JP2022116393A - Charging system for electric vehicle - Google Patents

Abstract

To provide a charging system, mounted on an electric vehicle comprising an engine and an electric motor, which prevents a driver from having a feeling of strangeness when the electric vehicle travels after charging.SOLUTION: There is provided a charging system (20) for an electric vehicle (1) mounted on the electric vehicle comprising an engine (3) which is an internal combustion engine, an electric motor (5) which generates power for driving and a drive battery (7) supplying electric power to the electric motor. The charging system has: a charger (22) which charges the drive battery through an external power source; a drive tendency storage section (25) which stores past drive tendency in an operation start period; and a charging control section (23) which controls a temperature of the drive battery so that the temperature of the drive battery after a completion of charging becomes equal to a target temperature (TS). The charging control section (23) calculates the target temperature so that driving after the completion of the charging does not cause the temperature of the drive battery (7) to reach a temperature (TI) which requires output restriction on the basis of the drive tendency and a warm-up state of the engine.SELECTED DRAWING: Figure 1

Description

The present invention relates to a charging system mounted on an electric vehicle including an internal combustion engine and an electric motor.

2. Description of the Related Art There is an electric vehicle equipped with a charger that receives power from an external power source to charge a running battery. During charging, the temperature of the running battery rises. Further, when the electric motor is driven after charging, the temperature of the driving battery further rises. When the temperature of the battery for driving reaches the limit temperature, the output of the battery for driving is limited, and the power corresponding to the driving demand cannot be obtained, giving the driver a sense of discomfort.

Patent Literature 1 discloses a charging system that controls the upper limit temperature of the driving battery during charging so that the above-described output limitation does not occur during operation after charging is completed. Furthermore, the charging system of Patent Document 1 predicts the temperature rise after the end of charging from the power output status after the end of past charging, and determines the upper limit temperature of the driving battery during charging in consideration of the predicted temperature rise. .

JP 2015-171208 A

Even in an electric vehicle having an internal combustion engine and an electric motor for driving, if the temperature of the battery for driving reaches the limit temperature before the completion of engine warm-up, the power corresponding to the driving demand cannot be obtained. This may cause the driver to feel uncomfortable. This is because the output of the engine is limited until the warm-up is completed, and when the limit temperature is reached, the output of the driving battery is limited, which limits the auxiliary output of the electric motor. .

The present invention provides a charging system installed in an electric vehicle that includes an internal combustion engine and an electric motor for running, and is capable of suppressing a feeling of strangeness given to the driver during running after charging is completed. intended to provide

A charging system for an electric vehicle according to one aspect of the present invention includes:
A charging system for an electric vehicle mounted on an electric vehicle including an engine that is an internal combustion engine, an electric motor that generates power for running, and a battery for running that supplies electric power to the electric motor,
a charger that receives an external power supply to charge the running battery;
a driving tendency storage unit that records the past driving tendency during the driving start period;
a charging control unit that controls the temperature of the driving battery so that the temperature of the driving battery at the end of charging reaches a target temperature;
with
The charge control unit calculates the target temperature based on the driving tendency and the warm-up state of the engine so that the temperature of the driving battery does not reach a temperature at which output limitation occurs during operation after charging is completed. characterized by

Advantageous Effects of Invention According to the present invention, in a charging system mounted on an electric vehicle that includes an internal combustion engine and an electric vehicle motor for running, it is possible to prevent the driver from feeling uncomfortable during running after charging is finished. .

1 is a block diagram showing an electric vehicle and a charging system according to an embodiment of the invention; FIG. FIG. 3 is a diagram showing an output map of a driving battery stored in a map storage unit; FIG. FIG. 4 is a diagram showing an internal resistance map of a running battery stored in a map storage unit, (A) showing an internal resistance map used during charging using a DC power supply, and (B) showing a charging using an AC power supply; 1 shows an internal resistance map sometimes used. 4 is a time chart showing changes in the temperature of the driving battery from charging to driving. 4 is a flow chart showing temperature control processing of the driving battery executed by the charging control unit;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an electric vehicle and charging system according to an embodiment of the invention. The electric vehicle 1 includes drive wheels 2, an engine 3 that is an internal combustion engine, an auxiliary machine 4 that drives the engine 3, an electric motor 5 that generates power for running, an inverter 6 that drives the electric motor 5, A driving battery 7 that supplies electric power for driving to the inverter 6, a driving operation unit 8 that the driver performs driving operation, and driving control that receives operation signals from the driving operation unit 8 and controls the auxiliary machine 4 and the inverter 6. and a charging system 20 that charges the running battery 7 using an external power supply. The driving operation unit 8 includes at least an accelerator pedal for accelerator operation and a brake pedal for brake operation.

The travel control unit 9 is composed of one ECU (Electronic Control Unit) or a plurality of ECUs that operate in cooperation with each other through communication. The travel control unit 9 receives an operation signal from the driving operation unit 8, calculates a required output (the output may be read as torque) corresponding to the driving operation, and calculates the required output from the engine 3, the electric motor 5, or both. The auxiliary machine 4 and the inverter 6 are controlled so that Through such control, the power corresponding to the required output is sent to the drive wheels 2, and the vehicle travels according to the driving operation.

The electric vehicle 1 is further provided with a temperature sensor 3 a that detects the warm-up state of the engine 3 . The temperature sensor 3a may be configured to detect the temperature of the coolant of the engine 3, for example. A detected value of the temperature sensor 3 a is sent to the travel control unit 9 . The warm-up state of the engine 3 may include the warm-up state of various parts of the engine 3, and may include the warm-up state of the exhaust purification catalyst 3b of the engine 3, for example. The travel control unit 9 determines whether the engine 3 is warmed up based on the value detected by the temperature sensor 3a, and limits the output of the engine 3 when the engine 3 is not yet warmed up. When the output of the engine 3 is limited and power greater than the limited output is requested, the travel control unit 9 assists the electric motor 5 to drive the requested power. to output In this embodiment, the warm-up state of the exhaust purification catalyst 3b is applied as the warm-up state of the engine 3. FIG.

The running battery 7 is provided with a battery management unit 7a that monitors SOC (State of Charge) and temperature, and information on SIC and temperature is sent to the running control unit 9 from the battery management unit 7a. Based on the information, the travel control unit 9 limits power running of the electric motor 5 when the SOC (remaining charge) of the travel battery 7 is low, and restricts power running of the electric motor 5 when the SOC of the travel battery 7 is high. Limit regenerative operation. Furthermore, based on the temperature information of the battery 7 for driving, the driving control unit 9 restricts the output of the electric motor 5 according to the temperature when the temperature is high. The running battery 7 is provided with a cooler 7b (such as a cooling fan) that can be controlled by the charge controller 23 .

<Charging system>
The charging system 20 includes a charging connector 21 having an AC charging connector 21a to which an AC power plug 51 can be connected and a DC charging connector 21b to which a DC power plug 52 can be connected. A charger 22 that outputs a charging current and a charging controller 23 that controls the charger 22 are provided. The AC power plug 51 is supplied with power from, for example, a household AC 100V AC power supply. The DC power supply plug 52 is supplied with power from a DC power supply such as a DC 200V to DC 800V dedicated for charging, for example. Hereinafter, charging of the running battery 7 via the charging connector 21 will be referred to as "plug-in charging", charging using the DC power plug 52 will be referred to as "DC charging", and charging using the AC power plug 51 will be referred to as "DC charging". It is called "AC charging". During AC charging, it is possible to perform timer charging in which the battery is fully charged at a time set by the user. During DC charging, rapid charging is possible up to a predetermined SOC (for example, 80%).

The charging control unit 23 is composed of one ECU (Electronic Control Unit) or a plurality of ECUs that operate in cooperation with each other through communication. Information on the temperature, SOC, and deterioration of the driving battery 7 is sent from the battery management unit 7a to the charging control unit 23, and detection information is sent from the temperature sensor 3a of the engine 3 to the charge control unit 23.

The charging system 20 is further provided with a map storage unit 24 that stores various map data used by the charging control unit 23 and a driving tendency storage unit 25 that records information on the driving tendency of the electric vehicle 1 . The map storage unit 24 stores an output map 240 in which the predetermined SOC of the running battery 7 and the output limit power for each arbitrary temperature are registered, and an output map 240 used for estimating the internal resistance of the running battery 7 during DC charging. and a second internal resistance map 242 used for estimating the internal resistance of the running battery 7 during AC charging.

<Recording of driving tendencies>
The travel control unit 9 records information indicating past driving tendencies in the driving start period in the driving trend storage unit 25 . The operation start period is a period of a predetermined length (for example, 5 minutes to 30 minutes) from the start of the electric vehicle 1 . The recording of driving tendency information may be performed during each operation start period, may be performed only during an arbitrarily selected operation start period, or may be performed only during the operation start period immediately after the end of charging. . The driving tendency information may be recorded so as to identify which driver has the driving tendency, or may be recorded regardless of the driver. In order to identify which driver's driving tendency, for example, a camera is placed facing the driver's seat, the driver is identified from the image of the camera, and the driving tendency information is recorded in association with the driver's identification information. do it. Various other methods may be adopted as the driver identification method. The information indicating the driving tendency to be recorded may be information indicating the tendency of accelerating driving, or may be information including the tendency of driving other than acceleration. The information indicating the driving tendency to be recorded may be information about the driving tendency throughout the driving start period, or may be information about the maximum load within the driving start period. The information on the driving tendency to be recorded may be any information that can predict the tendency of the driving load during the operation start period.

<Characteristics of driving battery - output map>
A maximum output power is set for the running battery 7 in order to avoid rapid deterioration of the battery. For the same reason, when the temperature of the running battery 7 is equal to or higher than a predetermined temperature, the output limit power is set according to the SOC and the temperature. The travel control unit 9 controls the output of the electric motor 5 so that the output power of the travel battery 7 does not exceed the maximum output power and the output limit power. The output limit power corresponding to the SOC and temperature is registered as map data and stored so as to be readable from the travel control unit 9 .

FIG. 2 is a diagram showing a driving battery output map stored in a map storage unit. In the output map 240 stored in the map storage unit 24, output limit power is registered at SOC (for example, 80% to 100%) at the end of charging and for each arbitrary temperature. In the example of FIG. 2, when the temperature is 45° C. or less, it is shown that the driving battery 7 can output electric power equal to or less than the maximum output power (200 kW). It is shown that the battery 7 can output electric power equal to or lower than the output limit electric power (0 kW to 58 kW) corresponding to each temperature value.

<Characteristics of driving battery - internal resistance map>
The internal resistance of the running battery 7 varies depending on the degree of deterioration, SOC, and temperature. The degree of deterioration is managed by the battery management unit 7a. The degree of deterioration varies depending on various conditions such as the number of charge/discharge cycles, charge/discharge conditions, and aging. , is estimated by the battery management unit 7a.

When the rapid charging (DC charging) ends, the SOC of the running battery 7 becomes the first value (for example, 80%). On the other hand, when AC charging ends with full charging, the SOC of the running battery 7 becomes a second value (for example, 100%) higher than the first value. Therefore, in order to estimate the internal resistance of the running battery 7 at the end of charging, map data corresponding to the SOC at the end of DC charging and map data corresponding to the SOC at the end of AC charging are required.

FIG. 3 is a diagram showing an internal resistance map of the running battery stored in the map storage unit, (A) showing an internal resistance map used during charging using a DC power supply, and (B) showing an AC power supply map. shows an internal resistance map used when charging with The first internal resistance map 241 stored in the map storage unit 24 is map data corresponding to the SOC at the end of quick charging (DC charging). The first internal resistance map 241 indicates the internal resistance of the running battery 7 at an arbitrary degree of deterioration and at an arbitrary temperature at the SOC. The second internal resistance map 242 is map data corresponding to the SOC at the end of timer charging (AC charging). The second internal resistance map 242 indicates the internal resistance of the running battery 7 at an arbitrary degree of deterioration and at an arbitrary temperature at the SOC.

<Temperature control during charging>
During timer charging (AC charging) or rapid charging (DC charging), the charging control unit 23 controls the temperature of the driving battery 7 at the end of charging to a target temperature _TS . This control may be realized by adjusting the strength of the cooler 7b of the running battery 7 at the end of charging, or by adjusting the charging current at the end of charging. It may be realized by using them together. In this embodiment, the temperature of the running battery 7 is controlled by adjusting the strength of the cooler 7b.

The charging control unit 23 calculates the target temperature T _S of the driving battery 7 at the end of charging so as to prevent the driver from feeling uncomfortable during driving after charging is finished (for example, driving immediately after charging is finished). do. That is, if the driving tendency of the electric vehicle 1 in the operation start period is a high load operation, it is predicted that the same load driving operation will be performed in the operation start period after the end of charging. Furthermore, if the degree of warm-up of the engine 3 is low, the time from the start of operation to the completion of warm-up of the engine 3 will be extended, during which the output of the engine 3 will be restricted and the electric motor 5 will perform auxiliary output. will be When the electric motor 5 produces an auxiliary output, Joule heat is generated in the running battery 7 according to the output current and internal resistance of the running battery 7 , and the temperature of the running battery 7 rises. Due to this temperature rise, if the temperature of the running battery 7 reaches the limit temperature before the warm-up of the engine 3 is completed, the output of the running battery 7 and the electric motor 5 is limited, and the operation is stopped. The power corresponding to the operation cannot be obtained, and the driver feels uncomfortable.

Therefore, the charging control unit 23 determines whether the running battery is charged during operation after charging is finished, based on the driving tendency in the past driving start period, the warm-up state of the engine 3, and the type of the external power supply used for plug-in charging. Calculate the above target temperature T _S so that the temperature of 7 does not reach the limit temperature. The reason for using the type of external power source is that the SOC at the end of charging differs depending on whether it is rapid charging (DC charging) or AC charging, and the internal resistance of the running battery 7 differs depending on the SOC.

<Parameters for calculating and controlling the target temperature>
FIG. 4 is a time chart showing changes in the temperature of the running battery from charging to running. In the time chart, the solid line indicates the case where the control of the charging system 20 of the present embodiment works, and the dashed line indicates the case where the control does not work.

As shown in the time chart of FIG. 4, the charging control unit 23 performs the following operations to calculate the target temperature _TS or to control the temperature of the driving battery 7 to the target temperature _TS . Use parameters.
T _I : Estimated temperature of the driving battery 7 at which it is predicted that the output of the driving battery 7 will be limited when driving according to the past driving tendency is performed after the end of charging t _{_} start _{_} run : After the end of charging Predicted period until warm-up of the engine 3 is completed due to driving ΔT: It is predicted that the temperature of the driving battery 7 will rise due to driving during the period from the end of charging to the _elapse of the predicted period _{t_start_run} . amount (predicted temperature rise)
T _S : Target temperature of the driving battery 7 at the end of charging t_last_chg: Temperature control period set to control the driving battery 7 to the target temperature T _S at the end of charging

<Method for calculating predicted temperature _TI at which output limitation occurs>
When the output of the engine 3 is limited due to pre-warming up, if a driving operation is performed with a large accelerator opening (the amount of operation of the accelerator pedal), the output of the engine 3 is insufficient for the running battery 7. and the electric motor 5. If the requested output is greater than the output limit power shown in the output map of FIG. 2, the outputs of the battery 7 for running and the electric motor 5 are limited.

Therefore, when calculating the predicted temperature _TI , the charge control unit 23 first predicts what kind of load driving operation will be performed after the end of charging, based on the information in the driving tendency storage unit 25 . For example, the maximum accelerator opening at the time of driving, for example, the statistical amount of the accelerator opening during the past driving start period (for example, its maximum value, the average of the maximum values for the past multiple driving start periods, or the full accelerator opening ), and the load corresponding to the maximum accelerator opening is defined as the predicted load. Next, the charging control unit 23 subtracts the maximum output of the engine 3 before warm-up from the predicted load, and obtains the required output of the battery 7 for driving and the electric motor 5 . Then, using the output map 240 of FIG. 2, the temperature at which the required output becomes the output limit power is collated, and the temperature is obtained as the predicted temperature _TI at which the output limit occurs.

For example, if the maximum output during operation after completion of charging predicted from past driving trends is 143 kW, and the maximum output of the engine 3 before warming up is 100 kW in terms of electric power, the driving battery 7 is required to The output is expected to be 43 kW. According to the output map 240, the temperature of the running battery 7 at which the maximum output is 43 kW is 53.degree. Therefore, in this case, the predicted temperature _TI is 53°C.

It should be noted that the timing at which whether or not the output of the running battery 7 will be limited is not the timing at the end of charging, but the subsequent timing during driving. Therefore, it is assumed that the SOC of the running battery 7 is slightly lower than that at the end of charging. However, in the method of calculating the predicted temperature _TI described above, the decrease in SOC is ignored as being very small compared to the capacity of the running battery 7 . If the capacity of the running battery 7 is small and the decrease in SOC cannot be ignored, the output map may be collated in consideration of the decrease in SOC. In any case, it is possible to obtain the predicted temperature _TI at which the driving battery 7 will be limited in output.

<Method for calculating prediction period t_start_run>
The prediction period t_start_run is obtained by estimating the time required for the temperature of the engine 3 to rise from the temperature at the start of operation due to the temperature rise associated with operation after the end of charging to the temperature at which warm-up is completed. Therefore, first, the charging control unit 23 estimates the temperature of the engine 3 at the start of operation (that is, the temperature at the end of charging) based on the output of the temperature sensor 3a during plug-in charging. Here, the temperature of the engine 3 is, for example, the temperature of the exhaust purification catalyst 3b. The charging control unit 23 reads the value of the temperature sensor 3a when the engine 3 is completely cold, such as in the latter half of plug-in charging, and assumes that the temperature of the engine 3 does not change after that, and sets the temperature to the temperature at the end of charging. Alternatively, the temperature at the end of charging may be estimated more accurately by performing correction based on information such as the outside temperature, time of day, and weather forecast. Next, the charging control unit 23 applies the temperature rise pattern after the start of the engine 3 to the temperature after the end of charging, and calculates back the time until the temperature reaches the warm-up completion temperature. is obtained as the predicted period t_start_run until the completion of warm-up. The temperature rise pattern described above is obtained in advance by testing, simulation, or the like, and is stored in the charging control unit 23 .

Note that if there are uncertainties when calculating the predicted period t_start_run until the completion of warm-up, the charging control unit 23 adopts the worse condition (the longer the predicted period t_start_run) and performs the calculation. good too. For example, if the outside temperature after prediction until the end of charging is predicted to be 5°C to -5°C, -5°C is adopted. Due to the adoption of such an uncertain element condition, the time until the engine 3 actually completes warming up exceeds the prediction period t_start_run, and as a result, the output corresponding to the driving operation is limited. Such situations can be reduced.

<Method for calculating predicted temperature rise ΔT>
The predicted temperature rise ΔT is obtained by adding the temperature rise due to Joule heat generated in the driving battery 7 during operation after charging is completed and the temperature decrease due to heat radiation from the driving battery 7 to the external environment. The Joule heat is obtained from the predicted output current I and the predicted internal resistance R of the running battery 7 during operation after charging is completed. Furthermore, the temperature rise based on Joule heat can be obtained by dividing the Joule heat by the heat capacity C [W/° C.] of the running battery 7 . The temperature drop due to the above-described heat radiation is obtained as a value approximately proportional to the difference between the environmental temperature Tout around the driving battery 7 and the initial temperature (target temperature T _S ) of the driving battery 7 (heat radiation coefficient α times). . The heat capacity C of the running battery 7 and the heat radiation coefficient α representing the temperature drop according to the environmental temperature Tout are obtained in advance through tests, simulations, or the like, and stored in the storage unit of the charging control unit 23 .

Based on these facts, the charging control unit 23 performs approximation ignoring small differences, and obtains the predicted temperature rise ΔT as shown in the following equation (1).
ΔT={I ² R× _{t_start_run} /C _} −α{T _S −Tout} (1)

Here, the output current I may be obtained as one value from the average predicted output of the electric motor 5 during the prediction period t_start_run based on the information in the driving tendency storage unit 25, or may be obtained at each timing of the prediction period t_start_run. It may be determined as a function of varying time.

Further, the internal resistance R is calculated from the internal resistance map stored in the map storage unit 24 assuming that the temperature of the running battery 7 changes from the target temperature T _S to the vicinity of the predicted temperature T _I at which the output is limited. It is obtained by matching with the degree of deterioration. The internal resistance R may be obtained as one value by averaging the internal resistance during the prediction period t_start_run, or may be obtained as a function of time that changes at each timing.

When the output current I and the internal resistance R are obtained as a function of time, the charging control unit 23 calculates the Joule heat generated in the prediction period t_start_run by time-integrating the calculated value of the power at each timing. good.

When estimating the internal resistance R, the charging control unit 23 uses the first internal resistance map 241 corresponding to DC charging when DC charging, and the second internal resistance map 241 corresponding to AC charging when AC charging. An internal resistance map 242 is used. Such switching of the internal resistance map can improve the calculation accuracy of the predicted temperature rise ΔT.

In the second term [α{T _S -Tout}] on the right side of equation (1), which expresses the temperature drop due to heat dissipation, the environmental temperature Tout and the temperature of the running battery 7 do not have a large error. The initial temperature at the end of charging is used. However, the environmental temperature Tout and the temperature of the running battery 7 in the second term may be obtained as a function of time, the values of which change at each timing of the prediction period t_start_run, instead of the initial temperatures. In this case, the charging control unit 23 may calculate the temperature drop due to heat dissipation by time-integrating the value of heat dissipation at each timing.

<How to calculate the target temperature _TS >
The target temperature _TS is obtained by subtracting the predicted temperature rise _ΔT from the predicted temperature TI at which output limitation occurs, as in the following equation (2).
T _S =T _I -ΔT (2)
The formula for the predicted temperature rise ΔT uses the target temperature T _S not only for the temperature drop term [α{T _S −Tout}] due to heat radiation, but also when the internal resistance R is obtained. Therefore, the formula (2) has a nest structure of the target temperature _TS , but the solution of the formula (2) can be easily obtained by numerical analysis or the like.

<Relationship between target temperature _TS and other states>
The relationship between the target temperature _TS and the operation tendency in the past operation start period is as follows. That is, when the driving tendency in the past operation start period is high load, the tendency is recorded in the driving tendency storage unit 25, and the predicted load used when calculating the predicted temperature _TI increases. As shown in the output map 240 of FIG. 2, the predicted temperature _TI decreases as the output limit power corresponding to the predicted load increases. Similarly, when the driving tendency in the past operation start period is high load, the driving tendency is recorded in the driving tendency storage unit 25, and the predicted output current I used when calculating the predicted temperature rise ΔT increases. Become. When the output current I is large, the generated Joule heat becomes large, and the predicted temperature rise ΔT becomes large. The target temperature _TS , the predicted temperature _TI , and the predicted temperature rise ΔT have the relationship of the above formula (2). The target temperature _TS is lower than when the load is low.

The relationship between the target temperature _TS and the degree of warm-up of the engine 3 is as follows. That is, when the degree of warm-up is low, the predicted period t_start_run from the end of charging to the completion of warm-up of the engine 3 due to operation becomes longer. The predicted period t_start_run is used in calculating the predicted temperature rise ΔT, and the predicted temperature rise ΔT increases as the predicted period t_start_run increases. Therefore, if other conditions are the same and the degree of warm-up of the engine 3 is low, the target temperature _TS will be lower than when the degree of warm-up is high.

<Temperature control period t_last_chg>
The temperature control period t_last_chg is set to have a margin in advance so that the temperature of the driving battery 7 can be lowered to the target temperature _TS even when the temperature difference from before the control to the target temperature _TS is large. . The temperature control period t_last_chg may be corrected so as to be shortened when the temperature of the running battery 7 is likely to be lowered, such as when the outside air temperature is low, and lengthened in the opposite case.

<Temperature control processing for running battery>
FIG. 5 is a flow chart showing temperature control processing of the running battery executed by the charge control unit. When the plug-in charging is started, the charging control unit 23 starts the temperature control process of FIG. 5 in parallel with the charging control. First, the charging control unit 23 determines whether or not there is a timer setting for plug-in charging (step S1), determines whether or not AC charging (step S2), determines whether or not DC charging (step S3). )I do. As a result, if it is AC charging with timer setting (timer charging), the charging control unit 23 applies the second internal resistance map as the internal resistance map used to obtain the internal resistance R (step S4). The end time is acquired from the timer setting (step S5), and the process proceeds to the subsequent step. On the other hand, in the case of DC charging (rapid charging) without timer setting, the charging control unit 23 applies the first internal resistance map as the internal resistance map used to obtain the internal resistance R (step S6), and ends charging. The time is acquired from the specified time for quick charging (step S7), and the process proceeds to the subsequent step.

In addition, in the case of DC charging with a timer setting or AC charging without a timer setting, the charge control unit 23 determines that the temperature control of the running battery 7 is unnecessary, and terminates the temperature control process.

Next, when the process proceeds, first, the charging control unit 23 starts cooling the running battery 7 in the normal mode (step S8), and the remaining charging time from the current time to the end of charging is less than the temperature control period t_last_chg. The processing (step S9) for determining whether the time is short is repeated until the determination result becomes YES.

Then, if the result of the determination in step S9 is YES, first, the charge control unit 23 controls the power supply of the driving battery whose output is predicted to be limited when the operation is performed in accordance with the past driving tendency after the end of charging. 7 predicted temperature _TI is calculated by the method described above (step S10). Further, the charging control unit 23 predicts a prediction period _{t_start_run} in which warm-up of the engine 3 is completed in the operation after charging is finished, and the running battery 7 from the end of charging to the elapse of the prediction period _{t_start_run} . The temperature rise ΔT is calculated by the method described above (step S11). Further, the charging control unit 23 sets the target temperature T _S at which the driving battery 7 at the end of charging almost reaches the predicted temperature T _I at which the output is limited due to the subsequent temperature rise of the predicted rising temperature ΔT. (step S12). Then, the charging control unit 23 determines whether the current temperature of the driving battery 7 is higher than the target temperature _TS (step S13), and if YES, switches the cooling control of the driving battery 7 to the high power mode (step S14). ). On the other hand, if the determination result in step S13 is NO, the charge control unit 23 switches the cooling control of the driving battery 7 to the normal mode (step S15). Then, after step S14 or step S15, the charging control unit 23 determines whether or not charging has ended (step S16). If NO, the process returns to step S13. If YES, the temperature control process ends. .

According to the temperature control process described above, the target temperature _TS is calculated immediately before the temperature control period t_last_chg at the end of charging, and the temperature of the running battery 7 is calculated by the subsequent loop process (steps S13 to S16). It is controlled to the target temperature _TS .

In the temperature control process described above, the predicted temperature _TI , the predicted period _{t_start_run} , the predicted temperature rise ΔT, and the target temperature _TS are calculated only once immediately before the temperature control period _{t_last_chg} . However, the above calculation uses predicted temperatures of the driving battery 7 and the engine 3 after the end of charging. Therefore, if the above calculation is performed near the end of charging, the predicted value of the temperature will be more accurate, and the accuracy will increase. Therefore, the charging control unit 23 repeats the above calculations in the loop processing of steps S13 to S16, and based on the latest calculation result, performs temperature control so that the driving battery 7 reaches the target temperature _TS . may

<Operation after charging>
As indicated by the dashed line in FIG. 4, without temperature control, the temperature of the running battery 7 is maintained at a relatively high temperature T11 at time t1 at the end of the plug-in charging period J1 due to the temperature rise due to charging. Then, it is assumed that, in the operating period J2, a load driving operation is performed that results in an insufficient output of the engine 3 that has not yet been warmed up. Then, during the prediction period t_start_run until the warm-up of the engine 3 is completed, the auxiliary output is provided from the electric motor 5, so the temperature of the running battery 7 rises according to the output. Before timing t2 at which warm-up of the engine 3 is completed, the temperature of the driving battery 7 reaches the predicted temperature _TI at which the output is limited (timing t11). Therefore, in the subsequent period J21, the power corresponding to the driving request cannot be output, and the driver feels uncomfortable.

On the other hand, as shown by the solid line in FIG. 4, temperature control is performed so that the running battery 7 is cooled at the end of plug-in charging (temperature control period t_last_chg), and the temperature of the running battery 7 is reduced at the end of charging t1. is controlled to the target temperature _TS . Then, in the operation period J2, similarly to the above, it is assumed that a load driving operation (an operation with a driving tendency predicted based on the information of the driving tendency storage unit 25) that results in an insufficient output with only the engine 3 that has not yet warmed up is performed. . Then, an auxiliary output is generated from the electric motor 5, and the temperature of the running battery 7 rises. However, the temperature rising toward the timing t2 when the warm-up of the engine 3 is completed becomes the predicted temperature rise ΔT predicted based on the past driving tendency.

The predicted temperature rise ΔT is set so that the temperature of the driving battery 7 does not exceed the predicted temperature _TI at the warm-up completion timing t2 even when the driving tendency is accurately predicted, and It is calculated so that the temperature is close to the predicted temperature _TI . Preferably, the temperature of the driving battery 7 at the warm-up completion timing t2 is within the range H1 of 90% to 100% of the temperature at which the output limitation occurs when the same driving operation as the past driving tendency is performed. , the predicted temperature rise ΔT is calculated.

Therefore, the temperature of the driving battery 7 is prevented from reaching the predicted temperature _TI at which the output is limited before timing t2 at which warm-up is completed. Then, the warm-up of the engine 3 is completed (timing t2) without the output limitation of the running battery 7 and the electric motor 5, and the output limitation of the engine 3 is released. output is reduced, and the temperature of the running battery 7 is lowered. Therefore, it is possible to prevent the driver from feeling uncomfortable due to the inability to output the motive power corresponding to the driving request in the operation after the end of charging.

As described above, according to the charging system 20 of the present embodiment, the driving tendency storage unit 25 that records the past driving tendency during the operation start period and the temperature of the driving battery 7 at the end of charging reach the target temperature _TS . and a charging control unit 23 that controls charging of the driving battery so that the driving battery is charged. Based on the driving tendency recorded in the driving tendency storage unit 25 and the warm-up state of the engine 3, the charging control unit 23 determines that the temperature of the driving battery 7 is the temperature at which the output is limited during operation after charging is completed. Calculate the target temperature T _S so as not to reach Therefore, in a situation where the engine 3 has not yet warmed up and the electric motor 5 is producing an auxiliary output, the output of the running battery 7 will be limited when the same operation tendency as in the past is performed after charging is completed. A rise to the imposed temperature is suppressed. Therefore, it is possible to prevent a situation in which output limitations are imposed on both the engine 3 and the electric motor 5 and the driver feels uncomfortable.

Furthermore, according to the charging system 20 of the present embodiment, when only the past driving tendency in the operation start period is different, the charging control unit 23 increases the load at the end of charging as the driving tendency is higher. The target temperature _TS of the running battery 7 is calculated to be low. Further, when only the warm-up state of the engine 3 is different, the charging control unit 23 calculates the target temperature _TS of the driving battery 7 at the end of charging to be lower as the degree of warm-up is lower. Normally, it is assumed that the higher the load in the past driving tendency in the operation start period, the higher the load driving operation is performed in the operation after the end of charging, and the higher the temperature rise rate of the driving battery 7 is. Further, it is assumed that the lower the degree of warm-up of the engine 3, the longer the auxiliary output period of the electric motor 5 at the end of charging, and the longer the period during which the temperature of the driving battery 7 rises. Therefore, in relation to the driving tendency as described above or in relation to the warm-up state of the engine 3, the target temperature _TS is calculated to be low. It is possible to prevent the output of the running battery 7 from being limited due to temperature rise during the normal output period.

Furthermore, according to the charging system 20 of the present embodiment, the charging control unit 23 is capable of DC charging and AC charging, and the charging control unit 23 controls the running time at the end of charging based on the power source type of plug-in charging. A target temperature T _S of the battery 7 is calculated. Since the SOC of the driving battery 7 is different between when DC charging is completed and when AC charging is completed, a difference occurs in the internal resistance of the driving battery 7, and a similar current output is produced during operation after charging is completed. Even if it is done, the amount of temperature rise will be different. Therefore, the charging control unit 23 should also consider the type of power source for plug-in charging and calculate the target temperature _TS so that the temperature of the driving battery 7 does not reach the temperature at which the output limitation occurs during operation after charging is completed. Therefore, a more appropriate target temperature _TS can be obtained, and the above-described situation in which the driver feels uncomfortable can be further suppressed.

Furthermore, according to the charging system 20 of the present embodiment, the charging control unit 23 corresponds to the first internal resistance map 241 corresponding to DC charging in the case of DC charging, that is, to the SOC (for example, SOC 80%) at the end of DC charging. The target temperature _TS is calculated using the first internal resistance map 241 obtained. In addition, the charging control unit 23 uses the second internal resistance map 242 corresponding to AC charging, that is, the second internal resistance map 242 corresponding to the SOC (for example, SOC 100%) when AC charging is completed. Calculate the target temperature _TS . Therefore, the charging control unit 23 can calculate the target temperature _TS considering the power supply type of plug-in charging with less data and calculation load, and appropriately reflect the difference based on the power supply type in the target temperature _TS . can do.

Furthermore, according to the charging system 20 of the present embodiment, after the end of charging, when the load that matches the past driving tendency in the driving start period recorded in the driving tendency storage unit 25 is performed, that is, when the charging ends When the subsequent operation can be accurately predicted, the temperature of the driving battery 7 at the completion of warm-up of the engine 3 is a temperature close to the predicted temperature _TI without exceeding the predicted temperature _TI at which output limitation occurs ( The target temperature T _S is calculated so as to be within the range H1 (FIG. 4) of 90% to 100% of the predicted temperature T _I. Therefore, the temperature of the driving battery 7 at the end of charging is not lowered more than necessary, and conversely, the output of the driving battery 7 is restricted due to the low temperature, and the driving battery 7 is cooled more than necessary before charging is finished. loss can be suppressed.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. For example, in the above embodiment, the charging system 20 has a configuration capable of both AC charging and DC charging, but the charging system according to the present invention may have a configuration capable of only one. The charge controller may be configured to calculate the target temperature corresponding to one of the power supply types. Further, in the above-described embodiment, an example in which the warm-up state of the exhaust purification catalyst 3b is applied as the warm-up state of the engine 3 is shown. A warm-up state may be applied as the warm-up state of the engine 3 . Other details shown in the embodiments can be changed as appropriate without departing from the scope of the invention.

Reference Signs List 1 electric vehicle 2 drive wheel 3 engine 5 electric motor 7 running battery 7a battery management section 8 driving operation section 20 charging system 21 charging connector 22 charger 23 charging control section 24 map storage section 240 output map 241 first internal resistance map 242 Second internal resistance map 25 Driving tendency storage unit t_last_chg Temperature control period _{t_start_run} Predicted period until completion of warm-up T Predicted temperature at which the output of the battery for driving will be limited ΔT Predicted rising temperature T _S target temperature

Claims (5)

A charging system for an electric vehicle mounted on an electric vehicle including an engine that is an internal combustion engine, an electric motor that generates power for running, and a battery for running that supplies electric power to the electric motor,
a charger that receives an external power supply to charge the running battery;
a driving tendency storage unit that records the past driving tendency during the driving start period;
a charging control unit that controls the temperature of the driving battery so that the temperature of the driving battery at the end of charging reaches a target temperature;
with
The charge control unit calculates the target temperature based on the driving tendency and the warm-up state of the engine so that the temperature of the driving battery does not reach a temperature at which output limitation occurs during operation after charging is completed. A charging system for an electric vehicle, characterized by: The charging control unit
when only the operating tendency is different, the target temperature is calculated lower as the operating tendency is a higher load tendency;
2. The electric vehicle charging system according to claim 1, wherein when only the warm-up state is different, the target temperature is calculated to be lower as the degree of warm-up is lower. the charger is capable of inputting AC power and inputting DC power;
The charging control unit further calculates the target temperature based on the type of power supply input to the charger so that the temperature of the driving battery does not reach a temperature at which output limitation occurs during operation after charging is completed. The charging system for an electric vehicle according to claim 1 or 2, characterized in that: The charging control unit
Using a resistance map showing the relationship between the internal resistance of the running battery and the temperature, predicting the temperature rise of the running battery after completion of charging, and switching the resistance map based on the power supply type. 4. The charging system for an electric vehicle according to claim 3. The charging control unit
When the load that matches the driving tendency is operated after the end of charging, the temperature of the driving battery at the time when the warm-up of the engine is completed is 90% to 100% of the temperature at which the output limitation occurs. 5. The electric vehicle charging system according to any one of claims 1 to 4, wherein the target temperature is calculated so as to fall within a range.

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