the temperature raising device 60 through (step S120), and this routine is finished. In this case, by supplying electric power from the main DC / DC converter 48 to the temperature raising device 60, a large amount of electric power can be supplied to the temperature raising device 60 to quickly raise the temperature of the battery 36, but the power is large. In addition, the loss of the power device at that time is relatively large due to the fact that the voltage also acts on the drive circuit 34.

  When the infrastructure-side chargeable power P1 is larger than the battery-side chargeable power P2, it is determined that not all of the power from the external power source can be supplied to the battery 36, and the temperature rise as a time during which the battery 36 can be raised A possible time t1 is set (step S130), and a temperature increase required time t2 is set as a time required until the temperature increase of the battery 36 is completed by the temperature increase device 60 using the electric power from the sub DC / DC converter 58. (Step S140). Here, the temperature rise possible time t1 is obtained based on the current storage ratio SOC of the battery 36, the predetermined ratio Send, and the charging power Wb (= Vb · Ib) of the battery 36 when the timer charging function is off. The remaining charging time until 36 charging is completed is set, and when the timer charging function is on, the time from the current time to the scheduled charging completion time is set. Further, the required temperature increase time t2 includes the current battery temperature Tb, the predetermined temperature increase target temperature Tbset, and the battery 36 per unit time when power is supplied from the sub DC / DC converter 58 to the temperature increasing device 60. The time required to complete the temperature increase of the battery 36 obtained based on the predicted increase temperature ΔTb is set.

  Then, the temperature rise possible time t1 and the temperature rise required time t2 are compared (step S150). This comparison process is performed while the battery 36 can be heated when power is supplied from the sub DC / DC converter 58 to the temperature raising device 60 (in the embodiment, until the battery 36 is completely charged). Is a process for determining whether or not the temperature increase can be completed.

  When the temperature rise possible time t1 is equal to or greater than the temperature rise required time t2, power can be supplied from the sub DC / DC converter 58 to the temperature raising device 60 and the temperature rise of the battery 36 can be completed while the temperature of the battery 36 can be raised. The main relay 44 is turned off (the state is maintained when it is off), the temperature raising device 60 and the power line 56 are connected by the changeover switch 62 (the state is maintained in this state), and the power line The sub DC / DC converter 58 is controlled so that power is supplied to the temperature raising device 60 from the 52 (charger 50) via the sub DC / DC converter 58 and the power line 56 (step S160), and this routine is finished. To do. In this case, by supplying power from the sub DC / DC converter 58 to the temperature raising device 60, the rated value is smaller than that of the main DC / DC converter 48 (output power is small), and the voltage is applied to the drive circuit 34. The battery 36 can be heated while suppressing the loss of the power device because it does not act.

  On the other hand, when the temperature rise possible time t1 is less than the temperature rise required time t2, when the electric power is supplied from the sub DC / DC converter 58 to the temperature raising device 60, the temperature rise of the battery 36 is completed while the temperature of the battery 36 can be raised. The main relay 44 is turned on (the state is maintained when it is turned on), and the temperature raising device 60 and the power line 46 are connected by the changeover switch 62 (the state is maintained in this state). The main DC / DC converter 48 is controlled so that power is supplied from the line 42 (battery 36) to the temperature raising device 60 via the main DC / DC converter 48 and the power line 46 (step S120), and this routine is finished. To do. In this case, by supplying electric power from the main DC / DC converter 48 to the temperature raising device 60, a large amount of electric power can be supplied to the temperature raising device 60 and the temperature of the battery 36 can be raised more quickly (time when temperature can be raised). In some cases, it is possible to complete the temperature increase of the battery 36 in the inside).

  According to the electric vehicle 20 equipped with the vehicle power device of the embodiment described above, the sub DC / DC converter 58 and the temperature control device 60 are connected when the temperature rise possible time t1 is equal to or longer than the temperature rise required time t2. Thus, by supplying electric power from the sub DC / DC converter 58 to the temperature raising device 60 and raising the temperature of the battery 36, power is supplied compared to the case where electric power is supplied from the main DC / DC converter 48 to the temperature raising device 60. The temperature of the battery 36 can be raised while suppressing the loss of the device. On the other hand, when the temperature rise possible time t1 is less than the temperature rise required time t2, the main DC / DC converter 48 and the temperature adjustment device 60 are connected to supply power from the main DC / DC converter 48 to the temperature raising device 60. Thus, the temperature of the battery 36 can be raised quickly as compared with the case where electric power is supplied from the sub DC / DC converter 58 to the temperature raising device 60. As a result, it is possible to achieve both suppression of power device loss and suppression of insufficient temperature rise of the battery 36.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the battery 36 corresponds to “battery”, the power control unit 34 corresponds to “drive circuit”, the charger 50 corresponds to “charger”, and the main DC / DC converter 48 corresponds to “main DC / DC”. It corresponds to a “DC converter”, the sub DC / DC converter 58 corresponds to a “sub DC / DC converter”, the temperature raising device 60 corresponds to a “temperature adjusting device”, and the changeover switch 62 corresponds to a “switching means”. The electronic control unit 70 corresponds to “control means”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of electric power devices for vehicles.

  20 electric vehicle, 32 motor, 34 power control unit, 36 battery, 42, 46, 52, 56 power line, 44 main relay, 48 main DC / DC converter, 50 charger, 54 sub relay, 58 sub DC / DC converter, 60 temperature raising device, 62 changeover switch, 70 electronic control unit.

Claims (1)

A battery mounted on a vehicle, a drive circuit connected to the battery and driving the motor, and connected to the drive circuit in parallel when viewed from the battery and charging the battery using electric power from an external power source A main DC / DC converter attached to a power line connecting the battery and the drive circuit, and a main DC / DC converter attached to a power line connecting the battery and the charger. A vehicle power device comprising a sub DC / DC converter having a smaller rated value,
A temperature adjusting device that operates by receiving power supply and adjusts the temperature of the battery;
Switching means for switching between a first connection state for connecting the main DC / DC converter and the temperature control device and a second connection state for connecting the sub DC / DC converter and the temperature control device;
When the external power source and the charger are connected, the temperature control device uses the power from the sub DC / DC converter within the possible temperature increase time during which the battery can be heated. Control means for setting the switching means to the second connection state when the sub-temperature rise is possible and capable of completing the temperature, and setting the switching means to the first connection state when the sub-temperature rise is not possible;
A vehicle power device comprising:

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