Control device for a rotating electrical machine unit

Abstract

To secure insulation in a coil provided in a rotary electric machine by efficiently driving an oil pump.SOLUTION: A control device for a rotary electric machine unit controls the rotary electric machine unit including a rotary electric machine and an oil supply section including an oil pump for supplying oil to a coil included in the rotary electric machine. The control device includes: an information acquisition unit configured to acquire information on air density in the coil and information on a voltage applied to the rotary electric machine; an insulation determination unit configured to perform insulation determination in the coil based on the information on air density and the information of voltage acquired by the information acquisition unit; and a drive instruction unit configured to drive the oil supply section when the insulation determination unit determines that insulation of the coil is low and it is necessary to maintain the insulation state by supplying oil.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a control device for a rotating electrical machine unit.

Background Art

[0002] Conventionally, oil has been supplied to a coil provided in a motor as a rotating electrical machine using an oil pump (see, for example, Patent Document 1). In addition, a proposal has been made to supply oil as an insulating material in the coil (see, for example, Patent Document 2). The oil is supplied by an electric oil pump or a mechanical oil pump.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the oil pump is electric, power is consumed by the operation of the oil pump, and drive losses associated with pump drive occur, deteriorating the electricity cost. Also, even when the oil pump is mechanical, drive losses associated with pump drive occur. Therefore, in order to improve the electricity cost or reduce the drive losses associated with pump drive, it is desirable that the operating frequency of the oil pump be low. However, in Patent Document 2, there is room for improvement in ensuring insulation while reducing losses associated with pump drive.

[0005] Therefore, the invention disclosed in this specification aims to efficiently drive an oil pump and ensure insulation in a coil provided in a rotating electrical machine.

Means for Solving the Problems

[0006] The above problem is solved by a control device for a rotating electrical machine unit including a rotating electrical machine and an oil supply unit including an oil pump that supplies oil to a coil included in the rotating electrical machine. The control device includes an information acquisition unit that acquires information regarding the air density in the coil and information regarding the voltage applied to the rotating electrical machine, an insulation determination unit that determines whether or not insulation breakdown occurs in the coil based on the information regarding the air density and the information regarding the voltage acquired by the information acquisition unit, and a drive instruction unit that drives the oil supply unit when the insulation determination unit determines that insulation breakdown occurs in the coil and determines that it is necessary to maintain the insulation state by supplying oil.

[0007] In the control device for the rotating electrical machine unit having the above configuration, the information acquisition unit may acquire, as the information regarding the air density, information regarding the air temperature in the coil and information regarding the atmospheric pressure.

[0008] Also, in the control device for the rotating electrical machine unit having the above configuration, the information acquisition unit may acquire, as the information regarding the air temperature in the coil, the detected value of the temperature of the coil or the detected value of the temperature of the oil.

[0009] Furthermore, in the control device for the rotating electrical machine unit having the above configuration, the information acquisition unit may acquire, as the information regarding the atmospheric pressure, the detected value of an atmospheric pressure sensor or the altitude information acquired by a position information acquisition device included in a vehicle on which the rotating electrical machine is mounted.

[0010] In the control device of the rotating electrical machine unit having the above configuration, the oil pump is a mechanical pump driven by the operation of the internal combustion engine, and when the insulation determination unit determines that insulation breakdown has occurred in the coil and determines that it is necessary to maintain the insulation state by supplying oil, the drive instruction unit starts the internal combustion engine by driving the rotating electrical machine. When driving the rotating electrical machine to start the internal combustion engine based on the instruction of the drive instruction unit, an applied voltage limiting unit that limits the voltage applied to the rotating electrical machine can be further provided.

[0011] Another control device for a rotating electrical machine unit disclosed in this specification includes a rotating electrical machine and a gear mechanism driven by the rotating electrical machine, at least a part of which is immersed in oil. The control device for a rotating electrical machine unit includes an oil supply unit that supplies the oil to the coil provided in the rotating electrical machine when the gear mechanism operates, and an information acquisition unit that acquires information regarding the air density in the coil and information regarding the voltage applied to the rotating electrical machine. An insulation determination unit that determines whether insulation breakdown has occurred in the coil based on the information regarding the air density and the information regarding the voltage acquired by the information acquisition unit, and a drive instruction unit that drives the rotating electrical machine when the insulation determination unit determines that insulation breakdown has occurred in the coil and determines that it is necessary to maintain the insulation state by supplying oil, and an applied voltage limiting unit that limits the voltage applied to the rotating electrical machine when driving the rotating electrical machine according to the instruction of the drive instruction unit can be provided.

Advantages of the Invention

[0012] According to the invention disclosed in this specification, the oil pump can be efficiently driven to ensure the insulation of the coil provided in the rotating electrical machine.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

MODE FOR CARRYING OUT THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, in the drawings, the dimensions, ratios, etc. of each part may not be illustrated so as to be exactly the same as the actual ones. Also, depending on the drawings, details may be omitted.

[0015] (First Embodiment) [Vehicle] First, with reference to FIG. 1, a vehicle 20 equipped with a rotating electrical machine unit 100 according to the first embodiment will be described. The rotating electrical machine unit 100 includes a motor 30, which is an example of a rotating electrical machine, and an oil supply unit 60 that supplies oil to a coil (see FIG. 2) provided in the motor 30. The vehicle 20 also includes an ECU (Electronic Control Unit) 70 that performs various controls of the vehicle 20.

[0016] The vehicle 20 is an electric vehicle. The vehicle 20 includes a battery 58, which is a rechargeable secondary battery, a boost converter 57 that boosts the DC voltage of the battery, and an inverter 56. The inverter 56 switches the DC power source boosted by the boost converter 57 with switching elements and converts it into three-phase AC power. The three-phase AC power converted by the inverter 56 is supplied to the motor 30. The output shaft 22 of the motor 30 is transmitted to the drive wheels 26 via a differential gear 24, and the vehicle 20 is configured to be able to travel. Although the vehicle 20 of the present embodiment is an electric vehicle, as long as the motor 30 is used as a drive source, it may be a hybrid vehicle equipped with an engine. The motor 30 not only generates the driving force of the vehicle 20 in response to power supply from the battery 58, but can also function as a motor generator that generates electricity by power transmission from the drive wheels 26 of the vehicle 20 and charges the battery 58.

[0017] <Configuration of the Rotating Electrical Machine Unit> Here, the configuration of the rotating electrical machine unit 100 will be described in detail.

[0018] ≪Configuration of the Motor≫ First, with reference to FIGS. 2 and 3, the motor 30 will be described. The motor 30 includes a rotor 32 and a stator 40 housed in a case 46.

[0019] The stator 40 includes a stator core 42 which is a magnetic component generally in a cylindrical shape. The stator core 42 is formed, for example, by axially laminating magnetic plates such as electromagnetic steel sheets. A plurality of segment conductors are arranged in the stator core 42 to form a coil 44. The coil 44 includes a three-phase coil, that is, a U-phase coil, a V-phase coil, and a W-phase coil. Note that the coil 44 may be formed in a form wound around the teeth of the stator core 42 in a concentrated winding manner.

[0020] The rotor 32 includes a rotor core 34 which is concentric with the stator 40 on the radially inner side of the stator 40 and is arranged opposite to the stator 40. An output shaft 22 which is a rotating shaft member is provided at the central portion of the rotor core 34. The output shaft 22 is supported by bearings provided in the case 46 and a lid portion (not shown). Note that the rotor core 34 may be equipped with permanent magnets.

[0021] An oil supply port 46a into which oil supplied to the coil 44 by an oil supply portion 60 described later is introduced is provided at the upper portion of the case 46. Further, an oil discharge port 46b through which the oil supplied into the case 46 is discharged is provided at the lower portion of the case 46.

[0022] ≪Configuration of Oil Supply Portion≫ Next, the oil supply portion 60 will be described. The oil supply portion 60 includes an oil pan 62 provided at the lower portion of the motor 30, an oil supply pipe 66 in which an oil pump 64 is disposed, and an oil shower pipe 68 connected to the oil supply pipe 66. In FIGS. 2 and 3, the arrows indicate the flow of oil and the oil to be sprayed.

[0023] Oil is stored in the oil pan 62. The lower end portion of the oil supply pipe 66 is disposed in the oil pan 62, and when the oil pump 64 operates, the oil in the oil pan 62 is sucked up. An oil temperature sensor 82 described later is provided in the oil supply pipe 66. A heat exchanger for cooling the oil may be provided on the downstream side of the oil temperature sensor 82 of the oil supply portion 60.

[0024] The oil shower pipe 68 is disposed above the motor 30. The oil shower pipe 68 is connected to the oil supply pipe 66 and injects the oil pumped up by the oil pump 64 toward the motor 30. The oil injected from the oil shower pipe 68 is introduced into the case 46 through the oil supply port 46a. The oil introduced into the case 46 is supplied to the coil 44 housed in the case 46. The oil cools the coil 44 and functions as an insulating material for the coil 44, improving the insulation resistance of the coil 44.

[0025] The oil pump 64 in the present embodiment is electric and is driven based on a drive instruction from a drive instruction unit 70c (see FIG. 1), which will be described later.

[0026] <Configuration of the control unit> Next, the ECU 70 will be described. The ECU 70 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a storage device, etc. The ECU 70 controls the vehicle 20 by executing programs stored in the ROM and the storage device. The ECU 70 is electrically connected to the ignition 80, the coil temperature sensor 81, the oil temperature sensor 82, and the atmospheric pressure sensor 83. The ECU 70 is also electrically connected to the GPS (Global Positioning System) altitude information acquisition unit 84 and the voltage sensor 85. The ECU 70 is further electrically connected to the SOC (State Of Charge) sensor 59 connected to the battery 58. In addition to these, various sensors for controlling the vehicle 20 are electrically connected to the ECU 70, but detailed descriptions of these are omitted here.

[0027] Ignition 80 is a switch for making the vehicle 20 drivable. The coil temperature sensor 81 is installed near the coil 44 and detects the temperature of the coil 44. The oil temperature sensor 82 detects the temperature of the oil supplied to the coil 44. The atmospheric pressure sensor 83 detects the atmospheric pressure of the environment where the vehicle 20 is located. The GPS altitude information acquisition unit 84 extracts altitude information from the position information detected by the position information detection unit provided in the car navigation system (position information acquisition device). The voltage sensor 85 detects the voltage boosted by the boost converter 57. The SOC sensor 59 detects the remaining capacity SOC of the battery 58.

[0028] The ECU 70 determines whether the motor 30 is placed in an environment where oil supply is required as an insulating material. When oil supply is required, the ECU 70 drives the oil pump 64 and executes control to supply oil to the coil 44. To execute such control, the ECU 70 functions as an information acquisition unit 70a, an insulation determination unit 70b, and a drive instruction unit 70c.

[0029] The insulation determination unit 70b determines whether insulation breakdown, that is, a short circuit, occurs in the coil 44. Here, the determination of whether insulation breakdown occurs includes not only the case where insulation breakdown actually occurs but also the case where there is a possibility of insulation breakdown. The threshold value for determining whether insulation breakdown occurs can be set through experiments, simulations, etc. The information acquisition unit 70a acquires various information for the insulation determination unit 70b to determine the insulation performance of the coil 44. The drive instruction unit 70c drives the oil pump 64 when the insulation determination unit 70b determines that oil supply to the coil 44 is necessary.

[0030] Here, information for determining the insulation of the coil 44 will be described. The insulation of the coil 44 is affected by the air density inside the coil 44, that is, the air density between the wire materials such as the segment conductors and windings forming the coil 44, and the voltage applied to the coil 44. Specifically, when the air density decreases and the voltage applied to the coil 44 increases, the insulation deteriorates. Therefore, in the present embodiment, information on the air density and information on the voltage (motor applied voltage) applied to the motor 30 (coil 44) are acquired, and the insulation is determined based on this information.

[0031] The air density is affected by the air temperature and the atmospheric pressure. Therefore, in the present embodiment, in order to consider the influence of the air density, the information acquisition unit 70a acquires information on the air temperature and information on the atmospheric pressure.

[0032] Since it is difficult to directly detect the air temperature inside the coil 44, in the present embodiment, the coil temperature having a correlation with the air temperature is detected and used as the air temperature. The coil temperature is detected by the coil temperature sensor 81. Note that, as a value having a correlation with the air temperature, the oil temperature detected by the oil temperature sensor 82 may be acquired as information. Further, in the vehicle 20, a heat circuit network in which heat is exchanged at various locations is formed. Therefore, the temperature estimated based on the heat exchange in this heat circuit network can also be used as information on a value having a correlation with the air temperature.

[0033] The atmospheric pressure is detected by the atmospheric pressure sensor 83 provided in the vehicle 20. Note that, in a vehicle equipped with a navigation system such as the vehicle 20 of the present embodiment, the atmospheric pressure estimated based on the altitude information extracted from the position information detected by the position information detection device may be used as information.

[0034] The voltage applied to the motor 30 is detected by a voltage sensor 85 that detects the voltage boosted by the boost converter 57. Note that, if it is a value that can evaluate the voltage applied to the motor 30, the voltage at other locations in the vehicle 20 may be adopted as information. For example, the voltage that can be applied to the motor 30 may be estimated based on the state of charge SOC of the battery 58 detected by the SOC sensor 59, and this value may be adopted as information. Further, if the vehicle does not have a boosting system such as the boost converter 57, the voltage of the battery 58 may be adopted as information. Further, in the vehicle 20, a surge voltage may occur for various reasons, and when the occurrence of the surge voltage is predicted, the predicted surge voltage may be adopted as information. Thereby, the motor 30 can be protected.

[0035] [Oil Supply Control] Next, an example of oil supply control will be described with reference to FIGS. 1, 4, and 5.

[0036] The ECU 70 determines whether the ignition 80 is turned on in step S1. When the ECU 70 makes an affirmative determination (Yes determination) in step S1, it proceeds to step S2. On the other hand, when the ECU 70 makes a negative determination (No determination) in step S1, it repeats the process of step S1 until an affirmative determination is made in step S1.

[0037] In step S2, the ECU 70, specifically, the information acquisition unit 70a acquires various information for determining whether the insulation in the coil 44 (see FIG. 2) is ensured. That is, the information acquisition unit 70a acquires the coil temperature as the air temperature inside the coil from the coil temperature sensor 81, and acquires the atmospheric pressure as the air pressure inside the coil from the atmospheric pressure sensor 83. Further, the information acquisition unit 70a acquires the voltage boosted by the boost converter 57 from the voltage sensor 85 as the motor applied voltage.

[0038] In step S3, which is executed following step 2, the insulation determination unit 70b determines the insulation property of the coil 44. The insulation determination unit 70b performs insulation determination based on the oil pump operation map shown in FIG. 5. When a negative determination is made in step S3, that is, when it is determined that the insulation property of the coil 44 cannot be ensured, the process proceeds to step S4. In step S4, the drive instruction unit 70c gives a drive instruction for the oil pump 64. On the other hand, when the insulation determination unit 70b makes an affirmative determination in step S3, the ECU 70 repeats the process from step S1.

[0039] Here, the oil pump operation map shown in FIG. 5 will be described. The oil pump operation map is composed of three parameters: the motor applied voltage (denoted as "voltage" in the map) applied to the motor 30, the coil temperature, and the altitude. Specifically, the insulation property is determined based on the combination of the coil temperature and altitude set for each voltage, and based on the result, it is determined whether to operate the oil pump 64 or not. In FIG. 5, the hatched portion indicates a state where the insulation property cannot be ensured and it is determined to operate the oil pump 64.

[0040] The higher the value of the motor applied voltage, the more difficult it is to ensure the insulation property. Also, the higher the coil temperature (the air temperature inside the coil) and the altitude, the lower the air density and the more difficult it is to ensure the insulation property. For this reason, in the oil pump operation map, the higher the motor applied voltage, the higher the frequency of operating the motor 30. That is, even when the coil temperature and altitude are the same, the higher the motor applied voltage, the higher the frequency of operating the motor. For this reason, even when the coil temperature is low and the altitude is low, that is, when the air density is high, the frequency of operating the motor 30 is high. Also, even when the motor applied voltage and altitude are the same, the higher the coil temperature, the higher the frequency of operating the motor. Also, even when the motor applied voltage and coil temperature are the same, the higher the altitude, the higher the frequency of operating the motor.

[0041] When the insulation determination unit 70b makes a negative determination in step S3, it proceeds to step S4 and starts driving the oil pump 64. Then, it proceeds to step S5. In step S5, the ECU 70 determines whether t seconds have elapsed since the start of driving the oil pump 64. This t seconds is a time set in advance through experiments or simulations as the oil supply time for operating the oil pump 64 and improving the insulation resistance of the coil 44. When the ECU 7 makes an affirmative determination in step S5, it proceeds to step S6 and stops driving the oil pump 64. On the other hand, when the ECU 70 makes a negative determination in step S5, it repeats the process of step S5 until an affirmative determination is made in step S5 and continues driving the oil pump 64.

[0042] In step S7, which is executed subsequent to step S6, the ECU 70 determines whether the ignition 80 has been turned off. When the ECU 70 makes a negative determination in step S7, it repeats the process from step S1. Thereby, when the ignition 80 is in the on state, the oil supply control continues. On the other hand, when the ECU 70 makes an affirmative determination in step S7, it ends the series of processes (ends).

[0043] As described above, according to the present embodiment, when the insulation determination unit 70b determines that oil supply to the coil 44 is necessary, the oil pump 64 is driven and oil is supplied to the coil. In this way, since the driving of the oil pump 64 is executed based on the insulation determination of the insulation determination unit 70b, the operating frequency of the oil pump can be suppressed. Also, the insulation resistance in the coil 44 can be improved and the insulation property in the coil 44 can be ensured.

[0044] (Second Embodiment) [Rotating Electric Machine Unit in Hybrid Vehicle] Next, referring to FIG. 6, the second embodiment will be described. The vehicle 120 of the second embodiment is a hybrid vehicle equipped with an engine 122. That is, the second embodiment is an embodiment in which the vehicle 120, which is a hybrid vehicle, is provided with a rotary electric machine unit 200. For the common components of the first embodiment, the same reference numerals are given in the drawings, and the detailed description thereof is omitted.

[0045] The vehicle 120 includes, together with the engine 122, a first motor generator 130, a second motor generator 230, and a power split device 124. The output from the engine 122 is split by the power split device 124, which is a planetary gear mechanism, into power for driving the vehicle and power for power generation. The first motor generator 130 normally functions as a generator, and the second motor generator 230 normally functions as a motor. Then, the power from the engine 122 and the output from the second motor generator 230 together rotate drive wheels (not shown) to make the vehicle 120 run. The second motor generator 230 is a synchronous motor driven by three-phase AC power converted by an inverter 56 after the DC power of the battery 58, which is a rechargeable secondary battery, is boosted by a boost converter 57. Also, the three-phase AC power generated by the first motor generator 130 is converted into DC power by an inverter 156 and stored in the battery 58.

[0046] The first motor generator 130 and the second motor generator 230 each correspond to a rotary electric machine, and their configurations are generally common to the motor 30 in the first embodiment.

[0047] Vehicle 120 includes an oil supply unit 160 instead of the oil supply unit 60 included in vehicle 20 of the first embodiment. The oil supply unit 160 includes an oil pan 162 provided below the engine 122, the first motor generator 130, the power split device 124, and the second motor generator 230, and an oil supply pipe 166 in which an oil pump 164 is disposed. Further, although omitted in FIG. 6, the oil supply unit 160 includes an oil shower pipe connected to the oil supply pipe 166. The oil shower pipe supplies oil to the first motor generator 130 and the second motor generator 230.

[0048] Here, unlike the oil pump 64 in the first embodiment, the oil pump 164 is a mechanical pump driven by the rotation of the engine 122. The oil pump 164 is rotationally driven by a camshaft (not shown) provided in the engine 122.

[0049] Also in such a vehicle 120, oil supply control is executed in the same manner as in the first embodiment. That is, the control based on the flowchart shown in FIG. 4 can also be applied in the second embodiment. However, since the oil pump 164 in the present embodiment is mechanical, in step S4 in the flowchart shown in FIG. 4, the engine 122 is started. That is, the ECU 70 starts the engine 122 and rotates the camshaft provided in the engine 122 to drive the oil pump 164. Thereby, similar to the first embodiment, the insulation resistance in the first motor generator 130 and the second motor generator 230 can be improved.

[0050] Also in the second embodiment, since the driving of the oil pump 164 is executed based on the insulation determination by the insulation determination unit 70b, the operation frequency of the oil pump can be suppressed.

[0051] When the engine 122 is provided with an intake pressure sensor, the atmospheric pressure may be estimated based on the detection value of this intake pressure sensor, and this estimated value may be used for the determination of the insulation property in the coil.

[0052] (Third Embodiment) Next, with reference to FIGS. 7 to 9, the third embodiment will be described. The hardware configuration of the vehicle 220 in the third embodiment is common to that of the vehicle 120 in the second embodiment, but the ECU 70 differs from the second embodiment in that in addition to the information acquisition unit 70a, the insulation determination unit 70b, and the drive instruction unit 70c, it functions as an applied voltage limitation unit 70d. The same reference numerals as those in the second embodiment are assigned to the components common to the second embodiment. A detailed description of the components common to the second embodiment is omitted.

[0053] The output shaft 122a of the engine 122 provided in the vehicle 220 is connected to a first motor generator 130 corresponding to a rotating electrical machine. The engine 122 can be started by driving the first motor generator 130.

[0054] The first motor generator 130 is driven based on an instruction from the drive instruction unit 70c to start the engine 122. At this time, the applied voltage limitation unit 70d limits the voltage applied to the first motor generator 130.

[0055] When the drive instruction unit 70c starts the engine 122 and starts driving the mechanical oil pump 164, it is when there is a possibility of insulation breakdown occurring in the first motor generator 130. At this time, if the first motor generator 130 is driven without limiting the applied voltage, there is a possibility of insulation breakdown occurring in the first motor generator 130. Therefore, the applied voltage limitation unit 70d limits the voltage applied to the first motor generator 130.

[0056] Here, with reference to the flowchart shown in FIG. 8, an example of oil supply control in the third embodiment will be described. Steps S1 to S3 and step S7 in the flowchart shown in FIG. 8 are common to the flowchart shown in FIG. 4, that is, the oil supply control in the first embodiment. Therefore, the description of steps S1 to S3 and step S7 is omitted.

[0057] In the oil supply control according to the third embodiment, in step S31, the applied voltage limiting unit 70d limits the motor applied voltage. The limitation of the motor applied voltage is implemented based on the map shown in FIG. 9. The map shown in FIG. 9 is a map for setting the output torque. The output torque is represented as a ratio to the full load torque in the first motor generator 130. The output torque may also be referred to as the load factor of the first motor generator 130. The limit value of the output torque is set by the combination of the coil temperature in the first motor generator 130 and the altitude of the vehicle 220 mapped in this map. The limitation of the output torque becomes larger as the altitude at which the vehicle 220 is located is higher and as the coil temperature is higher. The applied voltage limiting unit 70d limits the applied voltage of the first motor generator 130 based on the set limit value of the output torque. The first motor generator 130 starts the engine 122 by being driven at the limited voltage.

[0058] The ECU 70 drives the first motor generator 130 in step S41, which is carried out subsequent to step S31, to start the engine 122. When the engine 122 starts, the oil pump 164 is driven. Thereby, the supply of oil to the first motor generator 130 is started.

[0059] In step S51, the ECU 70 determines whether or not the oil supply amount sufficient to avoid dielectric breakdown has been achieved. The oil supply amount can be determined, for example, by the combination of the rotational speed of the engine 122 and the operating time of the engine 122. If the rotational speed of the engine 122 is high, the predetermined oil supply amount can be reached even if the operating time is short. On the contrary, if the rotational speed of the engine 122 is low, the operating time until the required oil supply amount is reached becomes long. When the ECU 70 makes a negative determination in step S51, the process of step S51 is repeated until a positive determination is made in step S51. On the other hand, when the ECU 70 makes a positive determination in step S51, it proceeds to step S61.

[0060] In step S61, the ECU 70 releases the applied voltage limit of the first motor generator 130. As a result, the first motor generator 130 can drive the vehicle 220 without being limited by the applied voltage.

[0061] Subsequent to step S61, the ECU 70 proceeds to step S7.

[0062] Similar to the second embodiment, the third embodiment can improve the insulation resistance in the first motor generator 130 and the second motor generator 230. Also, by limiting the applied voltage when starting the engine 122, insulation breakdown can be more reliably avoided.

[0063] (Fourth Embodiment) Next, with reference to FIGS. 10 and 11, the fourth embodiment will be described. The rotating electrical machine unit 300 of the fourth embodiment includes MG1 and MG2, that is, the first motor generator 131 and the second motor generator 231. The first motor generator 131 and the second motor generator 231 form a drive device 90 together with a gear mechanism 150. The first motor generator 131, the second motor generator 231, and the gear mechanism 150 are provided in a case 91. The rotating electrical machine unit 300 includes components common to the third embodiment. The same reference numerals as those in the third embodiment are assigned to the common components. A detailed description of the components common to the third embodiment is omitted. Hereinafter, the configuration of the drive device 90 will be described, and an example of oil supply control in the rotating electrical machine unit 300 will be described.

[0064] The drive device 90 includes a case 91. Inside the case 91, an input shaft 92, an MG shaft 93, a differential shaft 94, and a counter shaft 95 are arranged. The input shaft 92 is coaxially connected to the output shaft of an engine (not shown in the fourth embodiment). Inside the case 91, a first motor generator 131 arranged coaxially with the input shaft 92 and a second motor generator 231 arranged coaxially with the MG shaft 93 are provided.

[0065] The MG shaft 93 is the input / output shaft of the second motor generator 231. Torque is transmitted between the input shaft 92 and the MG shaft 93 via a gear 97 of the input shaft 92 and a gear 98 of the MG shaft 93. Also, the rotation of the input shaft 92 is transmitted from the gear 97 of the input shaft 92 to the gear 99 of the counter shaft 95, and further from the gear 102 of the counter shaft 95 to the differential ring gear (rotating member) 101 of the differential shaft 94. The rotation of the differential shaft 94 is transmitted to the drive wheels of the vehicle via a differential device (not shown).

[0066] In the drive device 90, the oil scraped up by the differential ring gear 101 is supplied to each part of the drive device 90, thereby lubricating and cooling each part of the drive device 90. Also, insulation breakdown in the first motor generator 131 and the second motor generator 231 is avoided accordingly.

[0067] An oil sump 110 is provided at the lower part of the case 91. An oil catch tank 111 is formed at the upper part of the case 90. The oil catch tank 111 is provided above the differential ring gear 101. The differential ring gear 101 is provided such that its lower part is located below the liquid level Lv of the oil stored in the oil sump 110. When the differential ring gear 101 rotates in conjunction with the running (forward movement) of the vehicle, the oil in the oil sump 110 is scraped up by the differential ring gear 101 and sent to the oil catch tank 111 as shown by the arrow 1a.

[0068] The lubricating oil sent to the oil catch tank 111 drips from the oil catch tank 111 toward the first motor generator 131 and the second motor generator 231 as indicated by the arrow 1b.

[0069] This avoids dielectric breakdown in the first motor generator 131 and the second motor generator 231.

[0070] In this embodiment, the first motor generator 131 and the second motor generator 231 are provided. However, the drive device may be in a so-called one-motor type in which only one motor generator is provided. Also, in this embodiment, the engine is not essential, and the vehicle may be an electric vehicle.

[0071] Here, with reference to the flowchart shown in FIG. 11, an example of oil supply control in the fourth embodiment will be described. Steps S1 to S3 and step S7 in the flowchart shown in FIG. 11 are common to the flowchart shown in FIG. 4, that is, the oil supply control in the first embodiment. Therefore, the description of steps S1 to S3 and step S7 is omitted.

[0072] Comparing the flowchart of this embodiment shown in FIG. 11 with the flowchart of the third embodiment shown in FIG. 8, in this embodiment, steps S32 and S62 are implemented instead of steps S31 and S61 in the third embodiment. This is because in the third embodiment, the object of the applied voltage limit was only the first motor generator 130, but in this embodiment, both the first motor generator 131 and the second motor generator 231 are the objects of the applied voltage limit. Since the applied voltage in step S32 can be set in the same manner as in step S31, the detailed description thereof is omitted here.

[0073] In this embodiment, the process corresponding to step S41 in the third embodiment is not set. Also, in step S51, the point of determining whether the oil supply amount is sufficient is common to this embodiment and the third embodiment. However, in this embodiment, the determination of whether the oil supply amount is sufficient is performed based on the combination of the vehicle speed and its duration.

[0074] In the fourth embodiment, the oil supply is carried out by scooping up with a gear. Therefore, it is not essential for the system to include an oil pump, and there is no problem with the electricity cost and drive loss associated with driving the oil pump. However, even in a system without an oil pump, by limiting the applied voltage to drive the rotating electrical machine as in this embodiment, it is possible to avoid the occurrence of dielectric breakdown when the rotating electrical machine is driven.

[0075] The above embodiments are merely examples for implementing the present invention, and the present invention is not limited thereto. Modifying these examples variously is within the scope of the present invention, and it is obvious from the above description that various other embodiments are possible within the scope of the present invention.

Explanation of Reference Numerals

[0076] 20 Vehicle, 30 Motor, 32 Rotor, 34 Rotor Core, 40 Stator, 42 Stator Core, 44 Coil, 46 Case, 46a Oil Supply Port, 46b Oil Drain Port, 56 Inverter, 57 Boost Converter, 58 Battery, 59 SOC Sensor, 60, 160 Oil Supply Unit, 62, 162 Oil Pan, 64, 164 Oil Pump, 66 Oil Supply Pipe, 68 Oil Shower Pipe, 70 ECU, 70a Information Acquisition Unit, 70b Insulation Determination Unit, 70c Drive Instruction Unit, 80 Ignition, 81 Coil Temperature Sensor, 82 Oil Temperature Sensor, 83 Atmospheric Pressure Sensor, 84 GPS Altitude Information Acquisition Unit, 85 Voltage Sensor, 100, 200, 300 Rotating Electrical Machine Unit

Claims

1. A control device for a rotating electrical machine unit, comprising: a rotating electrical machine; and an oil supply unit including an oil pump that supplies oil to a coil provided in the rotating electrical machine, the control device including: an information acquisition unit that acquires information regarding the air density in the coil and information regarding the voltage applied to the rotating electrical machine; an insulation determination unit that determines whether or not insulation breakdown occurs in the coil based on the information regarding the air density and the information regarding the voltage acquired by the information acquisition unit; a drive instruction unit that drives the oil supply unit when the insulation determination unit determines that insulation breakdown occurs in the coil and determines that it is necessary to maintain the insulation state by supplying oil; and a control device for a rotating electrical machine unit.

2. The information acquisition unit acquires, as the information regarding the air density, information regarding the air temperature in the coil and information regarding the atmospheric pressure. The control device for a rotating electrical machine unit according to claim 1.

3. The information acquisition unit acquires, as the information regarding the air temperature in the coil, a detected value of the temperature of the coil or a detected value of the temperature of the oil. The control device for a rotating electrical machine unit according to claim 2.

4. The information acquisition unit acquires, as the information regarding the atmospheric pressure, a detected value of an atmospheric pressure sensor or altitude information acquired by a position information acquisition device provided in a vehicle on which the rotating electrical machine is mounted. The control device for a rotating electrical machine unit according to claim 2.

5. The oil pump is a mechanical pump driven by the operation of an internal combustion engine, and when the insulation determination unit determines that insulation breakdown occurs in the coil and determines that it is necessary to maintain the insulation state by supplying oil, the drive instruction unit drives the rotating electrical machine to start the internal combustion engine. The control device for a rotating electrical machine unit according to claim 1, further comprising an applied voltage limitation unit that limits the voltage applied to the rotating electrical machine when driving the rotating electrical machine to start the internal combustion engine based on an instruction from the drive instruction unit. The control device for a rotating electrical machine unit according to claim 1.

6. A control device for a rotating electrical machine unit, comprising: a rotating electrical machine; and an oil supply unit that is driven by the rotating electrical machine and includes a gear mechanism at least partially immersed in oil, and supplies the oil to a coil provided in the rotating electrical machine when the gear mechanism operates. An information acquisition unit that acquires information regarding the air density in the coil and information regarding the voltage applied to the rotating electrical machine; An insulation determination unit that determines whether or not insulation breakdown occurs in the coil based on the information regarding the air density and the information regarding the voltage acquired by the information acquisition unit; A drive instruction unit that drives the rotating electrical machine when the insulation determination unit determines that insulation breakdown occurs in the coil and determines that it is necessary to maintain the insulation state by supplying oil; An applied voltage limiting unit that limits the voltage applied to the rotating electrical machine when driving the rotating electrical machine according to the instruction of the drive instruction unit; Comprising A control device for a rotating electrical machine unit.

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