JP6421520B2 - Control device - Google Patents

Description

  The present invention relates to a control device for a rotating electrical machine.

  2. Description of the Related Art Conventionally, a control device that controls a power conversion device that converts power supplied to a motor is known. For example, in Patent Document 1, overheating is prevented by limiting the torque command value when the temperature of an IGBT (insulated gate bipolar transistor) constituting the inverter reaches a limit temperature.

Japanese Patent Laid-Open No. 7-194094

By the way, for example, IGBTs constituting an inverter have different thermal resistances depending on the degree of thermal degradation. However, in Patent Document 1, no consideration is given to the degree of deterioration of the IGBT. Therefore, for example, if torque limiting processing is performed assuming an average degree of thermal degradation, torque limitation is excessively applied in the initial stage where thermal degradation is small. In addition, when the thermal deterioration is large, there is a risk that thermal destruction will occur before the torque limiting process is performed.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a control device that appropriately controls a rotating electrical machine in accordance with a deterioration state of a circuit unit.

The control device of the present invention includes pre-energization temperature acquisition means, post-energization temperature acquisition means, deterioration state determination means, storage means, and torque limiting means.
The pre-energization temperature acquisition means acquires a pre-energization temperature that is the temperature of the circuit unit before energizing the circuit unit including the switching element related to switching of energization of the rotating electrical machine.
Temperature obtaining means after power is energizing the circuit portion in a state where the driving force is not reached transfer between the rotary electric machine and other devices by turning off the clutch provided between the rotary electric machine and other devices To obtain the post-energization temperature, which is the temperature of the circuit portion after the predetermined energy is input.

The deterioration state determination means determines the deterioration state of the circuit unit based on a temperature increase value that is a difference between the post-energization temperature and the pre-energization temperature.
The torque limiting means limits the torque output from the rotating electrical machine based on the deterioration state and the temperature of the circuit unit.
At least one of the limit start temperature, which is the temperature of the circuit unit that starts the torque limit, and the torque limit slope according to the temperature of the circuit unit is variable depending on the deterioration state.

  In the present invention, the deterioration state is determined based on the temperature rise value of the circuit unit when predetermined energy is supplied by energizing the circuit unit in a state where the driving force of the rotating electrical machine is not transmitted to the drive wheels. Thereby, the deterioration state of a circuit part can be determined appropriately, without being influenced by the temperature change of the rotary electric machine accompanying transmission of a driving force.

  In addition, since at least one of the restriction start temperature for starting torque restriction and the torque restriction gradient is variable according to the deterioration state, the rotating electrical machine can be appropriately controlled according to the deterioration state of the circuit unit. Thereby, it is possible to avoid excessive torque limitation in a state where the deterioration of the circuit portion is small. Further, since the torque can be quickly limited in a state in which the circuit portion is greatly deteriorated, further thermal deterioration of the circuit portion can be suppressed and damage to the circuit portion can be prevented.

It is a schematic structure figure showing the composition of the vehicle control system by one embodiment of the present invention. It is a block diagram explaining the circuit part and control part by one Embodiment of this invention. It is a typical side view showing a power card by one embodiment of the present invention. It is a flowchart explaining the degradation state determination process by one Embodiment of this invention. It is explanatory drawing explaining the change of the temperature rise value according to the degradation state by one Embodiment of this invention. It is explanatory drawing explaining the determination method of the degradation state by one Embodiment of this invention. It is explanatory drawing explaining the torque limitation map by one Embodiment of this invention. It is a flowchart explaining the torque limiting process by one Embodiment of this invention. It is a time chart explaining the torque limiting process by one Embodiment of this invention.

Hereinafter, a control apparatus according to the present invention will be described with reference to the drawings.
(One embodiment)
FIG. 1 shows a vehicle control system to which a control device according to an embodiment of the present invention is applied.
As shown in FIG. 1, the vehicle control system 1 includes an engine 11, a motor generator 12 as a rotating electric machine, a transmission 13, a battery 15 as a power source, a first clutch 16, a second clutch 17, a circuit unit 20, and A control unit 50 and the like are provided and mounted on the vehicle 90. The vehicle 90 of this embodiment is a hybrid vehicle that travels with the driving force of the engine 11 and the MG 12.
Hereinafter, the motor generator is referred to as “MG” as appropriate.

The engine 11 is an internal combustion engine having a plurality of cylinders, and the driving force of the engine 11 is transmitted to the motor generator 12 via the first clutch 16.
The motor generator 12 has a function as an electric motor that generates torque by being driven by electric power from the battery 15 and a function as a generator that is driven by the engine 11 or driven when the vehicle 90 is braked to generate electric power. . The motor generator 12 of this embodiment is a permanent magnet type synchronous three-phase AC motor. Hereinafter, the case where the motor generator 12 functions as an electric motor will be mainly described.

  Driving forces of the engine 11 and the motor generator 12 are transmitted to the drive shaft 91 via the second clutch 17 and the transmission 13. The driving force transmitted to the driving shaft 91 rotates the driving wheel 95 as a driving target via the gear 92 and the axle 93. The transmission 13 of the present embodiment is a continuously variable transmission (CVT) capable of continuously changing gears, but may be a stepped transmission.

The battery 15 is a direct current power source constituted by a rechargeable secondary battery such as nickel hydride or lithium ion. Instead of the battery 15, a power storage device such as an electric double layer capacitor may be used as a DC power source.
The battery 15 is controlled so that SOC (State Of Charge) as a charged state is within a predetermined range.

The first clutch 16 is provided between the engine 11 and the motor generator 12, and is configured to be able to connect and disconnect the engine 11 and the motor generator 12.
The second clutch 17 is provided between the motor generator 12 and the transmission 13 and is configured to be able to connect and disconnect the motor generator 12 and the transmission 13.
That is, when the first clutch 16 is disengaged, the driving force of the engine 11 is not transmitted to the motor generator 12 side, and when the second clutch 17 is disengaged, the driving force of the motor generator 12 is not transmitted to the drive wheel 95 side. .

Details of the circuit unit 20 and the control unit 50 are shown in FIG. In FIG. 2, the control lines are omitted as appropriate.
As shown in FIG. 2, the circuit unit 20 includes a boost converter 21 and an inverter unit 30.
Boost converter 21 includes a reactor 22, a boost drive unit 23, a capacitor 26, and the like.
Reactor 22 generates an induced voltage with changes in reactor current IL, and accumulates electric energy.

  The step-up drive unit 23 includes a high potential side switching element (hereinafter, the switching element is referred to as “SW element”) 24 and a low potential side SW element 25. Both the high potential side SW element 24 and the low potential side SW element 25 are IGBTs. The high potential side SW element 24 has a collector connected to the high potential line 37 of the inverter unit 30 and an emitter connected to the collector of the low potential side SW element 25. The emitter of the low potential side SW element 25 is connected to the low potential line 38 of the inverter unit 30. An output terminal of the reactor 22 is connected to a connection point between the high potential side SW element 24 and the low potential side SW element 25.

The SW elements 24 and 25 are turned on and off alternately and complementarily based on the converter drive signal from the control unit 50. When the high potential side SW element 24 is off and the low potential side SW element 25 is on, the reactor current IL flows through the reactor 22, whereby energy is accumulated in the reactor 22. Further, when the high potential side SW element 24 is on and the low potential side SW element 25 is off, the energy accumulated in the reactor 22 is released, so that an output is boosted by superimposing an induced voltage on the battery input voltage Vin. The voltage is charged in the capacitor 26.
The capacitor 26 is connected in parallel with the inverter unit 30.

  The inverter unit 30 is a three-phase inverter having six SW elements 31 to 36, and includes a power card 40 (see FIG. 3). The SW elements 31 to 36 of the present embodiment are all IGBTs, the high potential side SW elements 31 to 33 are disposed on the high potential side, and the low potential side SW elements 34 to 36 are disposed on the low potential side.

The collectors of the high potential side SW elements 31 to 33 are connected to the high potential line 37. The emitter of the high potential side SW element 31 is connected to the collector of the low potential side SW element 34, the emitter of the high potential side SW element 32 is connected to the collector of the low potential side SW element 35, and the emitter of the high potential side SW element 33. Is connected to the collector of the low potential side SW element 36. The emitters of the low potential side SW elements 34 to 36 are connected to the low potential line 38.
A connection point between high potential side SW elements 31 to 33 and low potential side SW elements 34 to 36 is connected to one end of each phase winding (U phase, V phase, W phase) of motor generator 12.

The high potential side SW elements 31 to 33 and the low potential side SW elements 34 to 36 that are paired are alternately and complementarily turned on and off based on the inverter drive signal from the control unit 50.
DC power of the output voltage boosted by the boost converter 21 is input to the inverter unit 30, and the DC power is converted into three-phase AC power by turning on and off the SW elements 31 to 36 and output to the motor generator 12. .

As shown in FIG. 3, the power card 40 includes SW elements 31 to 36, a power card substrate 41, a heat radiating plate 42, and heat radiating grease 43. In FIG. 3, the SW element 31 is illustrated and the description of the SW elements 32 to 36 is omitted.
The SW elements 31 to 36 are mounted on the power card substrate 41. A heat radiating plate 42 is provided on the surface of the SW elements 31 to 36 opposite to the power card substrate 41. A heat radiation grease 43 is applied between the SW elements 31 to 36 and the heat radiation plate 42. Thereby, the heat of the SW elements 31 to 36 is radiated from both the power card substrate 41 side and the heat radiating plate 42 side.
The entire power card 40 is cooled by cooling water flowing through a cooling pipe (not shown).

As shown in FIG. 2, the control unit 50 includes an MG control unit (described as “MG-ECU” in the drawing) 51 as a control device, and a hybrid control unit (in the drawing, “HV-ECU”). Described.) 55.
The MG control unit 51 includes a calculation unit 52 and a storage unit 53.

  The calculation unit 52 is configured mainly by a microcomputer including a CPU, a ROM, a RAM, and the like, and executes various controls by executing various control programs stored in the ROM. The arithmetic unit 52 controls the drive of the boost converter 21 by generating a converter drive signal and outputting it to the boost converter 21.

The calculation unit 52 acquires the temperatures of the SW elements 31 to 36 from a temperature sensor (not shown). The element temperature T may be the temperature itself of some or all of the SW elements 31 to 36, or may be an average value or the like.
The computing unit 52 determines the deterioration state of the SW elements 31 to 36 based on the element temperature T that is the acquired temperature of the SW elements 31 to 36. Details of the deterioration state determination will be described later. The arithmetic unit 52 controls the driving of the motor generator 12 by generating an inverter drive signal corresponding to the torque command value trq ^* and the deterioration state from the hybrid control unit 55 which is a host ECU and outputting the inverter drive signal to the inverter unit 30. To do.
The storage unit 53 is configured by a nonvolatile memory such as an EEPROM, and stores a deterioration state of the SW elements 31 to 36 and the like.

  The hybrid control unit 55 is configured mainly by a microcomputer including a CPU, a ROM, a RAM, and the like, and executes various controls by executing various control programs stored in the ROM. The hybrid control unit 55 receives signals from an accelerator sensor, a shift switch, a brake switch, a vehicle speed sensor, and the like (not shown), and controls the entire vehicle 90 based on the acquired signals.

In the present embodiment, the MG control unit 51 performs an initial check when the system is activated. In the initial check, the deterioration state of the SW elements 31 to 36 is determined based on the element temperature T.
Deterioration state determination processing based on the element temperature T will be described based on the flowchart shown in FIG. The deterioration state determination process is a process executed by the calculation unit 52 when a start switch (not shown) such as an ignition power supply is turned on and the vehicle control system 1 is ready on.

  In the first step S101 (hereinafter, “step” is omitted and simply indicated by the symbol “S”), it is determined whether or not the circuit unit 20 is activated. If it is determined that the circuit unit 20 is not activated (S101: NO), this determination process is repeated. When it is determined that the circuit unit 20 is activated (S101: YES), the process proceeds to S102.

  In S102, it is determined whether or not a predetermined interval has elapsed since the previous deterioration determination. In the present embodiment, when the travel distance from the previous deterioration determination is equal to or greater than the predetermined distance, it is determined that “the predetermined interval has passed since the previous deterioration determination”. When it is determined that the predetermined interval has not elapsed since the previous deterioration determination (S102: NO), the processing after S103 is not performed. When it is determined that the predetermined interval has elapsed since the previous deterioration determination (S102: YES), the process proceeds to S103.

  In S <b> 103, it is determined whether or not the battery 15 is in a state where predetermined energy can be input to the circuit unit 20. In the present embodiment, when the SOC of the battery 15 is equal to or greater than the determination threshold value Sth, it is determined that the predetermined energy can be input to the circuit unit 20. The determination threshold value Sth is set to a value that is larger than the lower limit value of the SOC control range and is sufficient to use power for determining the deterioration state. When it is determined that the battery 15 is not in a state where predetermined energy can be input to the circuit unit 20 (S103: NO), that is, when the SOC is less than the determination threshold value Sth, the processing after S104 is not performed. When it is determined that the battery 15 is in a state where predetermined energy can be input to the circuit unit 20 (S103: YES), that is, when the SOC is equal to or greater than the determination threshold value Sth, the process proceeds to S104.

In S104, the pre-energization element temperature Tb, which is the element temperature T before the inverter unit 30 is energized, is acquired.
In S105, energization of the inverter unit 30 is started with a predetermined voltage and a predetermined current. At this time, the first clutch 16 and the second clutch 17 are disconnected so that the driving force is not transmitted.

In S106, it is determined whether or not a predetermined energization period Pe (for example, 200 msec) has elapsed since the start of energization. When it is determined that the energization period Pe has not elapsed (S106: NO), this determination process is repeated. When it is determined that the energization period Pe has elapsed (S106: YES), the process proceeds to S107.
In S107, energization to the inverter unit 30 is terminated. In the present embodiment, energizing the inverter unit 30 with a predetermined voltage and a predetermined current over a predetermined energization period Pe corresponds to “inputting predetermined energy to the circuit unit”.

In S108, a post-energization element temperature Ta which is the element temperature T after energization is acquired. In the present embodiment, in consideration of the delay of the change in the element temperature T, the element temperature T is monitored for a predetermined period after the end of energization, and the peak value is set as the element temperature Ta after energization.
In S109, a temperature rise value ΔT is calculated. The temperature rise value ΔT is calculated by the equation (1).
ΔT = Ta−Tb (1)

In S110, the deterioration state is determined based on the temperature rise value ΔT.
In S111, the deterioration state determined in S110 is stored in the storage unit 53. At this time, the travel distance information related to the determination in S102 is also stored in the storage unit 53, and the deterioration state determination process is terminated.

Here, determination of the deterioration state will be described with reference to FIGS.
FIG. 5 shows changes in the temperature rise value ΔT at each of degradation levels L1 to L3 described later. In the present embodiment, the initial state in which the SW elements 31 to 36 are least thermally degraded is the degradation level L1, then the degradation level L2, and the most thermally degraded state is the degradation level L3. Here, as the thermal degradation of the SW elements 31 to 36 progresses, the “degradation level is large”, and when the thermal degradation does not proceed, the “degradation level is small”.

As shown in FIG. 5, when the inverter unit 30 is energized with a predetermined voltage and a predetermined current, the increasing speed of the element temperature T varies depending on the deterioration state of the SW elements 31 to 36. That is, since the thermal resistance increases due to the progress of thermal degradation of the SW elements 31 to 36, the rate of increase in the element temperature T increases as the thermal degradation progresses.
Therefore, in this embodiment, the inverter unit 30 is energized with a predetermined voltage and a predetermined current, and the deterioration state is determined based on the temperature increase value ΔT after the energization period Pe has elapsed.

  Specifically, as shown in FIG. 6A, after the start switch is turned on and the vehicle control system 1 is ready, energization of the inverter unit 30 is started at a predetermined voltage and a predetermined current (time). x10). At this time, as shown in FIG. 6B, the shift range is the P range or the N range. In the present embodiment, when the motor generator 12 is driven by the engine 11 or when the driving wheel 95 is driven by the driving force of the motor generator 12, the motor generator 12 is affected by the temperature change due to the driving of the motor generator 12. The clutch 16 and the second clutch 17 are disconnected.

  As shown in FIG. 6C, when the inverter unit 30 is energized at a predetermined voltage and a predetermined current and the torque of the motor generator 12 (hereinafter referred to as “MG torque”) increases, the energization period starts from the energization start. The MG torque after Pe has elapsed is a predetermined torque Qa. When energization is terminated at time x11 after the energization period Pe has elapsed from time x10, the MG torque becomes zero.

As shown in FIG. 6D, the element temperature T rises as the MG torque increases due to energization. When energization ends at time x11, the element temperature T reaches a peak at time x12 slightly delayed from time x11, and then decreases. In the present embodiment, the element temperature before starting energization at time x10 is the pre-energization element temperature Tb1, the element temperature at time x12 is the post-energization element temperature Ta1, and the temperature rise value ΔT1 is calculated. Here, for the sake of explanation, it is assumed that the pre-energization element temperature Tb1 is the same as the pre-energization element temperatures Tb2 and Tb3 described later.
As shown in FIGS. 6D and 6E, the temperature rise value ΔT1 is equal to or lower than the first determination threshold value TH1 (for example, 70 [° C.]), so the deterioration state is set to the deterioration level L1.

Further, after the deterioration determination process based on the element temperature Ta1 after energization at time x12, when the start switch is turned on after a predetermined interval has elapsed, the period from time x20 to time x21 after the energization period Pe is the predetermined voltage and current. The inverter unit 30 is energized. When energization ends at time x21, the element temperature T reaches a peak at time x22 slightly delayed from time x21, and then decreases. In the present embodiment, the element temperature before starting energization at time x20 is the pre-energization element temperature Tb2, the element temperature at time x22 is the post-energization element temperature Ta2, and the temperature rise value ΔT2 is calculated.
As shown in FIGS. 6D and 6E, the temperature increase value ΔT2 is larger than the first determination threshold value TH1 and equal to or less than the second determination threshold value TH2 (for example, 90 [° C.]). Let L2.

Furthermore, after the deterioration determination process based on the post-energization element temperature Ta2 at time x22, when the start switch is turned on after a lapse of a predetermined interval, the predetermined voltage and the predetermined current are maintained for a period from time x30 to time x31 after the energization period Pe. Then, the inverter unit 30 is energized. When energization ends at time x31, the element temperature T reaches a peak at time x32 slightly delayed from time x31, and then decreases. In this embodiment, the element temperature before starting energization at time x30 is the pre-energization element temperature Tb3, the element temperature at time x32 is the post-energization element temperature Ta3, and the temperature rise value ΔT3 is calculated.
As shown in FIGS. 6D and 6E, the temperature rise value ΔT3 is larger than the second determination threshold value TH2, so the deterioration state is set to the deterioration level L3.

In the present embodiment, torque limit processing is performed using the torque limit map shown in FIG.
The torque limit coefficient is set based on the element temperature T using conversion lines F1, F2, and F3 corresponding to the deterioration levels L1, L2, and L3. In the present embodiment, the conversion line F1 when the deterioration level is L1, the conversion line F2 when the deterioration level L2, and the conversion line F3 when the deterioration level L3.

In the present embodiment, the restriction start temperature for starting torque restriction at the deterioration level L1 is Ts1, the restriction start temperature for starting torque restriction at the deterioration level L2 is Ts2, and the torque restriction is started at the deterioration level L3. The restriction start temperature is Ts3.
Further, when the deterioration level is L1, the element temperature T is equal to or higher than the output stop temperature Te1, when the deterioration level is L2, the element temperature T is equal to or higher than the output stop temperature Te2, and when the deterioration level is L3, the element temperature T is equal to or higher than the output stop temperature Te3. The coefficient is set to zero and the output from the motor generator 12 is stopped.

In the present embodiment, the limit start temperature Ts for starting the torque limit by setting the torque limit coefficient to less than 1 is set lower as the deterioration level is larger. That is, Ts3 <Ts2 <Ts1. Similarly, the output stop temperature Te is Te3 <Te2 <Te1.
Limit start temperature Ts1, Ts2, Ts3 and output stop temperature Te1, Te2, T3 can be set suitably.

Further, the torque limit inclination is set so as to increase as the deterioration level increases. That is, A1 <A2 <A3, where A1 is the torque limit slope at the degradation level L1, A2 is the torque limit slope at the degradation level L2, and A3 is the torque limit slope at the degradation level L3. The torque limit slope in the present embodiment is the absolute value of the slope of the function of the element temperature T and the torque limit coefficient between the limit start temperature and the output stop temperature.
In this embodiment, the deterioration state determination process is performed by the initial check at the time of starting the system. In the normal mode after the initial check is completed, the torque limit is determined using a specific torque limit map corresponding to the stored deterioration state. Process.

Next, the torque limiting process according to the deterioration state will be described based on the flowchart shown in FIG. The torque limiting process is executed by the MG control unit 51 when the vehicle control system 1 is ready.
In S201, it is determined whether or not the initial check is finished. If it is determined that the initial check has not ended (S201: NO), this determination process is repeated. When it is determined that the initial check has been completed (S201: YES), the process proceeds to S202.

In S202, the deterioration state stored in the storage unit 53 is read.
In S203, with reference to the torque limit map shown in FIG. 7, the limit start temperature Ts corresponding to the deterioration state is determined.
In S204, it is determined whether or not driving of the motor generator 12 is started. When it is determined that driving of the motor generator 12 is not started (S204: NO), this determination process is repeated. When it is determined that driving of the motor generator 12 has been started (S204: YES), the process proceeds to S205.

In S205, the element temperature T is acquired.
In S206, it is determined whether or not the element temperature T acquired in S205 is higher than the restriction start temperature Ts. When it is determined that the element temperature T is higher than the limit start temperature Ts (S206: YES), the process proceeds to S207. When it is determined that the element temperature T is equal to or lower than the limit start temperature Ts (S206: NO), the process proceeds to S208.
In S207, a torque limit coefficient corresponding to the element temperature T and the deterioration state is acquired with reference to the torque limit map shown in FIG.
In S208, when the torque limit coefficient is set to 1 and the element temperature T is equal to or lower than the limit start temperature Ts, torque limit is not performed.

In S209, which is shifted from S207 or S208, the post-limit torque trq_r is calculated. The post-restriction torque trq_r is a value obtained by multiplying the torque command value trq ^* acquired from the hybrid control unit 55 by the restriction coefficient determined in S207 or S208, and controls driving of the motor generator 12 based on the post-restriction torque trq_r. To do. In addition, you may comprise so that the process which concerns on S209 may be performed by the process different from the process which determines the restriction | limiting start temperature Ts and a torque limitation coefficient.
In S210, it is determined whether or not the start switch has been turned off. When it is determined that the start switch is not turned off (S210: NO), the process returns to S205. If it is determined that the start switch has been turned off (S210: YES), this process ends.

Here, the torque limiting process will be described based on the time church shown in FIG. In FIG. 9, the deterioration level L3 is indicated by a solid line, the deterioration level L1 is indicated by a broken line, and a reference example is indicated by a dashed line. In FIG. 9, the influence of delay elements due to filter processing or the like is omitted.
As shown in FIGS. 9A, 9B, and 9C, when the vehicle control system 1 is ready and the command torque trq ^* after the shift range is switched from the P range to the D range is a constant value Qs. Will be described as an example. Further, until time x1 when the element temperature T reaches the restriction start temperature Ts3 at the deterioration level L3, the torque restriction is not performed regardless of the deterioration state and the torque restriction coefficient is 1. Therefore, the post-restriction torque trq_r and the command torque trq ^* is equal.

When the deterioration level is L3, the thermal resistance of the SW elements 31 to 36 is large, and the element temperature T is likely to rise. Therefore, torque limitation is performed from the restriction start temperature Ts3 lower than the restriction start temperatures Ts1 and Ts2 at the deterioration levels L1 and L2. Do.
In the example of FIG. 9, as shown by the solid line, torque limitation is started at time x1 when the element temperature T becomes higher than the limitation start temperature Ts3. Further, during the period from time x2 to time x4 when the element temperature T is higher than the output stop temperature Te3, the torque limit coefficient is set to zero and the post-limit torque trq_r is set to zero. At time x5 when the element temperature T decreases due to the torque limit and becomes equal to or lower than the limit start temperature Ts3, the torque limit coefficient is set to 1, and the torque limit ends. The post-limit torque trq_r during the period from time x1 to time x5 when the torque is limited is a value obtained by multiplying the command torque trq ^* by a torque limit coefficient corresponding to the element temperature T. Although the post-limit torque trq_r changes according to the element temperature T, it is described as linearly changing in FIG. 9 for simplification. Further, in order to avoid a sudden change in the torque, a filter process or the like may be appropriately performed so that the change in the post-restriction torque trq_r becomes slower than the change in the torque limit coefficient.

As indicated by the broken line, when the deterioration level is L1, the thermal resistance of the SW elements 31 to 36 is small and the element temperature T is difficult to increase. Therefore, torque limitation is performed until time x6 when the element temperature T becomes higher than the limit start temperature Ts1. Therefore, the output of the motor generator 12 does not decrease. When the torque limit is started at time x6, the element temperature T changes from increasing to decreasing at time x8, and at time x9 when the element temperature T is equal to or lower than the limit start temperature Ts1, the torque limit coefficient is set to 1 and the torque limit is set. finish. The post-restriction torque trq_r in the period from time x6 to time x9 when the torque is restricted is a value obtained by multiplying the command torque trq ^* by a torque restriction coefficient corresponding to the element temperature T.

In the reference example, it is assumed that torque limitation is performed when the element temperature T becomes higher than a predetermined temperature without considering the deterioration state. FIG. 9 shows an example in which the torque is limited when the element temperature T exceeds the limit start temperature Ts1.
As shown by the one-dot chain line in FIG. 9, when the deterioration level is large, if the torque limit is not performed until time x3 when the element temperature T reaches the limit start temperature Ts1, compared with the case where the deterioration level indicated by the broken line is small, The peak value Tp of the element temperature T at time x7 increases. Therefore, there is a possibility that the SW elements 31 to 36 are thermally deteriorated or the SW elements 31 to 36 are damaged depending on the peak value Tp.
On the other hand, although not shown, assuming that the deterioration start state is not taken into consideration and the restriction start temperature is Ts3, if the deterioration level is small, an extra torque restriction is applied.

  In the present embodiment, the limit start temperature and the torque limit slope are set according to the deterioration state. As a result, it is possible to limit the torque appropriately according to the deterioration state. Therefore, when the deterioration level is small, the torque can be output from the motor generator 12 without applying an excessive torque limit, and the drivability is improved. . Further, when the deterioration level is large, torque limitation can be started from a low temperature and the torque can be limited quickly. Therefore, further thermal deterioration of the SW elements 31 to 36 can be suppressed, and thermal destruction can be avoided.

As described above in detail, the MG control unit 51 performs the following processing.
The MG control unit 51 acquires a pre-energization element temperature Tb that is an element temperature before energizing the circuit unit 20 having the SW elements 31 to 36 related to switching of energization of the motor generator 12 (S104 in FIG. 4).
The MG control unit 51 obtains a post-energization element temperature Ta that is an element temperature after supplying predetermined energy by energizing the circuit unit 20 in a state where the driving force of the motor generator 12 is not transmitted to the drive wheels 95. (S108).

The MG control unit 51 determines the deterioration state of the circuit unit 20 based on the temperature increase value ΔT that is the difference between the post-energization element temperature Ta and the pre-energization element temperature Tb (S110), and stores the determined deterioration state in the storage unit 53 (S111).
The MG control unit 51 limits the torque output from the motor generator 12 based on the deterioration state and the element temperature T (S209 in FIG. 8).
The limit start temperature Ts, which is the element temperature T at which the torque limit is started, and the torque limit slope according to the element temperature T are variable according to the deterioration state.

  In the present embodiment, the deterioration is based on the temperature increase value ΔT of the SW elements 31 to 36 when a predetermined energy is input by energizing the circuit unit 20 in a state where the driving force of the motor generator 12 is not transmitted to the driving wheels 95. The state is being judged. Thereby, the deterioration state of SW elements 31 to 36 can be appropriately determined without being affected by the temperature change of motor generator 12 accompanying the transmission of the driving force.

  In addition, since the restriction start temperature for starting torque restriction and the torque restriction inclination are variable according to the deterioration state, the motor generator 12 can be appropriately controlled according to the deterioration state of the circuit unit 20. Thereby, it is possible to avoid excessive torque limitation in a state where the deterioration of the circuit unit 20 is small. Further, since the torque can be quickly limited in a state in which the circuit unit 20 is largely deteriorated, further thermal deterioration of the circuit unit 20 can be suppressed and damage to the circuit unit 20 can be prevented.

  The MG control unit 51 determines the deterioration state after a predetermined interval has elapsed since the previous deterioration determination (S102: YES). For example, when performing the deterioration determination by the initial check at the time of starting the system, it is not always necessary to perform the deterioration determination every time. If the predetermined interval has not elapsed, the deterioration determination process is omitted. Thereby, the time required for the initial check can be shortened.

  When it is determined that the battery 15 that supplies electric power to the motor generator 12 is in a state where predetermined energy can be input to the circuit unit 20 (S103: YES), the MG control unit 51 determines the deterioration state. That is, for example, when the remaining charge of the battery 15 is small, the deterioration state is not determined. As a result, it is possible to prevent the battery 15 from being over-discharged or fuel consumption deteriorated due to the determination of the deterioration state.

  In the present embodiment, the temperature of the circuit unit 20 is an element temperature T that is the temperature of the SW elements 31 to 36. Thereby, based on the temperature of SW element 31-36, a deterioration level can be determined appropriately and the thermal damage of SW element 31-36 can be prevented.

In the present embodiment, the MG control unit 51 constitutes “pre-energization temperature acquisition means”, “post-energization temperature acquisition means”, “degradation state determination means”, “storage means”, and “torque restriction means”. Also, S104 in FIG. 4 corresponds to the process as the function of “pre-energization temperature acquisition means”, S108 corresponds to the process as the function of “post-energization temperature acquisition means”, and S110 corresponds to “degradation state determination means”. S111 corresponds to the processing as the function of the “storage means”, and S209 in FIG. 8 corresponds to the processing as the function of the “torque limiting means”.
The element temperature T corresponds to the “temperature of the circuit portion”, the pre-energization element temperature Tb corresponds to the “pre-energization temperature”, and the post-energization element temperature Ta corresponds to the “post-energization temperature”.

(Other embodiments)
(A) Circuit part temperature In the said embodiment, the temperature of SW element which comprises an inverter is made into the temperature of a circuit part. In another embodiment, the temperature of the freewheeling diode may be used as the temperature of the circuit unit instead of the temperature of the SW element. Further, the temperature of the electronic component such as the reactor, the SW element, or the capacitor constituting the boost converter may be set as the temperature of the circuit unit. For example, when the temperature of the capacitor is set to the temperature of the circuit portion, the deterioration state of the capacitor is monitored as the deterioration state of the circuit portion, so that thermal deterioration of the capacitor can be suppressed and thermal destruction can be prevented.
Further, the wiring temperature of a bus bar or the like used for connecting electronic components may be used as the temperature of the circuit unit. In another embodiment, the cooling water temperature of the power card may be the temperature of the circuit unit.

(A) Deterioration state determination means In the above embodiment, the deterioration level is set in three stages. In another embodiment, the deterioration level is not limited to three stages, but may be two stages, may be four stages or more, or may be continuously changed. When the deterioration level is set continuously, the torque of the motor generator may be limited by, for example, a function using a continuously changing deterioration level value.

  In the above embodiment, the deterioration state is determined based on the temperature rise value itself. In another embodiment, the deterioration state may be determined based on the temperature rise value and the set value. For example, the temperature rise value when predetermined energy is input to the circuit portion in the average deterioration state may be set as a set value, and the deterioration state may be determined based on the difference between the set value and the actual temperature increase value. Further, for example, a predetermined range including a set value is set as a normal deterioration range, and when the temperature rise value is smaller than the normal deterioration range, the deterioration level is small, and when the temperature rise value is larger than the normal deterioration range, the deterioration level is large. In addition, the deterioration state may be determined.

In another embodiment, for example, a notification unit that notifies the user of the deterioration state may be provided, such as displaying the deterioration state on an instrumental panel. By notifying the user of the deterioration state, it is possible to prompt the user not to perform excessive driving or to promptly perform maintenance.
Further, maintenance information such as a power card replacement time may be estimated based on the deterioration state. The estimated maintenance information may be notified to the user.

In the above embodiment, when the travel distance from the previous deterioration determination is equal to or greater than the predetermined distance, it is determined that the predetermined interval from the previous deterioration determination has elapsed.
In the valley embodiment, for example, when time information is acquired from a navigation device (not shown) and the elapsed time from the previous deterioration determination is equal to or longer than a predetermined time, it is determined that “a predetermined interval has passed since the previous deterioration determination”. May be. When determining the elapse of the predetermined interval based on the time information, in S111 in FIG. 4, the time information related to the time when the deterioration determination is performed is stored in the storage unit together with the deterioration state.

  Further, one trip is defined as the time from when the start switch is turned on until it is turned off, and the number of trips is counted based on the start switch being turned off / on. Then, instead of the travel distance, when the number of trips from the previous deterioration determination becomes a predetermined number or more, it may be determined that “a predetermined interval has passed since the previous deterioration determination”. When determining the elapse of the predetermined interval based on the number of trips, in S111, a counter related to the count of the number of trips may be reset.

  In another embodiment, the process of S102 in FIG. 4 may be omitted, and the deterioration state determination process may be performed at each initial check. In this case, the determined deterioration state may be stored in a RAM or the like in the calculation unit instead of the storage unit configured by an EEPROM or the like, and the storage unit may be omitted.

In another embodiment, the deterioration state determination process may be executed not only at the initial check but at any time as long as the driving force of the rotating electrical machine is not transmitted to the drive target. For example, the deterioration state determination process may be performed during inertial running with the first clutch and the second clutch disengaged. In addition, for example, forcible ready-on may be performed in the maintenance mode, and the deterioration state determination process may be performed.
In another embodiment, the process of S103 in FIG. 4 may be omitted, and the deterioration state may be determined regardless of the state of charge of the power source.

(C) Torque limiting means In the above embodiment, the torque is limited by multiplying the torque command value by the torque limiting coefficient. In other embodiments, for example, a voltage command value or a current command value may be multiplied by a limiting coefficient. Moreover, you may comprise so that a torque may be restrict | limited directly irrespective of a torque limitation coefficient.
In the above embodiment, the limit start temperature and the torque limit slope are variable according to the deterioration state. In another embodiment, the limit start temperature or the torque limit slope may be variable according to the deterioration state.

  In the above embodiment, the temperature of the circuit unit and the torque limit coefficient between the limit start temperature and the output stop temperature have a linear relationship. In another embodiment, the interval between the restriction start temperature and the output stop temperature may be divided into a plurality of sections, and the slope may be changed for each section. The relationship between the temperature of the circuit unit and the torque limiting coefficient is not limited to a linear relationship such as a quadratic or higher function.

(D) Circuit Unit In the above embodiment, the SW element is composed of an IGBT. In other embodiments, the SW element may be composed of a semiconductor element other than the IGBT. In the said embodiment, SW element is comprised with the power card and is a double-sided heat dissipation structure. In another embodiment, the heat dissipation structure of the SW element may be single-sided heat dissipation. Moreover, you may comprise an inverter part other than a power card.
In the above embodiment, the circuit unit has a boost converter. In other embodiments, the boost converter may be omitted.

(E) Control device In the above embodiment, each means is constituted by an MG control unit. In another embodiment, a part or all of each unit may be configured by a hybrid control unit. Further, the MG control unit and the hybrid control unit may be configured as one control unit.
In the above embodiment, the control device is applied to a hybrid vehicle. Other embodiments are applicable not only to hybrid vehicles but also to all vehicles using main motors such as electric vehicles and fuel cell vehicles. Further, the control device may be applied to other devices, and the drive target is not limited to the drive wheel.
As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.

DESCRIPTION OF SYMBOLS 1 ... Vehicle control system 12 ... Motor generator (rotary electric machine)
15 ... Battery (power supply)
DESCRIPTION OF SYMBOLS 20 ... Circuit part 31-36 ... SW element 51 ... MG control part (control apparatus)
52 ... Calculation unit 53 ... Storage unit 95 ... Driving wheel (drive target)

Claims (5)

Pre-energization temperature acquisition means (S104) for acquiring a pre-energization temperature that is the temperature of the circuit unit before energizing the circuit unit (20) having the switching elements (31 to 36) related to switching of energization of the rotating electrical machine (12). )When,
Wherein in a state where the driving force is not reached transfer between said rotating electric machine and said another apparatus by turning off the clutch (16, 17) provided between the rotary electric machine and the other device (11,95) A post-energization temperature acquisition means (S108) for acquiring a post-energization temperature, which is a temperature of the circuit unit after supplying predetermined energy by energizing the circuit unit;
Degradation state determination means (S110) for determining a deterioration state of the circuit unit based on a temperature rise value that is a difference between the post-energization temperature and the pre-energization temperature;
Storage means (S111) for storing the determined deterioration state in the storage unit (53);
Torque limiting means (S209) for limiting the torque output from the rotating electrical machine based on the deterioration state and the temperature of the circuit unit;
With
At least one of a limit start temperature that is a temperature of the circuit unit that starts torque limit and a torque limit slope that depends on the temperature of the circuit unit is variable according to the deterioration state. (51).   The control device according to claim 1, wherein the deterioration state determination unit determines the deterioration state after a predetermined interval has elapsed since the previous deterioration determination.   The deterioration state determination means determines the deterioration state when it is determined that the power source (15) that supplies power to the rotating electrical machine is in a state where the predetermined energy can be input to the circuit unit. The control device according to claim 1 or 2.   The control device according to claim 1, wherein the temperature of the circuit unit is a temperature of the switching element. The circuit unit includes a capacitor (26),
The control device according to claim 1, wherein the temperature of the circuit unit is a temperature of the capacitor.

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