Control device for vehicle batteries

Abstract

To provide a control device for a vehicular storage battery that can simplify control for warmup of a storage battery and be applicable to a vehicle not including a step-up converter.SOLUTION: At least one of inverters 52 is heated by an inverter heat generation control unit 104 causing a constant current Iinv1 to pass through the inverter 52 for a predetermined time, and heating of the at least one inverter 52 causes a high-voltage battery (storage battery) 54 to warm up via a cooling circuit 84. Accordingly, control for warmup of the high-voltage battery (storage battery) 54 is simply performed by causing the constant current Iinv1 to pass through the inverter 52 for the predetermined time. Further, this inverter heat generation control can also be applied to a vehicle 10 not including a step-up converter.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle battery warming device for warming a battery in a vehicle that supplies drive current from a battery to an electric motor via an inverter. control

Background Art

[0002] In a vehicle including an inverter that controls drive current supplied from a battery to an electric motor and a boost converter that boosts the voltage of the battery by switching control of a switching element and outputs the boosted voltage to the inverter, a ripple current is increased by reducing the switching frequency of the boost converter, and thereby a ripple heating control for increasing heat generation of the internal resistance of the battery is performed, and a drive device for a vehicle that warms the battery by self-heating of the battery itself has been proposed. For example, the drive device for a vehicle shown in Patent Document 1 is such a device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the power range in which a battery can be charged and discharged becomes narrow at low temperatures. Therefore, it is preferable to warm the battery in order to increase the power range in which it can be charged and discharged. However, since the battery that can be charged and discharged within a narrow power range at low temperatures is self-heating, the switching frequency of the boost converter for increasing the ripple current required for heat generation by the internal resistance of the battery based on the detected temperature of the temperature sensor that detects the temperature of the battery is calculated, and there is a drawback that the control becomes complicated. In addition, it cannot be applied to vehicles not equipped with a boost converter, and there is also a drawback that applicable vehicles are limited. ​

[0005] This invention was made against the above circumstances, and its objective is to provide a control device for a vehicle battery that allows for easy control of battery warm-up and can be applied to vehicles that do not have a boost converter. [Means for solving the problem]

[0006] The gist of this invention is a vehicle comprising an inverter that controls the drive current supplied from a storage battery to an electric motor, and a cooling circuit that circulates a refrigerant to cool the storage battery and the inverter. Battery A control device wherein a constant DC inverter current is passed through the inverter for a predetermined time, thereby generating heat in the inverter and warming up the storage battery via the cooling circuit. Execute inverter heat generation control The inverter heat generation control unit includes Furthermore, the inverter heat generation control unit terminates the inverter heat generation control by stopping the passage of the inverter current through the inverter after a predetermined time has elapsed since the inverter heat generation control was started. It is the matter. [Effects of the Invention]

[0007] According to the present invention, the inverter heat generation control unit generates a certain DC inverter Current For a predetermined time, the inverter As the inverter is passed through, it generates heat, and this heat from the inverter warms up the battery via the cooling circuit. This results in a certain temperature. DC inverter Current scheduled time By passing the signal through an inverter, control for warming up the battery can be easily implemented. Furthermore, this inverter-based heat generation control can be applied even to vehicles that do not have a boost converter. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram illustrates the schematic configuration of a vehicle to which the present invention is applied, as well as the main parts of the control functions and control systems for various control functions in the vehicle. [Figure 2] This diagram provides a detailed explanation of the battery and power control circuit used to drive and control the electric motor installed in the vehicle shown in Figure 1. [Figure 3]Figure 1 is a schematic diagram showing a refrigerant circulation circuit that circulates refrigerant to cool the battery and inverter in the vehicle. [Figure 4] Figure 2 is a schematic diagram illustrating the configuration of the inverter. [Figure 5] This is a time chart illustrating the operation of the heat generation control unit shown in Figure 1. [Figure 6] This is a time chart illustrating the operation of the heat generation control unit in the comparative example. [Figure 7] Figure 1 is a flowchart illustrating the control operation by the heat generation control unit. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Examples]

[0010] In Figure 1, the vehicle 10 includes an engine 12, a first electric motor MG1, and a second electric motor MG2. The vehicle 10 also includes drive wheels 14 and a power transmission device 16 provided in the power transmission path between the engine 12 and the drive wheels 14. The vehicle 10 in this embodiment is an electric vehicle, particularly a hybrid vehicle, equipped with an engine 12 and a second electric motor MG2 that function as a power source.

[0011] Engine 12 is a known internal combustion engine. The engine torque Te of engine 12 is controlled by an engine control device 50 installed in the vehicle 10, which is controlled by an electronic control device 90, which will be described later.

[0012] The first electric motor MG1 and the second electric motor MG2 are each rotating electric machines, so-called motor generators. The first electric motor MG1 and the second electric motor MG2 are each connected to a high-voltage battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The torque of the first electric motor MG1, MG1 torque Tg, and the torque of the second electric motor MG2, MG2 torque Tm, are controlled by the inverter 52 controlled by an electronic control device 90, which will be described later. The first electric motor MG1 and the second electric motor MG2 are housed in a case 18 that is attached to the vehicle body.

[0013] The power transmission device 16 includes a damper 20, an input shaft 22, a transmission unit 24, a compound gear 26, a driven gear 28, a driven shaft 30, a final gear 32, a differential gear 34, a reduction gear 36, etc., within a case 18. The power transmission device 16 also includes a rotor shaft RSmg1 integrally connected to the rotor MG1r of the first electric motor MG1, and a rotor shaft RSmg2 integrally connected to the rotor MG2r of the second electric motor MG2, within a case 18. Furthermore, the power transmission device 16 includes a pair of drive shafts 38 connected to the differential gear 34, etc.

[0014] The input shaft 22 functions as an input rotating member of the transmission unit 24 and is connected to the crankshaft 12a of the engine 12 via a damper 20 or the like. Power from the engine 12 is input to the input shaft 22. The transmission unit 24 is connected to the input shaft 22. The compound gear 26 is a rotating body on the output side of the transmission unit 24. A drive gear 26a is formed on a part of the outer peripheral surface of the compound gear 26. The drive gear 26a is an output rotating member of the transmission unit 24. The driven gear 28 meshes with the drive gear 26a. The driven shaft 30 fixedly mounts the driven gear 28 and the final gear 32 in a non-rotatable relative manner. The final gear 32 has a smaller diameter than the driven gear 28 and meshes with the differential ring gear 34a of the differential gear 34. The reduction gear 36 has a smaller diameter than the driven gear 28 and meshes with the driven gear 28. A rotor shaft RSm g2 is connected to the reduction gear 36, and the second electric motor MG2 is connected in a power-transmittable manner.

[0015] The power transmission device 16 transmits the power output from the engine 12 to the driven gear 28 via the transmission unit 24. Also, the power transmission device 16 transmits the power output from the second electric motor MG2 to the driven gear 28 via the reduction gear 36. The power transmission device 16 transmits the power transmitted to the driven gear 28 to the drive wheels 14 sequentially via the driven shaft 30, the final gear 32, the differential gear 34, the drive shaft 38, etc.

[0016] The speed change section 24 includes a first electric motor MG1, a rotor shaft RSm1, and a planetary gear device 40. The planetary gear device 40 is a planetary gear device including a sun gear S, a carrier CA, a ring gear R, and a pinion P. The rotor shaft RSm1 of the first electric motor G1 is connected to the sun gear S in a power transmissible manner. The carrier CA is connected to the engine 12 in a power transmissible manner via an input shaft 22 or the like. The ring gear R is formed on a part of the inner peripheral surface of the compound gear 26 and is integrally connected to the drive gear 26a. The pinion P is supported by the carrier CA so as to be rotatable and revolvable. The ring gear R meshes with the sun gear S via the pinion P.

[0017] Power of the engine 12 is input to the planetary gear device 40 via the input shaft 22. The first electric motor MG1 is an electric motor connected to the planetary gear device 40 in a power transmissible manner. The planetary gear device 40 is a power split mechanism that mechanically splits the power of the engine 12 input to the carrier CA between the first electric motor MG1 and the drive gear 26a. The speed change section 24 is an electric speed change mechanism controlled by the first electric motor MG1.

[0018] The vehicle 10 further includes a mechanical oil pump (hereinafter referred to as MOP) 56. The MOP 56 is connected to the input shaft 22 in a power transmissible manner. The MOP 56 is rotationally driven by the engine 12 to supply oil Fld used for lubricating and cooling each part of the power transmission device 16.

[0019] FIG. 2 is a diagram for explaining an example of the electrical configuration of a power control circuit 64 including an inverter 52 and the like provided in the vehicle 10.

[0020] The high-voltage battery 54 that functions as a storage battery is a chargeable and dischargeable DC power source, and is a secondary battery such as a nickel-hydrogen secondary battery or a lithium-ion battery.

[0021] The high-voltage battery 54 supplies stored power to the first motor MG1 and the second motor MG2 via the power control circuit 64. Additionally, the high-voltage battery 54 receives power from the power generation control of the first motor MG1 and power from the regenerative control of the second motor MG2 via the power control circuit 64. The high-voltage battery 54 is a battery for vehicle propulsion.

[0022] The DC-DC converter 62 is connected to the high-voltage battery 54. The DC-DC converter 62 functions as a charging device that steps down the voltage of the high-voltage battery 54 to a voltage equivalent to that of the auxiliary battery 58 and charges the auxiliary battery 58. The auxiliary battery 58 supplies power to operate the auxiliary equipment installed in the vehicle 10. The auxiliary battery 58 also supplies power to operate the electronic control unit 90, which will be described later.

[0023] The power control circuit 64 includes an inverter 52 that controls the power exchanged between the high-voltage battery 54 and the first motor MG1 and the second motor MG2, respectively. In this embodiment, the power control circuit 64 further boosts the voltage of the high-voltage battery 54 and supplies it to the inverter 52, while not including a boost converter that steps down the voltage converted to DC by the inverter 52 and supplies it to the high-voltage battery 54.

[0024] The inverter 52 includes an MG1 power module 68, an MG2 power module 70, and a capacitor 72, etc. The MG1 power module 68 includes six transistors 74u, 74v, 74w, 76u, 76v, and 76w, and six diodes 75u, 75v, 75w, 77u, 77v, and 77w connected in parallel in the opposite direction to the transistors 74u, 74v, 74w, 76u, 76v, and 76w, respectively. In this embodiment, unless otherwise specified, transistors 74u, 74v, and 74w are referred to as transistor 74, and transistors 76u, 76v, and 76w are referred to as transistor 76. The MG1 power module 68, with transistors 74, 76, etc., constitutes a three-phase bridge circuit of U-phase, V-phase, and W-phase. Transistors 74 and 76 are driven on and off as switching elements to convert DC current into three-phase AC current. Transistor 74 constitutes the upper arm of transistors 74 and 76. Transistor 76 constitutes the lower arm of transistors 74 and 76. The MG2 power module 70 has the same configuration as the MG1 power module 68, so the description of the MG2 power module 70 is omitted. The first motor MG1 and the second motor MG2 are three-phase AC synchronous motors, each driven by an inverter 52 having multiple switching elements.

[0025] The inverter 52 converts the DC current from the high-voltage battery 54 into AC current to drive the first motor MG1 and the second motor MG2. The inverter 52 converts the AC current generated by the first motor MG1 using the power of the engine 12, and the AC current generated by the second motor MG2 using regenerative braking, into DC current and supplies it to the high-voltage battery 54. The inverter 52 supplies the AC current generated by the first motor MG1 as power to drive the second motor MG2 according to the driving conditions.

[0026] Figure 3 shows the cross-sectional structure of transistors 74 and 76, which are made of semiconductor chips such as Si and GaN and function as the switching elements described above. In Figure 3, transistors 74 and 76 are sandwiched between an emitter-side path 80 and a collector-side path 82. The emitter-side path 80 is stacked in order above transistors 74 and 76 and includes an element upper solder 80a, a copper block 80b, a CB upper solder 80c, a heat spreader 80d, a first upper grease layer 80e, a ceramic plate 80f, a second upper grease layer 80g, and an upper cooler fin 80h. The collector-side path 82 is stacked in order below transistors 74 and 76 and includes an element lower solder 82a, a heat spreader 82b, a first lower grease layer 82c, a ceramic plate 82d, a second lower grease layer 82e, and a lower cooler fin 82f. The first upper grease layer 80e, the second upper grease layer 80g, the first lower grease layer 82c, and the second lower grease layer 82e, which are sandwiched inside transistors 74 and 76, expand due to the self-heating of transistors 74 and 76 and are pushed out to the outside of transistors 74 and 76. When the self-heating of transistors 74 and 76 subsides, the grease does not fully return to the inside of transistors 74 and 76. This type of inverter degradation, known as grease leakage degradation, is influenced (contributed to) by the number of cycles of heat generation and heat dissipation of the switching elements. Therefore, it is desirable to reduce the number of cycles of heat generation and heat dissipation of the switching elements.

[0027] As shown in Figure 4, the vehicle 10 is equipped with a closed-circuit cooling circuit 84 that uses water as a coolant and circulates the coolant using a water pump (not shown) to cool the high-voltage battery 54 and the inverter 52, which are storage batteries. The cooling circuit 84 has an oil cooler 88 that performs heat exchange between the oil (coolant) circulated in the motor cooling circuit 86 by an oil pump (not shown) to cool the first motor MG1 and the second motor MG2 and the water in the cooling circuit 84. The cooling circuit 84 may have a heat sink (radiator) as needed.

[0028] Returning to Figure 1, the vehicle 10 is equipped with an electronic control unit 90, which acts as a controller for the vehicle 10, including control devices related to the control of the engine 12 and electric motors. The electronic control unit 90 is composed of a so-called microcomputer, for example, which includes a CPU, RAM, ROM, input / output interface, etc. The electronic control unit 90 performs various controls on the vehicle 10 by having the CPU perform signal processing according to a program pre-stored in ROM, while utilizing the temporary storage function of RAM.

[0029] The electronic control unit 90 is supplied with various signals based on values ​​detected by various sensors installed in the vehicle 10 (for example, engine rotation speed sensor 91, output rotation speed sensor 92, MG1 rotation speed sensor 93, MG2 rotation speed sensor 94, accelerator opening sensor 95, throttle valve opening sensor 96, brake switch 97, shift lever operating position detection switch 98, temperature sensor 99, etc.). These signals include various types of signals (for example, engine rotation speed Ne (= input rotation speed Ni), output rotation speed No corresponding to vehicle speed V, MG1 rotation speed Ng which is the rotation speed of the first electric motor MG1, MG2 rotation speed Nm which is the rotation speed of the second electric motor MG2, accelerator opening θacc, throttle valve opening θth, brake on Bon, shift lever operating position Psft, and high-voltage battery 54 temperature Tb).

[0030] The electronic control unit 90 outputs various command signals (for example, an engine control command signal Se for controlling the engine 12, and MG control command signals Smg for controlling the first motor MG1 and the second motor MG2, respectively) to each device installed in the vehicle 10 (for example, an engine control control unit 50, an inverter 52, etc.).

[0031] The electronic control unit 90 is functionally equipped with a power source control unit 102 and a heat generation control unit 104 in order to realize various controls in the vehicle 10.

[0032] The power source control unit 102 includes an engine control function that controls the operation of the engine 12, and an electric motor control function that controls the operation of the first electric motor MG1 and the second electric motor MG2 via the inverter 52.

[0033] The power source control unit 102 calculates the amount of drive requested by the driver to the vehicle 10 by applying, for example, the accelerator opening θacc and the vehicle speed V to the drive request amount map. The drive request amount map is a predetermined relationship for determining the drive request amount, which has been experimentally or design-wise determined and stored in advance. The drive request amount is, for example, the drive torque Tr required for the vehicle 10, i.e., the required drive torque Trdem [Nm] at the drive wheels 14. The required drive torque Trdem is, conversely, the required drive power Prdem [W] at the vehicle speed V at that time. The drive request amount can also be the required drive force Frdem [N] at the drive wheels 14, etc.

[0034] The power source control unit 102 outputs an engine control command signal Se and an MG control command signal Smg to achieve the requested drive power Prdem, taking into consideration, for example, transmission losses and auxiliary loads. For example, the engine control command signal Se is the command value of engine power Pe, which is the power of engine 12 that outputs engine torque Te at the engine rotation speed Ne at that time, taking into consideration the engine's optimal fuel consumption point. The MG control command signal Smg is the command value of the generated power Wg of the first electric motor MG1 that outputs MG1 torque Tg at the MG1 rotation speed Ng when the command is output as a reaction torque to engine torque Te. The MG control command signal Smg is the command value of the power consumption Wm of the second electric motor MG2 that outputs MG2 torque Tm at the MG2 rotation speed Nm when the command is output for the generated power Wg. The engine's optimal fuel consumption point is predetermined as the engine operating point that yields the best total fuel consumption in the vehicle 10, taking into consideration, for example, the fuel consumption of the engine 12 alone, the charge and discharge efficiency of the high-voltage battery 54, and the transmission efficiency of the power transmission device 16.

[0035] The power source control unit 102 sets the vehicle 10 to BEV driving mode when the requested drive power Prdem is in the BEV driving range, which is smaller than a predetermined threshold. On the other hand, the power source control unit 102 sets the vehicle 10 to HEV driving mode when the requested drive power Prdem is in the HEV driving range, which is greater than or equal to a predetermined threshold. On the other hand, even when the requested drive power Prdem is in the BEV driving range, the power source control unit 102 activates HEV driving mode when charging of the high-voltage battery 54 is required or when warming up the engine 12 is required.

[0036] The heat generation control unit 104, when the P range (parking range) is selected as the shift range of the vehicle 10, and the temperature Tb of the high-voltage battery 54 is lower than the preset warm-up requirement determination temperature Td of the high-voltage battery 54, causes at least one of the inverters 52 to generate heat by passing a constant inverter current (DC) Iinv1 for warm-up through at least one of the inverters 52 for a predetermined time, and then transfers the heat generated in that inverter 52 to the high-voltage battery (storage battery) 54 via the cooling circuit 84 to warm up the high-voltage battery 54. The warm-up requirement determination temperature Td is set to a temperature at which the power range that the high-voltage battery (storage battery) 54 can charge and discharge narrows and interferes with the control of the vehicle 10, for example, 0°C. The constant inverter current (DC) Iinv1 is passed through, for example, at least one of the transistors 74u, 74v, and 74w, at least one coil of the first motor MG1, and at least one of the transistors 76u, 76v, and 76w.

[0037] Figure 5 shows the current used by the heat generation control unit 104 to operate one inverter 52. In Figure 5, the constant inverter current Iinv, shown by the solid line, is, for example, 200A, and the predetermined time t1-t2 is, for example, 30 seconds. In Figure 5, the dashed line shows the temperature Tinv of the inverter 52, and the dashed line shows the inverter current Iinv2 in the comparative example shown in Figure 6. The constant inverter current Iinv1 substantially encompasses the inverter current Iinv2 in the comparative example, which changes in a pulse-like manner every 6 seconds, and exceeds the integral value (area value) of the inverter current Iinv2 in the comparative example.

[0038] Figure 6 is a two-dimensional coordinate system similar to Figure 5, illustrating the operation of the heat generation control in a comparative example of the inverter heat generation control unit 104. In this case, the inverter heat generation control unit 104 sequentially calculates the amount of heat dissipation required to warm up the high-voltage battery (storage battery) 54 based on (responding to) the change in the temperature Tb of the high-voltage battery 54, with a shorter period than in Figure 5, for example, a 6-second period. It then sequentially calculates the inverter current Iinv2 required to generate the calculated heat, and operates at least one of the inverters 52 with that inverter current Iinv2. The solid line in Figure 6 shows the inverter current Iinv2, which changes at predetermined time intervals, for example, every 6 seconds, due to the effects of wind, and the dashed line shows the temperature Tinv of the inverter 52.

[0039] Figure 7 is a flowchart illustrating the main parts of the control operation of the electronic control unit 90. In Figure 7, in step S1 (the step will be omitted hereafter), it is determined whether the P range, which prevents the vehicle 10 from moving by the vehicle 10's parking lock mechanism, is selected as the shift range of the vehicle 10. If the determination in S1 is negative, this routine is terminated. However, if the determination in S1 is positive, in S2, it is determined whether the temperature Tb of the high-voltage battery 54 is lower than the pre-set warm-up requirement determination temperature Td of the high-voltage battery 54, for example, 0°C. If the determination in S2 is negative, this routine is terminated. However, if the determination in S2 is positive, in S3, which corresponds to the inverter heat generation control unit 104, inverter heat generation control is executed for a predetermined time. A constant inverter current Iinv1 for warming up is passed through at least one of the inverters 52 for a predetermined time, causing at least one of the inverters 52 to generate heat. This heat generated in at least one of the inverters 52 is then transferred to the high-voltage battery (storage battery) 54 via the cooling circuit 84 to warm up the high-voltage battery 54.

[0040] As described above, according to the electronic control device 90 of this embodiment, the inverter heat generation control unit 104 causes at least one of the inverters 52 to generate heat by passing a constant current Iinv1 through it for a predetermined time, and this heat generated by at least one of the inverters 52 warms up the high-voltage battery (storage battery) 54 via the cooling circuit 84. This makes it easy to control the warming up of the high-voltage battery (storage battery) 54 by passing a constant current Iinv1 through the inverter 52 for a predetermined time. Furthermore, this inverter heat generation control can also be applied to vehicles 10 that do not have a boost converter. In addition, since the inverter heat generation control unit 104 generates heat in the inverter 52 by passing a constant inverter current (DC) Iinv1 through it for a predetermined time, the heating and dissipation of heat in the inverter 52 is not repeated, and the inverter degradation mode known as grease depletion degradation is suppressed.

[0041] Furthermore, according to the electronic control device 90 of this embodiment, the inverter heat generation control performed by the inverter heat generation control unit 104 is performed when the P range is selected as the shift range of the vehicle 10. In the P range, the vehicle is stopped and its movement is prevented by the parking lock mechanism of the vehicle 10, so there is an advantage that the inverter heat generation control does not affect the behavior of the vehicle 10.

[0042] Furthermore, according to the electronic control device 90 of this embodiment, the inverter heat generation control performed by the inverter heat generation control unit 104 is performed when the temperature Tb of the high-voltage battery (storage battery) 54 is lower than the preset warm-up requirement determination temperature Td of the high-voltage battery (storage battery) 54. As a result, the high-voltage battery (storage battery) 54 is warmed up at low temperatures when the power range in which it can be charged and discharged is relatively narrow, and the power range in which the high-voltage battery (storage battery) 54 can be charged and discharged is quickly expanded.

[0043] Furthermore, according to the electronic control device 90 of this embodiment, in the inverter heat generation control performed by the inverter heat generation control unit 104, the constant current Iinv1 is a value that includes the variable current Iinv2 used to generate the amount of heat dissipation required to warm up the high-voltage battery (storage battery) 54, calculated based on the temperature Tb of the high-voltage battery (storage battery) 54, compared to the comparative example where a variable current Iinv2 is used to generate that amount of heat dissipation. This simplifies the control for warming up the high-voltage battery (storage battery) 54.

[0044] Furthermore, according to the electronic control device 90 of this embodiment, the refrigerant in the cooling circuit 84 is water, and the cooling circuit 84 has an oil cooler 88 that performs heat exchange between the oil in the motor cooling circuit 86 that cools the first motor MG1 and the second motor MG2 and the water in the cooling circuit 84. As a result, when the inverter heat generation control unit 104 causes a constant current Iinv1 to pass through the inverter 52 for a predetermined time, causing the coils of the first motor MG1 and the second motor MG2 to heat up, the heat generated in the first motor MG1 and the second motor MG2 is also transmitted to the high-voltage battery (storage battery) 54 via the oil cooler 88 and the cooling circuit 84, contributing to the warming up of the high-voltage battery (storage battery) 54. This further accelerates the warming up of the high-voltage battery (storage battery) 54.

[0045] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other embodiments.

[0046] For example, the vehicle 10 in the above-described embodiment did not have a boost converter between the high-voltage battery (storage battery) 54 and the inverter 52, but it may have a boost converter between the high-voltage battery (storage battery) 54 and the inverter 52.

[0047] Furthermore, although the vehicle 10 in the above-described embodiment was a hybrid vehicle equipped with an engine 12 and a first electric motor MG1 and a second electric motor MG2 as power sources, it may also be an electric vehicle equipped with an electric motor as a power source.

[0048] Furthermore, in the vehicle 10 of the above-described embodiment, the inverter heat generation control unit 104 caused a constant inverter current (DC) Iinv1 to pass through for a predetermined time, as shown in Figure 5, in order to generate heat in the inverter 52 to warm up the high-voltage battery 54. This constant inverter current (DC) Iinv1 or the command value of the inverter current (DC) Iinv1 does not need to be strictly constant; it is acceptable for the amplitude or period to fluctuate to an extent that does not cause repeated heat generation and heat dissipation in the inverter (switched element) 52, which would cause grease leakage and deterioration in the inverter 52.

[0049] It should be noted that the above-described embodiment is merely one example, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0050] 10: Vehicles 52: Inverter 54: High-voltage battery (storage battery) 56: Mechanical oil pump 74 (74u, 74v, 74w): Transistor (switching element, upper arm) 76 (76u, 76v, 76w): Transistor (switching element, lower arm) 90: Electronic control unit (control device) 104: Inverter Heat Generation Control Unit MG1: 1st electric motor (electric motor) MG2: 2nd electric motor (electric motor)

Claims

1. A control device for a vehicle battery, comprising an inverter that controls the drive current supplied from the battery to an electric motor, and a cooling circuit that circulates a refrigerant to cool the battery and the inverter, The inverter heat generation control unit performs inverter heat generation control, which generates heat in the inverter by passing a constant DC inverter current through the inverter for a predetermined time, and warms up the storage battery via the cooling circuit. The inverter heat generation control unit terminates the inverter heat generation control by stopping the flow of the inverter current through the inverter after a predetermined time has elapsed since the inverter heat generation control was started. A control device for a vehicle battery, characterized by the following features.

2. The inverter heat generation control performed by the inverter heat generation control unit is performed when the P range is selected as the shift range of the vehicle. A control device for a vehicle battery according to feature 1.

3. The inverter heat generation control performed by the inverter heat generation control unit is executed when the temperature is lower than the preset warm-up requirement determination temperature of the storage battery. A control device for a vehicle battery according to feature 1.

4. The constant DC inverter current is a value that includes the current that is varied to generate the amount of heat dissipation necessary for warming up the battery, which is calculated sequentially based on the temperature change of the battery. A control device for a vehicle battery according to feature 1.

5. The refrigerant in the aforementioned cooling circuit is water. The cooling circuit includes an oil cooler that performs heat exchange between the oil in the motor cooling circuit that cools the motor and the water in the cooling circuit. A control device for a vehicle battery according to feature 1.

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