JP2013165571A - Electric vehicle driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a power converter such as an inverter from being cooled excessively, during charging from an external power supply to a charger.SOLUTION: If a temperature reduction amount of an inverter 104 in a charge duration time exceeds a temperature deviation between a charge start time predicted temperature and a minimum reached temperature, the inverter 104 is deemed to be excessively cooled as a result of cooling by a cooler 112 in the charge duration time. Consequently, if the temperature reduction amount exceeds the temperature deviation, a controller 120 modifies a charge condition so that the temperature reduction amount is reduced. Thereby, excessive cooling of the inverter 104 is alleviated. As a result, stress applied to a joint part and solder of electronic components of the inverter 104 by a temperature difference can be reduced.

Description

  The present invention relates to cooling control of an electric vehicle such as an electric vehicle or a plug-in hybrid drive electric vehicle.

  An electric vehicle travels with the power of a charging device such as a secondary battery, and charges the charging device by supplying power from the outside. For this purpose, the charging device, the electric motor as the power source of the vehicle, the inverter that converts the electric power of the charging device into the driving power of the electric motor, the alternating current supplied from the external power source is converted into the direct current, And a charger that adjusts the charging device to a voltage that can be charged. A hybrid drive electric vehicle with a plug-in function has a similar configuration.

  Cited Document 1 proposes to calculate the required charging period for the charging device in such an electric vehicle and set the charging start time from the scheduled boarding time of the given vehicle and the required charging period.

Japanese Patent No. 3554057

  The electric vehicle charges the charging device through a charger using an external power source when the vehicle is stopped. At that time, since the charger generates heat, the charger is cooled using a cooler. On the other hand, during traveling, electric power is supplied from the charging device to the electric motor via the inverter. At that time, since the inverter generates heat, the inverter is cooled using the same cooler.

  When the same cooler cools the charger and the inverter at the same time, the following problem occurs.

  Since the charging from the external power source to the charger is performed in a stopped state, the inverter is not in operation. When charging the charger from the external power source, the cooler simultaneously cools the operating charger and the non-operating inverter. Usually, the temperature of vehicle-mounted devices such as a charger and an inverter follows with a change in the outside air temperature. For this reason, regarding the change in the temperature of the day, even when the outside air temperature becomes the lowest temperature, the temperature of the on-vehicle equipment remains higher than the outside air temperature. And since the outside air temperature starts to rise before the temperature of the on-vehicle equipment reaches the minimum temperature, the temperature of the on-vehicle equipment usually does not decrease to the minimum value of the outside air temperature.

  However, when a charger is charged from an external power supply, the cooler cools both the charger that is in operation and the inverter that is not in operation, so the temperature of the inverter drops to the same level as the outside air temperature. Resulting in. As a result, the temperature difference of the inverter between the operating time and the non-operating time increases. The increase in the temperature difference of the inverter between when it is in operation and when it is not in operation causes stress due to temperature changes to the joints and solder of the electronic components used in the inverter, causing distortion in the joints, or This may adversely affect the durability of the inverter, such as causing cracks. In an electric vehicle, charging from an external power source to a charger is often performed at night or early morning when the temperature drops. As a result, the inverter is unnecessarily cooled, and the temperature difference between the inverter during operation and during non-operation increases.

  An object of the present invention is to prevent excessive cooling of a power converter such as an inverter accompanying charging from an external power source to a charger.

  In order to achieve the above object, a drive device for an electric vehicle according to the present invention includes an electric motor for traveling, a charging device that supplies electric power to the electric motor via a power converter, and a charging device that uses an external power source. And a charger that cools the power converter and the charger at the same time. The driving device controls the charger to charge the charging device using an external power source based on the setting means for setting the charging start time and the charging duration of the charging device, and the set charging start time and the charging duration. A charger control means for performing the operation, a minimum temperature achieving means for predicting a minimum temperature reached by the power converter in a non-operating state of the cooler, and a charge for predicting the temperature of the power converter at the charging start time as the temperature at the start of charging. Starting temperature prediction means. The drive device further includes a temperature deviation calculating means for calculating a temperature deviation between the predicted temperature at the start of charging and the lowest attained temperature, a temperature drop amount predicting means for predicting a temperature drop amount of the power converter during the charging duration, and a temperature Comparing means for comparing the decrease amount with the temperature deviation, and charging condition correcting means for correcting the charging condition so that the temperature decrease amount becomes smaller when the temperature decrease amount exceeds the temperature deviation.

  If the temperature drop of the power converter while charging the charging device exceeds the temperature deviation between the estimated temperature at the start of charging and the minimum temperature, the power converter will be excessive as a result of cooling by the cooler during the charging duration. Considered to be cooled. In this case, the charging condition correcting means corrects the charging condition so that the amount of temperature decrease is small. This prevents excessive cooling of the power converter. As a result, the stress caused by the temperature difference on the joints and solder of the electronic components of the power converter is reduced.

It is a schematic block diagram of the drive device of the electric vehicle by embodiment of this invention. It is a diagram which shows the outside temperature and the temperature change of an inverter for one day. It is the diagram which shows the temperature change of the inverter accompanying the charge to a secondary battery, and its principal part enlarged view. It is a flowchart explaining the charge control routine which the controller by embodiment of this invention performs. It is the diagram explaining the influence which the change of the charge start timing which a controller performs performs on the temperature of an inverter, and the principal part enlarged view. It is the diagram explaining the influence which the output restriction of the cooler which a controller performs on the temperature of an inverter, and the principal part enlarged view.

  Referring to FIG. 1, an electric vehicle 1 travels by rotating a traveling electric motor 105 with electric power supplied from a secondary battery 103 serving as a power storage device. An inverter 104 is interposed between the secondary battery 103 and the electric motor 105 as a power converter for necessary power conversion and output control.

  Charging of the secondary battery 103 is performed by connecting the external power source 101 to the charging port 106 provided in the electric vehicle 1 while the electric vehicle 1 is stopped. A charger 102 mounted on the electric vehicle 1 is connected to the charging port 106. The alternating current supplied from the external power source 101 is converted into direct current by the charger 102 and further adjusted to a voltage suitable for charging the secondary battery 103, and then supplied to the secondary battery 103. Is charged. Charging of the secondary battery 103 by the external power source 101 is performed while the electric vehicle 1 is stopped.

  While the electric automobile 1 is running with the power of the electric motor 105, the inverter 104 generates heat. Further, the charger 102 generates heat during charging from the external power source 101 to the secondary battery 103.

  In order to cool these devices, the electric vehicle 1 is provided with a cooler 112 and a cooling passage 113. The cooling passage 113 is formed through each housing of the charger 102 and the inverter 104. The cooler 112 circulates the refrigerant in the cooling passage 113 and cools the refrigerant circulating in the cooling passage 113 using, for example, a radiator. The cooler 112 automatically enters an operating state as at least one of the charger 102 and the inverter 104 operates. That is, when the electric vehicle 1 is traveling or when the secondary battery 103 is charged from the external power source 101, the cooler 112 is always operated.

  FIG. 2 shows the outside air temperature and the temperature change of the inverter 104 when the electric vehicle 1 operates a plurality of times a day. As shown by a broken line 203 in the figure, the outside air temperature changes between the highest temperature in the daytime and the lowest temperature in the middle of the night or early morning. The figure shows how the electric vehicle 1 is operated multiple times during the day. Each time the electric vehicle 1 is operated, the temperature of the inverter 104 rapidly increases as indicated by a solid line 201 in the figure, and slowly approaches the outside temperature after the operation of the electric vehicle 1 is stopped. Further, the temperature of the inverter 104 when neither the operation of the electric motor 105 nor the charging of the secondary battery 103 is performed follows the outside air temperature with a certain delay as shown by a one-dot chain line 205 in the figure.

  The timing 204 in the figure indicates the timing at which the outside air temperature reaches the minimum temperature. The timing 202 in the figure indicates the timing at which the inverter 104 reaches the minimum temperature. Thus, the minimum temperature of the inverter 104 appears later than the minimum temperature of the outside air temperature, and the minimum temperature of the inverter 104 is higher than the minimum temperature of the outside temperature. This is because the outside air temperature starts to rise before the minimum temperature of the components of the inverter 104 reaches the minimum outside air temperature.

  Next, consider a case where the secondary battery 103 is charged from the external power source 101. This charging is performed while the electric vehicle 1 is stopped. When the electric vehicle 1 travels in the daytime, the secondary battery 103 is charged at, for example, midnight or early morning according to a predetermined charging schedule.

  Referring to FIG. 3, consider a case where secondary battery 103 is charged from external power source 101 from midnight to past 2:00. During charging of the secondary battery 103, the cooler 112 operates to cool the charger 102. The cooler 112 cools the charger 102 and the inverter 104 through the cooling passage 113. As a result, during charging of the secondary battery 103, the temperature of the inverter 104 decreases from the broken line 201 to the solid line 301 as shown in FIGS.

  In other words, as a result of the cooling of the inverter 104 by the cooling passage 113, the temperature of the inverter 104 improves the followability to the outside air temperature indicated by the broken line 203. As a result, the temperature of the components of the inverter 104 also reaches the minimum temperature at a timing 302 slightly delayed from the minimum temperature reaching timing of the outside air temperature shown in the timing 204 of FIG.

  Here, the temperature of the components of the inverter 104 when the secondary battery 103 is not charged is indicated by a broken line 201. As can be seen from this figure, by charging the secondary battery 103, the minimum temperature of the inverter 104 is significantly lower than when the secondary battery 103 is not charged. Will be equal. Also, the timing 302 at which the minimum temperature is reached is very close to the timing 204 at which the outside air temperature becomes the minimum temperature, as compared with the case where the secondary battery 103 is not charged.

  That is, by charging the secondary battery 103 from the external power source 101 while the inverter 104 is not operating, the inverter 104 is unnecessarily cooled. As a result, the temperature difference between when the inverter 104 is in operation and when it is not operating is widened, and stresses due to temperature changes are applied to the joints and solder of the electronic components used in the inverter 104. Cause cracks.

  The present invention prevents an increase in temperature difference between when the inverter 104 is in operation and when it is not in operation due to the charging of the secondary battery 103 through the control of the charger 102.

  For this control, the drive device for the electric vehicle 1 according to the embodiment of the present invention includes a controller 120 that controls charging of the charger 102, and a temperature sensor 121 that detects the temperature of the inverter 104 as power converter temperature detection means. And an outside air temperature sensor 122 as outside air temperature detecting means. The controller 120 controls the charger 102 based on the outside air temperature and the temperature of the inverter 104, thereby preventing an increase in temperature difference between when the inverter 104 is in operation and when it is not in operation due to charging of the next battery 103.

  The controller 120 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). It is also possible to configure the controller 120 with a plurality of microcomputers.

  With reference to FIG. 4, the charge control routine which the controller 120 performs for the above control is demonstrated.

  The controller 120 is programmed to charge the secondary battery 103 from the external power source 101 prior to the operation start time of the electric vehicle 1 input in advance by the driver. This routine is executed when the driver inputs the operation start time of the electric vehicle 1.

  When the routine is started, the controller 120 subtracts the time required for charging from the operation start time of the electric vehicle 1 in step S10, and further determines a charge start time with a sufficient allowance. The controller 120 also calculates the charging duration based on the current state of charge (SOC) of the secondary battery 103. Since these processes are known from the above-mentioned patent document 1, they are described as a subroutine in the figure and will not be described in detail.

  On the other hand, by charging the secondary battery 103 from the external power source 101, the controller 120 decreases the temperature of the inverter 104 in the non-operating state, and the temperature difference between when the inverter 104 is operating and when not operating increases. In order to prevent this, control from step S20 is performed.

  First, in step S20, the controller 120 predicts a change in the outside air temperature for the next 24 hours from the history of the outside air temperature detected by the outside air temperature sensor 122, and further predicts the minimum outside air temperature and the arrival time at the minimum outside air temperature. To do. The pattern of the change in the outside air temperature for the next 24 hours corresponds to the broken line 203 representing the change in the outside air temperature in FIG.

  Next, in step S30, the temperature change of the inverter 104 is predicted from the predicted outside air temperature change pattern. In FIG. 2, this corresponds to the one-dot chain line 205 representing the temperature change of the inverter 104 when the cooler 112 is not operated, that is, when the electric motor 105 is not operated and the secondary battery 103 is not charged. . The followability of the temperature of the inverter 104 with respect to the outside air temperature varies depending on the place where the inverter 104 is disposed in the electric vehicle 1. Therefore, how the temperature of the inverter 104 changes with respect to the change in the outside air temperature is modeled in advance by experiment or simulation. The controller 120 obtains the minimum temperature of the inverter 104 from the predicted temperature change and the current outside air temperature or the temperature of the inverter 104. In the following description, this temperature is referred to as the lowest temperature reached by the inverter 104.

  Next, in step S40, the controller 120 determines the temperature of the inverter 104 at the charging start time from the external power source 101 to the secondary battery 103 from the predicted temperature change pattern of the inverter 104 and the current outside air temperature or the temperature of the inverter 104. Ask for. In the following description, this temperature is referred to as a charging start temperature. Thus, by modeling the temperature change pattern of the inverter 104 based on the history of the outside air temperature detected by the outside air temperature sensor 122, it is possible to easily predict the minimum temperature reached and the charging start temperature.

  In the next step S50, the controller 120 calculates a temperature deviation between the charging start temperature and the lowest reached temperature. This corresponds to the maximum amount of temperature drop from the charging start time of the inverter 104 when the cooler 112 is not operating.

  In the next step S <b> 60, the controller 120 calculates the predicted temperature decrease due to the cooling of the inverter 104.

  The predicted temperature decrease amount is the maximum temperature decrease amount from the charging start time predicted by the cooler 112 when the cooler 112 cools the inverter 104. The predicted temperature decrease amount depends on the temperature difference between the outside air and the inverter 104 and the cooling time by the cooler 112. Here, the cooling time is equal to the charging duration determined in step S10. Therefore, a map of the predicted temperature decrease amount using the temperature difference and the charging duration as parameters is created by experiment or simulation, and stored in the ROM of the controller 120. The map is set so that the larger the temperature difference between the outside air at the start of charging and the inverter 104, the larger the predicted temperature decrease amount, and the longer the charging duration, the greater the predicted temperature decrease amount.

  In step S60, the controller 120 calculates a predicted temperature decrease amount by referring to a map of the predicted temperature decrease amount from the temperature difference between the outside air at the start of charging and the inverter 104 and the charge duration time.

  In step S70, the controller 120 compares the predicted temperature decrease calculated in step S60 with the temperature deviation calculated in step S50.

  When the predicted temperature decrease amount is equal to or less than the temperature deviation, even if the secondary battery 103 is charged from the external power source 101 over the charging duration from the charging start time, the inverter 104 cooled by the cooler 112 The temperature means that the temperature does not decrease to the lowest temperature of the inverter 104 when charging is not performed. In other words, it means that charging the secondary battery 103 does not cause an increase in the temperature difference between when the inverter 104 is in operation and when it is not in operation.

  In this case, in step S90, the controller 120 determines the charging schedule for the secondary battery 103 determined in step S10. As a result, the secondary battery 103 is charged based on the charging start time and the charging duration determined in step S10.

  On the other hand, if it is determined in step S70 that the predicted temperature decrease amount exceeds the temperature deviation, the secondary battery 103 is charged according to the charging start time and charging duration determined in step S10, and then the cooler 112 is charged. The temperature of the cooled inverter 104 is lower than the minimum temperature of the inverter 104 when the secondary battery 103 is not charged. In other words, if the secondary battery 103 is charged according to the charging schedule determined in step S10, the temperature difference between when the inverter 104 is in operation and when it is not in operation increases.

  In this case, the controller 120 performs any of the following temperature decrease avoidance processing in step S80 to correct the charging condition of the secondary battery 103.

  (1) The charging start timing from the external power source 101 to the secondary battery 103 is shifted.

  (2) The cooling capacity of the cooler 112 is lowered.

  The process (1) will be described. As a premise for explanation, FIG. 3 corresponds to the initial charging schedule of the secondary battery 103.

  Referring to FIG. 3, when the secondary battery 103 is charged under the initial charging schedule of the secondary battery 103 determined in step S <b> 10, the temperature of the inverter 104 reaches the minimum temperature 302. This is clearly below the minimum value of the broken line 201 that handles the temperature change of the inverter 104 when the secondary battery 103 is not charged. The controller 120 predicts this situation when the predicted temperature decrease exceeds the temperature deviation in the determination in step S70 of the routine of FIG. 4 executed in advance.

  In this case, the controller 120 delays the charging start time. From the temperature change pattern of the inverter 104 obtained in step S30, the temperature deviation between the charge start temperature and the lowest attained temperature can be calculated for each charge start time. If charging is started at a time when the temperature deviation exceeds the temperature drop amount of the inverter 104 being charged, the temperature drop amount of the inverter 104 being charged does not exceed the temperature deviation. The amount of temperature decrease can be obtained from the map as described above. The controller 120 shifts the charging start time by a certain time, calculates a temperature deviation and a temperature drop amount, and compares them to find a charge start time at which the temperature drop amount falls below the temperature deviation. This time is set as the charge start time after correction.

  Referring to FIG. 5, the initial charging start time of 0 o'clock is corrected to 4 o'clock by the above process. As a result of this correction, the secondary battery 103 is charged after the outside air temperature has started to rise. As a result, even if the cooler 112 is operated over the same charging duration, the temperature drop amount of the inverter 104 decreases, and the minimum temperature reached by the inverter 104 at the timing 402 in FIG. It becomes higher than the lowest temperature reached by the inverter 104 at the timing 302 of (b). In this way, by delaying the charging start time, it is possible to suppress the temperature drop of the inverter 104 caused by the cooling by the cooler 112.

  The process (2) will be described. Also in this case, FIG. 3 corresponds to the initial charging schedule of the secondary battery 103.

  When it is determined in step S70 that the predicted temperature decrease amount exceeds the temperature deviation, the controller 120 does not correct the charging start time and charging duration determined in step S10, and the output of the cooler 112 during the charging period. Add restrictions to

  The cooling capacity of the electric device 102 required for the charger / cooler 112 during charging of the secondary battery 103 depends on the outside air temperature. That is, if the outside air temperature during charging is low, the cooler 112 does not need to be fully operated. Therefore, the required output of the cooler 112 for maintaining the charger 102 in the allowable temperature range is calculated in advance according to the outside air temperature, and stored in the ROM of the controller 120 as a map.

  In step S80, the controller 120 refers to this map, obtains the required output of the cooler 112 from the outside air temperature, and reduces the output of the cooler 112 to the required output, with the charging start time determined in step S10. Then, the output of the cooler 112 is limited so that the secondary battery 103 is charged by the external power source 101 under the charging duration time.

  Referring to FIG. 6, the secondary battery 103 is charged from the same time as in FIG. 3 over the same time. However, output restriction is applied to the cooler 112. As a result, the minimum temperature that the inverter 104 reaches at the timing 502 in FIG. 3B is higher than the minimum temperature that the inverter 104 reaches at the timing 302 in FIG. In this way, by limiting the output of the cooler 112 during charging, it is possible to suppress the temperature drop of the inverter 104 caused by the cooling by the cooler 112.

  As described above, the cooler 112 that is charging the secondary battery 103 without changing the hardware such as the cooler 112 and the cooling passage 113 by the process (1) or (2) in step S80. Therefore, excessive cooling of the inverter 104 can be suppressed. In addition, it is also possible to combine the above processes (1) and (2) as the temperature decrease avoidance process in step S80.

  Regardless of whether the above processes (1) and (2) are performed in step S80, it is desirable to place the inverter 104 in the vicinity of the heat generating member that generates heat when the secondary battery 103 is charged. Examples of the heat generating member include a charger 102, a secondary battery 103, and electrical wiring that connects the charger 102 and the secondary battery 103.

  These members generate heat when the secondary battery 103 is charged, but do not generate heat when the secondary battery 103 is not charged. Therefore, while the secondary battery 103 is charged, it functions to prevent the temperature of the inverter 104 from dropping. However, when the electric motor 105 that requires cooling of the inverter 104 is operated, the cooling capacity of the inverter 104 by the cooler 112 is affected. Don't give. Arranging the inverter 104 in the vicinity of such a heat generating portion seat therefore has a favorable effect in suppressing the temperature drop of the inverter 104 caused by cooling by the cooler 112 during charging of the secondary battery 103.

  In addition, due to the operation of the electric motor 105, charges are accumulated in the capacitor in the inverter 104. If the electric charge is discharged through a heating element provided in the vicinity of the inverter 104 at the end of the operation of the electric motor 105, the temperature drop of the inverter 104 after the operation of the electric motor 105 can be delayed.

  In addition, in the prediction of the minimum reached temperature and the charging start temperature performed by the controller 120, in addition to the temperature sensor 121 and the outside air temperature sensor 122, the position information from the GPS 123 that acquires the position information of the electric vehicle 1 may be added. preferable. When the electric vehicle 1 moves between regions having a long distance or a large difference in altitude, the prediction accuracy decreases if the minimum temperature reached or the temperature at the start of charging is predicted only with the history of detection values of the outside air temperature sensor 122. By correcting the temperature change pattern of the inverter 104 based on the position information, the prediction accuracy in such a case can be improved.

  Furthermore, it is also preferable to use weather information data provided from the outside in the prediction of the lowest temperature reached and the temperature at the start of charging performed by the controller 120. The weather information data is received by the receiving device 124 mounted on the electric vehicle 1. As a result, the lowest temperature reached and the temperature at the start of charging can be predicted with high accuracy without using the temperature sensor 121 and the outside air temperature sensor 122.

  In the flow chart of FIG. 4, step S10 is a setting means, step S30 is a minimum reached temperature prediction means, step S40 is a charging start temperature prediction means, step S50 is a temperature deviation calculation means, and step S60 is a temperature drop. Step S70 constitutes a comparison means, step S80 constitutes a charging condition correction means, and S90 constitutes a charger control means.

  As described above, the present invention has been described through specific embodiments. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications or changes to these embodiments within the scope of the claims.

  For example, although the above embodiment is directed to the electric vehicle 1, the present invention uses the electric motor 105, the secondary battery 103 that supplies electric power to the electric motor 105 via the power converter 104, and the external power source 101. The present invention can be applied to any electric vehicle including a charger 102 that charges the secondary battery 103 and a cooler 112 that simultaneously cools the power converter 104 and the charger 102 while the secondary battery 103 is being charged. . Electric vehicles include so-called plug-in plug-in hybrid drive electric vehicles.

  In the above embodiment, the power converter is configured by the inverter 104. However, the present invention is not limited to the inverter 104 and can be applied to any power converter that can control the supply current to the electric motor 105. Moreover, although the secondary battery 203 is used for the charging device in the above embodiment, it is also possible to use, for example, a capacitor other than the secondary battery 203 for the charging device.

DESCRIPTION OF SYMBOLS 1 Electric vehicle 101 External power supply 102 Charger 103 Secondary battery 104 Inverter 105 Electric motor 106 Charging port 112 Cooler 113 Cooling path 120 Controller 122 Outside air temperature sensor

Claims (9)

An electric motor for traveling, a charging device that supplies electric power to the electric motor via a power converter, a charger that charges the charging device using an external power source, and the power converter and the charging device during charging of the charging device A drive device for an electric vehicle comprising a cooler for simultaneously cooling the cooler,
Setting means for setting the charging start time and charging duration of the charging device;
Charger control means for controlling the charger to charge the charging device using an external power source based on the set charging start time and charging duration time;
A minimum temperature predicting means for predicting the minimum temperature of the power converter when the cooler is not in operation;
Charging start temperature prediction means for predicting the temperature of the power converter at the charging start time as the charge start temperature;
A temperature deviation calculating means for calculating a temperature deviation between the predicted temperature at the start of charging and the lowest attained temperature;
A temperature drop prediction means for predicting a temperature drop of the power converter during the charging duration; and
A comparison means for comparing the temperature drop amount with the temperature deviation;
Charging condition correcting means for correcting the charging condition so that the amount of temperature decrease is reduced when the temperature decrease amount exceeds the temperature deviation;
A drive device for an electric vehicle, comprising:   The drive device for an electric vehicle according to claim 1, wherein the charging condition correcting means is charging start time changing means for changing the charging start time.   The drive device for an electric vehicle according to claim 2, wherein the charging start time changing means is configured to change the charging start time so that the charging is started after an outside air temperature reaches a minimum temperature.   The drive device for an electric vehicle according to claim 1, wherein the charging condition correcting means is a cooler output reducing means for reducing an output of the cooler during the charging period.   Outside temperature detecting means for detecting outside air temperature is further provided, and the minimum reached temperature predicting means is configured to determine the minimum reached temperature of the power converter in a non-operating state of the cooler based on the history of outside air temperature detected by the outside air temperature detecting means. 5. The electric motor according to claim 1, wherein the charging start temperature prediction means is configured to predict the charge start temperature based on a history of an outside air temperature detected by an outside air temperature detection means. Vehicle drive device.   It further comprises position detecting means for detecting the current position of the electric vehicle, wherein the lowest reached temperature predicting means adds a correction based on the current position to the prediction of the lowest reached temperature, and the charge start temperature predicting means is the charge start temperature The drive device for an electric vehicle according to claim 6, wherein the drive device is configured to add a correction based on the current position to the prediction of the vehicle.   Weather information acquisition means for acquiring weather information from the outside is further provided, wherein the lowest arrival temperature prediction means predicts the lowest arrival temperature based on weather information, and the charging start temperature prediction means is based on weather information when the charging start time The drive device of the electric vehicle according to claim 1, wherein the drive device is configured to predict a temperature.   The power converter includes an electronic component having a joint or solder to which stress due to a temperature change is loaded, and a charger for charging the joint or the solder to a charging device using an external power source. The drive device for an electric vehicle according to any one of claims 1 to 8, which is disposed in the vicinity of the heat generating portion. An electric motor for traveling, a charging device that supplies electric power to the electric motor via a power converter, a charger that charges the charging device using an external power source, and the power converter and the charging device during charging of the charging device A drive device for an electric vehicle comprising a cooler for simultaneously cooling the cooler,
Set the charging start time and charging duration of the charging device,
Based on the set charging start time and charging duration, the charger is controlled to charge the charging device using an external power source,
Predict the lowest temperature reached by the power converter when the cooler is not in operation,
Predicting the temperature of the power converter at the charge start time as the charge start temperature,
Calculate the temperature deviation between the estimated temperature at the start of charging and the lowest temperature reached,
Predicting the temperature drop of the power converter during the charging duration;
Comparing the temperature drop amount and the temperature deviation;
When the temperature decrease amount exceeds the temperature deviation, the charging condition is corrected so that the temperature decrease amount is reduced.
An electric vehicle driving method characterized by the above.

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