Patent ID: 12253421

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In view of the circumstances, as disclosed in JP 5786452 B, a known control device estimates the temperature of the cable or the ambient temperature of the cable and when determining that the estimated temperature exceeds a threshold temperature, limits the output of the rotating electrical machine in order to prevent the cable from being overheated.

At the time of estimating the temperature of the cable, if the initial temperature value of the cable is not properly set, the accuracy of estimating the temperature of the cable may be reduced. Particularly, there may be a reduction in the accuracy of estimating the temperature of the cable immediately after the rotating electrical machine is driven.

The following description will assume, for example, that in the situation where the cable is almost overheated, driving of the rotating electrical machine is stopped to cause the rotating electrical machine to stop and remain stationary, and then immediately after that, the rotating electrical machine is restarted. Regarding estimation of the temperature of the cable, suppose that the initial temperature value of the cable, for example, is set to a value equal to the ambient temperature of the cable. In this case, subsequently, under the situation where an electric current flows to the cable, the estimated temperature of the cable may be lower than the actual temperature of the cable. This leads to a concern that the actual temperature of the cable may exceed the upper tolerable limit thereof and the cable may be overheated.

Note that a target subject to the temperature estimation is not limited to the cable. In a system including a power storage device and a power converter electrically connected to the power storage device, as long as the target subject to the temperature estimation is a component included in the system and having a temperature increasing when electric power is transferred between the power converter and the power storage device by the operation of the power converter, the aforementioned problem may likewise occur.

The present disclosure has a primary object to provide a temperature estimation device capable of increasing the accuracy of estimating the temperature of an estimation target component.

According to the present disclosure, a temperature estimation device is applicable to a system including a power storage device and a power converter electrically connected to the power storage device and is used to estimate a temperature of an estimation target component included in the system and having a temperature increasing when electric power is transferred between the power converter and the power storage device by operation of the power converter. The temperature estimation device includes an initial value estimation unit that estimates an initial temperature value of the estimation target component at the start of the operation of the power converter, a variation estimation unit that estimates a temperature variation of the estimation target component based on a value of an electric current supplied from the power converter by the operation of the power converter, and a temperature estimation unit that calculates an estimated temperature of the estimation target component based on the initial temperature value and the temperature variation.

The initial value estimation unit estimates the initial temperature value based on time elapsed between the previous issuance of a temperature estimation stop instruction for the estimation target component and current issuance of a temperature estimation start instruction for the estimation target component.

According to the present disclosure, at the start of the operation of the power converter, the initial temperature value of the estimation target component is estimated. Subsequently, the temperature variation of the estimation target component is estimated based on the value of the electric current supplied from the power converter according to the operation of the power converter. Furthermore, the estimated temperature of the estimation target component is calculated based on the estimated initial temperature value and the estimated temperature variation.

The time elapsed between the previous issuance of the temperature estimation stop instruction for the estimation target component and the current issuance of the temperature estimation start instruction for the estimation target component has a significant impact on the accuracy of estimating the initial temperature value. In view of this point, the initial temperature value is estimated based on the elapsed time in the present disclosure. Therefore, the accuracy of estimating the temperature of the estimation target component can be increased.

First Embodiment

Hereinafter, the first embodiment of a temperature estimation device according to the present disclosure will be described with reference to the drawings. The temperature estimation device according to the present embodiment is included in a system to be installed in a hybrid vehicle, an electric vehicle, or the like.

As illustrated inFIG.1, a vehicle10includes a rotating electrical machine20, an inverter30serving as a power converter, and a storage battery40serving as a power storage device. The rotating electrical machine20is, for example, a star-connected, brushless synchronous machine. A rotor for the rotating electrical machine20is designed to be able to transmit motive power to driving wheels of vehicle10. Thus, the rotating electrical machine20serves as a power source for travel of the vehicle10.

The storage battery40is a secondary cell which can be charged and discharged and is specifically a lithium-ion battery or a nickel-metal hydride battery, for example. The storage battery40serves as a power supply source for the rotating electrical machine20when the rotating electrical machine20functions as an electric motor, and stores generated electric power when the rotating electrical machine20functions as an electric generator.

The inverter30includes: switches SW for the same number of pairs of upper and lower arms as the number of phases (three phases); and a capacitor31for smoothing. Each of the switches SW is, for example, a semiconductor switching element of the voltage control type and is specifically an N-channel metal-oxide-semiconductor field-effect transistor (MOSFET) or insulated-gate bipolar transistor (IGBT). In each phase, the connection point between the switches SW in the upper and lower arms is connected to a connector unit32of the inverter30.

The vehicle10includes alternating current cables33for the three phases. In each phase, the first end of the alternating current cable33is connected to the connector unit32of the inverter30, and the second end of the alternating current cable33is connected to a connector unit21of the rotating electrical machine20. In each phase, the connector unit21of the rotating electrical machine20is connected to a stator winding of the rotating electrical machine20.

The vehicle10includes a relay35that connects the storage battery40and the inverter30. When the relay35is turned ON, the relay35electrically connects the storage battery40and the inverter30to each other, and when the relay35is turned OFF, the relay35electrically disconnects the storage battery40and the inverter30from each other.

The vehicle10includes a charger50serving as the power converter. A charging connector unit51of the charger50is designed to be connectable, via a charging cable61, to power supply equipment60provided outside the vehicle10. The charger50converts alternating current power supplied from the power supply equipment60via the charging cable61and the charging connector unit51into direct current power, and supplies the direct current power to the storage battery40. Thus, the storage battery40is charged. Note that a relay is provided between the storage battery40and the charger50as well, but illustration of said relay is omitted inFIG.1.

The vehicle10includes a cooling device70that cools the inverter30. In the present embodiment, the cooling device70includes a cooling water passage in which a cooling fluid (cooling water) for cooling the inverter30flows, a pump configured to circulate the cooling water through said passage, and a fan configured to send air to the inverter30to cool the inverter30.

The rotating electrical machine20, the inverter30, the alternating current cable33, the relay35, the storage battery40, and the charger50are arranged in a motor compartment which is a predetermined device arrangement space provided in the vehicle10. The motor compartment is provided in front of the driver's seat in the vehicle10, for example.

The vehicle10includes a phase current sensor80and an ambient temperature sensor81. The phase current sensor80detects a phase current flowing through the alternating current cable33. In the present embodiment, a contactless phase current sensor including a current transformer, for example, is used as the phase current sensor80. The ambient temperature sensor81measures the temperature in the motor compartment as an ambient temperature Tmr. Particularly, in the present embodiment, the ambient temperature sensor81measures the temperature in an area around the alternating current cable33in the motor compartment as the ambient temperature Tmr. Detection values of the phase current sensor80and the ambient temperature sensor81and the operating state of the cooling device70are input to an electronic control device (ECU90) included in the vehicle10.

The ECU90, which is primarily composed of a microcomputer, operates the relay35, operates each of the switches SW in the inverter30in order to control the torque of the rotating electrical machine20to conform to a command torque, and operates the charger50in order to charge the storage battery40, for example. Note that in the present embodiment, the storage battery40is charged while the vehicle10is stationary. The ECU90can provide functions by way of software recorded in a tangible memory device, a computer and hardware that execute said software, or a combination thereof, for example.

The ECU90performs a temperature estimation process in which the temperature of a component in the in-vehicle system is estimated. In the present embodiment, the alternating current cable33is set to the target subject to the temperature estimation in said process. The ECU90performs the temperature estimation process during the period between when it is determined that a temperature estimation start instruction has been issued and when it is determined that a temperature estimation stop instruction has been issued, and suspends the temperature estimation process over the period between when it is determined that the temperature estimation stop instruction has been issued and when it is determined that the temperature estimation start instruction has been issued.

In the present embodiment, when the ECU90determines that a driving permission for the rotating electrical machine20has been issued, the ECU90determines that the temperature estimation start instruction has been issued. Furthermore, when the ECU90determines that a driving stop instruction for the rotating electrical machine20has been issued, the ECU90determines that the temperature estimation stop instruction has been issued. Therefore, an electric current does not flow to the alternating current cable33in the period between the issuance of the temperature estimation stop instruction and the issuance of the temperature estimation start instruction. Note that when the ECU90determines that the relay35has been switched ON, the ECU90may determine that the driving permission has been issued, and when the ECU90determines that the relay35has been switched OFF, the ECU90may determine that a driving stop instruction has been issued, for example.

FIG.2shows the temperature estimation process. This process is triggered by the determination that the temperature estimation start instruction for the alternating current cable33has been issued.

In Step S10, an initial value estimation process is performed in which an initial temperature value Tini of the alternating current cable33is estimated. This process will be described in detail later. Note that the process in Step S10corresponds to the initial value estimation unit.

After completion of the process in Step S10, the processes in Steps S11to S15are performed. The processes in Steps S11to S15are repeatedly performed in a predetermined control cycle.

In Step S11, a temperature variation ΔT of the alternating current cable33after the issuance of the temperature estimation start instruction is calculated based on the value of an electric current detected by the phase current sensor80and the ambient temperature Tmr measured by the ambient temperature sensor81. Specifically, the temperature variation ΔT is calculated based on the amount of heat generated at the alternating current cable33and the amount of heat released from the alternating current cable33. It is sufficient that the amount of generated heat be calculated based on the value of the electric current detected by the phase current sensor80and the amount of heat received from heat-generating components located around the alternating current cable33. Similarly, it is sufficient that the amount of released heat be calculated based on the temperature difference between the estimated temperature Test and the ambient temperature Tmr and the amount of heat released from the alternating current cable33by the cooling device70. The amount of heat released by the cooling device70includes the amount of heat released by air blown from the fan to the alternating current cable33and the amount of heat released from the alternating current cable33by the cooling water circulated by the pump. Note that the process in Step S11corresponds to the variation estimation unit.

In Step S12, the estimated temperature Test (n) of the alternating current cable33in the current control period is calculated by adding the temperature variation ΔT estimated in Step S11to the initial temperature value Tini estimated in Step S10. Note that the process in Step S12corresponds to the temperature estimation unit.

In Step S13, whether the estimated temperature Test calculated in Step S12is greater than or equal to a threshold temperature Tth is determined.

When the result of the determination made in Step S13is affirmative, the processing proceeds to Step S14, and the command torque is limited to the upper limit thereof. This suppresses an increase in the electric current (specifically, the amplitude of the alternating current) that flows to the alternating current cable33, preventing the alternating current cable33from being overheated.

When the process in Step S14is completed or when the result of the determination made in Step S13is negative, the processing proceeds to Step S15, and whether the temperature estimation stop instruction has been issued is determined. When it is determined that the temperature estimation stop instruction has not been issued, the processing proceeds to Step S11. On the other hand, when it is determined that the temperature estimation stop instruction has been issued, the temperature estimation process is stopped.

FIG.3shows the initial value estimation process performed in Step S10.

In Step S20, the time elapsed between the previous issuance of the temperature estimation stop instruction and the current issuance of the temperature estimation start instruction is calculated.

In Step S21, whether the elapsed time calculated in Step S20is less than predetermined time Lth is determined. It is sufficient that the predetermined time Lth be set to time required for the temperature of the alternating current cable33to reach the temperature in the motor compartment, for example. More specifically, for example, when the temperature in the motor compartment is maintained at a temperature equal to the upper limit of the possible range of the temperature in the motor compartment, it is sufficient that the predetermined time Lth be set to time required for the temperature of the alternating current cable33to reach the temperature in the motor compartment from the temperature equal to the upper limit of the possible range of the temperature of the alternating current cable33. The predetermined time Lth is, for example, a value determined in advance according to experiments, numerical calculation, and the like.

When the result of the determination made in Step S21is affirmative, the processing proceeds to Step S22, and the initial temperature value Tini is set to the estimated temperature Test calculated immediately before the previous issuance of the temperature estimation stop instruction.

On the other hand, when the result of the determination made in Step S21is negative, the processing proceeds to Step S23, and the initial temperature value Tini is set to a predetermined temperature Tα. In other words, the initial temperature value Tini is reset to the predetermined temperature Tα. In the present embodiment, in response to the lapse of the predetermined time Lth after the previous issuance of the temperature estimation stop instruction, the predetermined temperature Tα the is set to upper limit (for example, 85° C.) of the possible range of the temperature of the alternating current cable33. When the process in Step S22or S23is completed, the processing proceeds to Step S11.

With reference toFIGS.4and5, one example of the method for calculating the estimated temperature Test will be described.

First, the case where the elapsed time calculated is less than the predetermined time Lth will be described with reference toFIG.4. InFIG.4, Tr represents the actual temperature of the alternating current cable33.

At time t1, the temperature estimation stop instruction is issued, and thus the temperature estimation process is stopped. Subsequently, at time t2, the temperature estimation start instruction is issued, and thus the temperature estimation process is resumed. At this time, the elapsed time expressed as time t1to t2is less than the predetermined time Lth, and thus the estimated temperature Test at time t1is used as the initial temperature value Tini.

Next, the case where the elapsed time calculated is greater than or equal to the predetermined time Lth will be described with reference toFIG.5.

At time t1, the temperature estimation stop instruction is issued, and thus the temperature estimation process is stopped. Subsequently, at time t3, the temperature estimation start instruction is issued, and thus the temperature estimation process is resumed. The elapsed time expressed as time t1to t3is greater than or equal to the predetermined time Lth, and thus the predetermined temperature Tα is used as the initial temperature value Tini. Although the estimated temperature Test changes by resetting at time t2inFIG.5for convenience of description, the estimation process is stopped in the period between time t1and time t3in actuality.

According to the present embodiment described above in detail, the following advantageous effects can be obtained.

In the present embodiment, the initial temperature value Tini of the alternating current cable33is estimated at the start of the operation of the inverter30. Subsequently, the temperature variation ΔT of the alternating current cable33is estimated based on the electric current detection value, etc., of the phase current sensor80during the operation of the inverter30. Thereafter, the temperature Test of the alternating current cable33is estimated based on the estimated initial temperature value Tini and the estimated temperature variation ΔT.

When the time elapsed between the previous issuance of the temperature estimation stop instruction and the current issuance of the temperature estimation start instruction is determined as being less than the predetermined time Lth, the initial temperature value Tini is set to the estimated temperature Test calculated immediately before the previous issuance of the temperature estimation stop instruction. On the other hand, when the elapsed time is determined as being greater than or equal to the predetermined time Lth, the predetermined temperature Tα is set to the initial temperature value Tini. In this manner, the initial temperature value Tini is estimated according to the elapsed time, and thus the accuracy of estimating the temperature of the alternating current cable33can be increased. As a result, for example, when the vehicle10remains stationary for a long period of time, the estimated temperature Test of the alternating current cable33can be prevented from becoming too high as compared to the actual temperature of the alternating current cable33, and when the vehicle10remains stationary for a short period of time, the estimated temperature Test of the alternating current cable33can be prevented from becoming too low as compared to the actual temperature of the alternating current cable33.

In response to the lapse of the predetermined time Lth after the previous issuance of the temperature estimation stop instruction, the predetermined temperature Tα is set to the upper limit of the possible range of the temperature of the alternating current cable33. Thus, the actual temperature of the alternating current cable33can reliably remain less than or equal to the estimated temperature Test, meaning that the alternating current cable33has proper overheat protection.

Second Embodiment

With reference to the drawings, the second embodiment will be described below, focusing on differences from the first embodiment. In the present embodiment, processing details of the initial value estimation process are different.

FIG.6shows an initial value estimation process according to the present embodiment. InFIG.6, processes that are the same as the processes illustrated inFIG.3described above are assigned the same reference signs for the sake of convenience.

After completion of Step S20, the processing proceeds to Step S24, and determines whether the elapsed time calculated is less than first predetermined time Lth1. When the result of the determination made in Step S24is affirmative, the processing proceeds to Step S22.

On the other hand, when the result of the determination made in Step S24is negative, the processing proceeds to Step S25, and whether the elapsed time calculated is greater than or equal to the first predetermined time Lth1and is less than second predetermined time Lth2(>Lth1) is determined. The predetermined time Lth described in the first embodiment is set to be equal to the second predetermined time Lth2, for example. When the elapsed time is determined as exceeding the second predetermined time Lth2in Step S25, the processing proceeds to Step S23.

On the other hand, when the result of the determination made in Step S25is affirmative, the processing proceeds to Step S26, and a value monotonically decreasing, in association with the elapsed time, from the estimated temperature Test calculated immediately before the previous issuance of the temperature estimation stop instruction, is estimated as the initial temperature value Tini. Hereinafter, with reference toFIG.7, the method for estimating the initial temperature value Tini in Step S26will be described.

InFIG.7, ta represents the point in time of the previous issuance of the temperature estimation stop instruction, tb represents the point in time of the current issuance of the temperature estimation start instruction, and Tend represents a stop timing temperature which is the estimated temperature Test immediately before the previous issuance of the temperature estimation stop instruction. Therefore, “tb-ta” is the elapsed time calculated in Step S20. In this case, the initial temperature value Tini is estimated using the following Equation 1, the elapsed time calculated in Step S20, the ambient temperature Tmr, and the stop timing temperature Tend.

[Math.⁢1]⁢Tini=Tm⁢r+(Tend-Tm⁢r)×e{-tb-taτ}Equation⁢⁢1

The above Equation 1 is an estimated equation in which the stop timing temperature Tend asymptotically approaches the ambient temperature Tmr according to the elapsed time. A time constant τ on the right hand side of the above Equation 1 is, for example, a value adapted according to experiments, numerical calculation, and the like, and is set to one to two hours. It is sufficient that the time constant τ be set based on the time required for the temperature of the alternating current cable33to reach the temperature in the motor compartment, for example. More specifically, for example, when the temperature in the motor compartment is maintained at a temperature equal to the upper limit of the possible range of the temperature in the motor compartment, it is sufficient that the time constant τ be set based on the time required for the temperature of the alternating current cable33to reach the temperature in the motor compartment from the temperature equal to the upper limit of the possible range of the temperature of the alternating current cable33.

The case where the elapsed time calculated is greater than or equal to the first predetermined time Lth1and is less than the second predetermined time Lth2will be described with reference toFIG.8.

At time t1, the temperature estimation stop instruction is issued, and thus the temperature estimation process is stopped. Subsequently, at time t2, the temperature estimation start instruction is issued, and thus the temperature estimation process is started. At this time, the initial temperature value Tini at time t2depends on the elapsed time expressed as time t1to t2, as explained earlier with reference toFIG.7. Although the estimated temperature Test changes between time t1and time t2inFIG.8for convenience of description, the estimation process is stopped in the period between time t1and time t2in actuality.

According to the present embodiment described thus far, it is possible to increase the accuracy of estimating the temperature of the alternating current cable33when the elapsed time calculated is greater than or equal to the first predetermined time Lth1and is less than the second predetermined time Lth2.

Third Embodiment

With reference to the drawings, the third embodiment will be described below, focusing on differences from the first and second embodiments. In the present embodiment, processing details of the initial value estimation process are different.

FIG.9shows an initial value estimation process according to the present embodiment. In the present embodiment, when the result of the determination made in Step S21is negative, the processing proceeds to Step S26. InFIG.9, processes that are the same as the processes illustrated inFIGS.3and6described above are assigned the same reference signs for the sake of convenience.

According to the present embodiment described thus far, advantageous effects equivalent to the advantageous effects obtained according to the second embodiment can be obtained.

Fourth Embodiment

With reference to the drawings, the fourth embodiment will be described below, focusing on differences from the first embodiment. In the present embodiment, processing details of the initial value estimation process are different.

FIG.10shows an initial value estimation process according to the present embodiment. InFIG.10, processes that are the same as the processes illustrated inFIG.3described above are assigned the same reference signs for the sake of convenience.

When the result of the determination made in Step S21is negative, the processing proceeds to Step S27, and the initial temperature value Tini is estimated based on the ambient temperature Tmr measured by the ambient temperature sensor81. In the present embodiment, a predetermined offset amount ΔC is added to the ambient temperature Tmr; thus, the initial temperature value Tini is estimated to have a value that is less than or equal to the upper limit of the possible range of the temperature in the motor compartment and is greater than the ambient temperature Tmr.

The case where the elapsed time calculated is greater than or equal to the predetermined time Lth will be described with reference toFIG.11.

At time t1, the temperature estimation stop instruction is issued, and thus the temperature estimation process is stopped. Subsequently, at time t3, the temperature estimation start instruction is issued, and thus the temperature estimation process is started. At this time, the initial temperature value Tini at time t3is a value obtained by adding the predetermined offset amount ΔC to the ambient temperature Tmr. Although the estimated temperature Test changes at time t2inFIG.11for convenience of description, the estimation process is stopped in the period between time t1and time t3in actuality.

According to the present embodiment described thus far, advantageous effects similar to the advantageous effects obtained according to the first embodiment can be obtained.

Modification of Fourth Embodiment

When the vehicle10includes, as the ambient temperature sensor81, a water temperature sensor that measures the temperature of the cooling water included in the cooling device70, the temperature of the cooling water measured by the water temperature sensor may be used as the ambient temperature Tmr in Step S27. Furthermore, in this case, the target subject to the temperature estimation may be the capacitor31. In this case, for example, the initial temperature value of the capacitor31which is disposed closer to a position at which the cooling water flows than the alternating current cable33is may be estimated to have the average value (for example, 65° C.) of the upper limit (for example, 85° C.) of the possible range of the temperature in the motor compartment and the temperature of the cooling water (for example, 45° C.).

Fifth Embodiment

With reference to the drawings, the fifth embodiment will be described below, focusing on differences from the first embodiment. In the present embodiment, processing details of the initial value estimation process are different.

FIG.12shows an initial value estimation process according to the present embodiment. InFIG.12, processes that are the same as the processes illustrated inFIG.3described above are assigned the same reference signs for the sake of convenience.

When the process in Step S20is completed, the processing proceeds to Step S28, and the predetermined time Lth is set greater as the estimated temperature Test calculated immediately before the previous issuance of the temperature estimation stop instruction (the stop timing temperature Tend according to the second embodiment) increases. Specifically, for example, when the estimated temperature Test calculated immediately before the previous issuance of the temperature estimation stop instruction is greater than the predetermined temperature Tα, the predetermined time Lth is set greater as the estimated temperature Test increases.

In the process in Step S28, when the estimated temperature Test is low, the estimated temperature Test is reset early to the predetermined temperature Tα, and when the estimated temperature Test is high, the resetting of the estimated temperature Test is delayed. Thus, in the case where the temperature estimation start instruction is issued, the initial temperature value Tini can be kept from falling below the actual temperature of the alternating current cable33.

Sixth Embodiment

With reference to the drawings, the sixth embodiment will be described below, focusing on differences from the second embodiment. The present embodiment results from applying, to the second embodiment, the change in the predetermined time described in the fifth embodiment.

FIG.13shows an initial value estimation process according to the present embodiment. InFIG.13, processes that are the same as the processes illustrated inFIG.6described above are assigned the same reference signs for the sake of convenience.

When the process in Step S20is completed, the processing proceeds to Step S29, and the first predetermined time Lth1and the second predetermined time Lth2are set greater as the estimated temperature Test calculated immediately before the previous issuance of the temperature estimation stop instruction increases. Specifically, for example, when the estimated temperature Test calculated immediately before the previous issuance of the temperature estimation stop instruction is greater than the predetermined temperature Tα, the first predetermined time Lth1and the second predetermined time Lth2are set greater as the estimated temperature Test increases.

Other Embodiments

Note that the above embodiments may be modified and implemented as follows.The process in Step S23inFIG.6may be changed into the process in Step S27inFIG.10.In Step S11inFIG.2, the temperature variation ΔT in one control period may be calculated. In this case, in Step S12, it is sufficient that the estimated temperature Test (n) in the current control period be calculated by adding the temperature variation ΔT calculated in Step S11to the estimated temperature Test (n-1) calculated in the previous control period.The ambient temperature sensor81may measure the temperature in the area around the vehicle10as the ambient temperature Tmr, for example, as long as the temperature correlates with the temperature in the motor compartment. Furthermore, the ambient temperature Tmr to be used in the temperature estimation process is not limited to the detection value of the sensor and may be an estimated value obtained by estimation in a predetermined process.For example, in a rotating electrical machine of the integrated mechanical and electrical type resulting from integration of the inverter30and the rotating electrical machine20, there are cases where an electrical path connecting the inverter30and the rotating electrical machine20is a busbar instead of the alternating current cable33. In this case, it is sufficient that the target subject to the temperature estimation in the temperature estimation process be set to the busbar.The target subject to the temperature estimation is not limited to the alternating current cable33. For example, the target subject to the temperature estimation may be the capacitor31, the connector unit32of the inverter30, or the connector unit21of the rotating electrical machine20as long as this component is included in the system and is included in a path in which an electric current flows by the operation of the inverter30.

Furthermore, the target subject to the temperature estimation is not limited to the alternating current cable33and may be, for example, the phase current sensor80, the charging connector unit51of the charger50, or the like.In a system in which the temperature estimation stop instruction is issued in response to issuance of an instruction to stop the ECU90and the temperature estimation start instruction is issued in response to issuance of an instruction to start the ECU90, in response to the current issuance of the instruction to start the ECU90, the ECU90may estimate the initial temperature value Tini based on the time elapsed between the previous issuance of the instruction to stop the ECU90and the current issuance of the instruction to start the ECU90. This estimation method is applied, for example, when the ECU90is operating while the rotating electrical machine20remains stationary, specifically, for example, during charging of the storage battery40using the power supply equipment60. In this case, at the start of the operation of the charger50, the initial temperature value of the charging connector unit51of the charger50can be properly estimated, and moreover the accuracy of estimating the temperature of the charging connector unit51during charging can be increased. Note that when the target subject to the temperature estimation is the charging connector unit51, it is sufficient that the temperature variation ΔT be calculated based on a detection value of a power current sensor that detects an electric current flowing to the storage battery40or a charging electric current value transmitted from the power supply equipment60, for example.The number of targets subject to the temperature estimation is not limited to one and may be two or more.The controllers and the methods used by the controllers that are described in the present disclosure may be implemented using a dedicated computer provided by configuring memory and a processor programmed by a computer program so as to perform one or more specific functions. Alternatively, the controllers and the methods used by the controllers that are described in the present disclosure may be implemented using a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the controllers and the methods used by the controllers that are described in the present disclosure may be implemented using one or more dedicated computers including a combination of: memory and a processor programmed so as to perform one or more functions; and a processor configured with one or more hardware logic circuits. The computer program may be stored in a tangible non-transitory computer-readable recording medium as an instruction to be performed by a computer.

While the present disclosure has been described with reference to embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. The present disclosure is intended to cover various modification examples and modifications within the range of equivalency. In addition, various combinations and configurations, and further, other combinations and configurations including more, less, or only a single element, are also within the spirit and scope of the present disclosure.