Electric vehicle

Abstract

To provide an electric vehicle which can balance heat-up of a battery with securing required drive force during travelling.SOLUTION: An electric vehicle comprises: a first rotary electric machine which drives one of a front wheel and a rear wheel; a second rotary electric machine which drives the other of the front wheel and the rear wheel; a battery which can supply the first rotary electric machine and the second rotary electric machine with electric power; a cooling liquid circulation circuit which collects heat generated in the first rotary electric machine through the cooling liquid to supply the battery with the heat; and a control unit which controls drive of the first rotary electric machine and the second rotary electric machine. The first rotary electric machine is a winding field motor. The control unit performs, when heat-up of the battery is required during traveling, control to raise temperature of the battery in which current flows only in a stator coil of the first rotary electric machine without flowing current in a rotor coil, collect heat generated by flowing current in the stator coil through the cooling liquid of the cooling liquid circulation circuit to supply the battery with the heat to raise temperature of the battery, and output required drive force for traveling through the second rotary electric machine.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an electric vehicle. [Background technology]

[0002] Patent Document 1 discloses a technique for setting a q-axis current value according to the required driving force required for running an electric vehicle, while setting a d-axis current value that promotes warm-up operation of the battery in cooperation with the q-axis current value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-165526 ​​A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology disclosed in Patent Document 1, it is difficult to ensure the required driving force while raising the temperature of the battery while the electric vehicle is running, and there is a risk that unnecessary acceleration / deceleration will occur due to torque fluctuations.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide an electric vehicle that can achieve both raising the temperature of the battery and ensuring the required driving force while traveling. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, an electric vehicle according to the present invention is an electric vehicle including a first rotating electric machine for driving one of front wheels and rear wheels, a second rotating electric machine for driving the other of the front wheels and the rear wheels, a battery capable of supplying electric power to the first rotating electric machine and the second rotating electric machine, a coolant circulation circuit capable of recovering heat generated in the first rotating electric machine using a coolant and supplying the recovered heat to the battery, and a control device for controlling the drive of the first rotating electric machine and the second rotating electric machine, wherein the first rotating electric machine has a permanent magnet in a rotor core. The control device is a wound field motor in which a rotor coil is wound around a stator core without a rotor coil and a stator coil is wound around a stator core, and when it is necessary to warm up the battery during driving, the control device performs control such that, for the first rotating electric machine, no current is passed through the rotor coil but only through the stator coil, the heat generated by passing the current through the stator coil is recovered by the coolant in the coolant circulation circuit and supplied to the battery to warm up the battery, and the required driving force for driving is output by the second rotating electric machine.

[0007] This makes it possible to both increase the temperature of the battery and ensure the required driving force while the vehicle is traveling.

[0008] In the above, the second rotating electric machine may be a permanent magnet type motor in which a permanent magnet is provided in a rotor core and a stator coil is wound around a stator core.

[0009] This makes it possible to control the driving force by passing a current through the stator coil of the second rotating electric machine. Effect of the Invention

[0010] The electric vehicle according to the present invention has an advantage in that it is possible to both increase the temperature of the battery and ensure the required driving force while the vehicle is traveling. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an electric vehicle according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of a wound field motor according to an embodiment. [Diagram 3] FIG. 3 is a diagram showing an example of a schematic configuration of a coolant circulation circuit according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing an example of the control regarding the battery temperature increase and the driving force control executed by the electronic control device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electric vehicle according to the present invention will be described below. However, the present invention is not limited to the embodiment.

[0013] Fig. 1 is a diagram showing a schematic diagram of an electric vehicle 1 according to an embodiment. The electric vehicle 1 includes a wound field motor 2 which is a first rotating electric machine for driving front wheels 10, and a PM motor (permanent magnet motor) 3 which is a second rotating electric machine for driving rear wheels 20. In the wound field motor 2, a rotor coil is wound around a rotor core without providing a permanent magnet, and a stator coil is wound around a stator core. In the PM motor 3, a permanent magnet is provided in a rotor core, and a stator coil is wound around a stator core.

[0014] 2 is a diagram showing a schematic configuration of a wound field motor 2 according to an embodiment of the present invention. The wound field motor 2 according to the embodiment is made up of a rotor 210, a stator 220, and the like.

[0015] The rotor 210 is composed of a rotor core 211, a plurality of salient rotor poles 212 arranged along the circumferential direction of the rotor core 211, a rotor coil 213 wound around the salient rotor poles 212, and the like.

[0016] Rotor core 211 is an annular magnetic member having a plurality of rotor salient poles 212 arranged on the outer periphery and a shaft hole in the center to which shaft 230, which is a rotating shaft, is fixed.

[0017] The rotor coil 213 is a field coil wound around the salient rotor poles 212. The rotor coil 213 passes through the inside of a slot 214 formed between adjacent salient rotor poles 212 and is wound around the salient rotor poles 212 with a predetermined number of turns.

[0018] Stator 220 is composed of stator core 221, a plurality of teeth 222 arranged along the circumferential direction of stator core 221, and stator coils 223 wound a plurality of times around teeth 222. Although only a portion of stator 220 is shown in Fig. 2, annular stator 220 is provided so as to surround the entire circumference of rotor 210.

[0019] The stator core 221 is an annular magnetic member with a plurality of teeth 222 arranged on its inner periphery. The stator coil 223 includes a three-phase winding of a U-phase winding, a V-phase winding, and a W-phase winding. Each phase winding passes through slots 224, which are spaces between adjacent teeth 222, in order and is wound around a predetermined tooth 222 in accordance with a predetermined distributed winding arrangement method. The windings of the stator coil 223 wound around the teeth 222 are arranged in the circumferential direction of the stator core 221 in the order of the U-phase winding, the V-phase winding, and the W-phase winding, making one revolution.

[0020] Returning to Fig. 1, the electric vehicle 1 according to the embodiment includes a battery 5 which is an electricity storage device capable of supplying power to the wound field motor 2 and the PM motor 3. The wound field motor 2 is electrically connected to the battery 5 via a first inverter 4. The PM motor 3 is electrically connected to the battery 5 via a second inverter 6. The first inverter 4 and the second inverter 6 are controlled by an electronic control device 7, whereby the wound field motor 2 and the PM motor 3 can be made to function and operate as electric motors or generators.

[0021] In the electric vehicle 1, a first transaxle 8 that transmits the power (torque) output from the wound field motor 2 to front wheels 10, and a second transaxle 9 that transmits the power (torque) output from the PM motor 3 to rear wheels 20 are configured independently. The first transaxle 8 is configured by a first reduction gear, a first differential device, etc. The second transaxle 9 is configured by a second reduction gear, a second differential device, etc. The wound field motor 2 is connected to the front wheels 10 via the first transaxle 8 so as to be capable of transmitting power. The PM motor 3 is connected to the rear wheels 20 via the second transaxle 9 so as to be capable of transmitting power.

[0022] The electronic control device 7 selects whether to drive the wound field motor 2 or the PM motor 3 based on, for example, the required driving force determined by the amount of accelerator pedal depression (accelerator opening) and the vehicle speed, or based on whether or not control is performed regarding the temperature rise of the battery 5.

[0023] The electronic control device 7 controls the driving of the wound field motor 2 and the PM motor 3. The electronic control device 7 also controls the first inverter 4 and the second inverter 6 to control the driving of the wound field motor 2 and the PM motor 3. Furthermore, the electronic control device 7 performs control related to monitoring the state of the battery 5. A battery temperature sensor 51 that detects the temperature of the battery 5 is attached to the battery 5. The electronic control device 7 can perform, for example, control related to the temperature rise of the battery 5, which is included in the control related to monitoring the state of the battery 5, based on the detection result of the battery temperature sensor 51.

[0024] Fig. 3 is a diagram showing an example of a schematic configuration of a coolant circulation circuit 30 according to an embodiment. As shown in Fig. 3, the electric vehicle 1 according to the embodiment includes a coolant circulation circuit 30 for cooling the wound field motor 2 and controlling the temperature of the battery 5. In the coolant circulation circuit 30, a battery heat exchanger 31, a reserve tank 32, a heat exchanger 33, and a pump 34 are arranged in this order.

[0025] The battery heat exchanger 31 is provided on the battery 5 to exchange heat between the battery 5 and the coolant. The reserve tank 32 stores the coolant. The heat exchanger 33 is, for example, an air-cooled radiator, and cools the coolant. The pump 34 is, for example, an electric type, and circulates the coolant in the coolant circulation circuit 30 in the direction of the arrow in FIG. 3. Specifically, when the pump 34 operates, the coolant in the reserve tank 32 is supplied to the battery heat exchanger 31 via the heat exchanger 33. The coolant that has passed through the battery heat exchanger 31 returns to the reserve tank 32. The pump 34 is controlled by the electronic control device 7.

[0026] The coolant circulation circuit 30 is configured to include a flow path of the coolant for exchanging heat between the wound-field motor 2 and the coolant. In the coolant circulation circuit 30, the wound-field motor 2 is disposed between the outlet of the pump 34 and the inlet of the battery heat exchanger 31 in the flow direction of the coolant. As a result, heat generated in the wound-field motor 2 is collected by the coolant, and the wound-field motor 2 is cooled. The heat collected by the coolant is transferred to the battery heat exchanger 31 and supplied to the battery 5 via the battery heat exchanger 31. Note that the coolant circulation circuit 30 according to the embodiment is not limited to the configuration shown in FIG. 3 as long as it can transfer heat generated in the wound-field motor 2 to the battery 5. In addition, in the electric vehicle 1 according to the embodiment, a coolant circulation circuit having the same configuration as the coolant circulation circuit 30 and in which the PM motor 3 is disposed instead of the wound-field motor 2 may be provided for the PM motor 3, so that heat generated in the PM motor 3 can be transferred to the battery 5.

[0027] In the electric vehicle 1 according to the embodiment, when the temperature of the battery 5 is lower than a preset threshold temperature based on the detection result of the battery temperature sensor 51, control is performed regarding the temperature rise of the battery 5. Here, the wound field motor 2 is a magnetless motor, and a magnetic flux is generated by passing a current through the rotor coil 213 (field coil), and the driving force (torque) is controlled by the current passed through the stator coil 223. In other words, the wound field motor 2 does not output a driving force (torque) unless a current is passed through the rotor coil 213. Therefore, in the electric vehicle 1 according to the embodiment, when it is necessary to raise the temperature (warm up) of the battery 5 during traveling, a current is passed from the battery 5 to the wound field motor 2 via the first inverter 4 only through the stator coil 223 without passing a current through the rotor coil 213, and the heat generated by passing a current through the stator coil 223 is collected from the wound field motor 2 by the coolant in the coolant circulation circuit 30, supplied to the battery 5, and used to raise the temperature of the battery 5. At this time, a current is caused to flow from the battery 5 to the stator coil of the PM motor 3, causing the PM motor 3 to output a required driving force, thereby controlling the driving force during running.

[0028] Fig. 4 is a flowchart showing an example of the control relating to the battery temperature increase and the driving force control performed by the electronic control device 7 according to the embodiment. Note that the control shown in Fig. 4 is performed while the electric vehicle 1 is traveling.

[0029] First, the electronic control unit 7 acquires the temperature of the battery 5 detected by the battery temperature sensor 51 (step S1). Next, the electronic control unit 7 judges whether or not it is necessary to increase the temperature of the battery 5 (step S2). For example, when the electronic control unit 7 judges that the acquired temperature of the battery 5 is equal to or higher than a preset threshold temperature and that it is not necessary to increase the temperature of the battery 5 (No in step S2), the electronic control unit 7 ends the series of controls. On the other hand, when the electronic control unit 7 judges that the acquired temperature of the battery 5 is lower than the threshold temperature and that it is necessary to increase the temperature of the battery 5 (Yes in step S2), the electronic control unit 7 proceeds to step S3. In step S3, the electronic control unit 7 causes the wound-field motor 2 to pass a current from the battery 5 to the stator coil 223 without passing a current to the rotor coil 213, and recovers heat generated by passing a current to the stator coil 223 with the coolant in the coolant circulation circuit 30 and supplies it to the battery 5, thereby increasing the temperature of the battery 5 (step S3). Next, the electronic control unit 7 controls the driving force by causing a current to flow from the battery 5 to the stator coil of the PM motor 3, and outputting the required driving force for traveling from the PM motor 3 (step S4). After that, the electronic control unit 7 ends the series of controls.

[0030] In the electric vehicle 1 according to the embodiment, for example, by the electronic control device 7 implementing control relating to battery temperature increase and driving force control as shown in FIG. 4, it is possible to achieve both temperature increase of the battery 5 and securing of the required driving force while traveling.

[0031] In the above-described embodiment, the PM motor 3 is used as the second rotating electric machine for controlling the driving force during running, but the second rotating electric machine may also be a wound field motor like the first rotating electric machine. That is, in the electric vehicle 1 according to the embodiment, as long as a wound field motor is used as the first rotating electric machine for raising the temperature of the battery 5 during running, the type of the second rotating electric machine for controlling the driving force is not particularly limited.

[0032] 1, the electric vehicle 1 according to the embodiment described above is configured so that the front wheels 10 are driven by the wound field motor 2 which is the first rotating electric machine, and the rear wheels 20 are driven by the PM motor 3 which is the second rotating electric machine, but is not limited to this. That is, the electric vehicle 1 according to the embodiment may be configured so that the rear wheels 20 are driven by the wound field motor 2 which is the first rotating electric machine, and the front wheels 10 are driven by the PM motor 3 which is the second rotating electric machine motor. [Explanation of symbols]

[0033] 1 Electric vehicles Two-winding field motor 3 PM motor 4 First inverter 5 Battery 6 Second inverter 7 Electronic Control Unit 8 First transaxle 9. Second transaxle 10 Front wheel 20 Rear wheel 30 Coolant circulation circuit 31 Battery heat exchanger 32 Reserve tank 33 Heat exchanger 34 Pump 51 Battery Temperature Sensor 210 Rotor 211 Rotor core 212 rotor salient pole 213 Rotor coil 214 Slots 220 Stator 221 Stator core 222 Teeth 223 Stator coil 224 Slots 230 Shaft

Claims

1. a first rotating electric machine for driving one of the front wheels and the rear wheels; a second rotating electric machine for driving the other of the front wheels and the rear wheels; a battery capable of supplying electric power to the first rotating electric machine and the second rotating electric machine; a coolant circulation circuit capable of recovering heat generated by the first rotating electric machine using a coolant and supplying the recovered heat to the battery; a control device that controls driving of the first rotating electric machine and the second rotating electric machine; An electric vehicle comprising: the first rotating electric machine is a wound field motor in which a rotor coil is wound around a rotor core without a permanent magnet, and a stator coil is wound around a stator core, The control device includes: An electric vehicle characterized in that, when it is necessary to warm up the battery while traveling, a current is passed only through the stator coil of the first rotating electric machine without passing a current through the rotor coil, heat generated by passing a current through the stator coil is recovered by the coolant in the coolant circulation circuit and supplied to the battery to warm up the battery, and the required driving force for traveling is output by the second rotating electric machine.

2. 2. The electric vehicle according to claim 1, wherein the second rotating electric machine is a permanent magnet type motor in which a permanent magnet is provided in a rotor core and a stator coil is wound around a stator core.

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