JP6492430B2 - Control device for plug-in hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a plug-in hybrid vehicle including a motor and an engine, and a battery that can be charged from an external power source.

  Conventionally, in a plug-in hybrid vehicle that has an engine and a motor and is equipped with a battery that can be charged from an external power source, a control device for a plug-in hybrid vehicle that notifies a user when a problem occurs in an external charging system Is known (see, for example, Patent Document 1).

JP 2010-220299 A

By the way, the plug-in hybrid vehicle has a charge control circuit that controls electric power charged in the battery during charging of the battery. The charge control circuit generates heat as it is charged. However, when the circuit temperature rises, the voltage conversion efficiency decreases, which may increase the charging time or prevent charging from an external power source.
On the other hand, in the conventional plug-in hybrid vehicle control device, the voltage conversion efficiency in the charge control circuit decreases due to the temperature increase of the charge control circuit, the charge amount per unit time decreases, or the circuit temperature increases. When charging is interrupted, only the user is notified. For this reason, it has not been possible to solve the problem that the charging time is increased and the charging is interrupted without sufficiently securing the charging capacity.
In order to avoid the above phenomenon, it is conceivable to increase the amount of voltage conversion by increasing the volume of the charge control circuit, but this increases the circuit volume, dimensions, and weight, which affects the vehicle mountability. End up. In order to suppress the temperature rise of the charging control circuit during charging, it is conceivable to provide a heat sink in the charging control circuit, but this is not preferable from the viewpoints of downsizing, weight increase, cost increase, and the like.

  The present invention has been made paying attention to the above problem, and provides a control device for a plug-in hybrid vehicle capable of suppressing an increase in charging time when charging a battery from an external power source and improving the amount of charge. The purpose is to provide.

To achieve the above object, the present invention provides a motor as a travel drive source, a battery that stores electric power to be supplied to the motor, can be charged from an external power source, power generation means that charges the battery, An engine as a power generation drive source for driving the power generation means, and a charge control circuit that controls electric power charged in the battery and generates heat when the battery is charged, and the charge control circuit is connected to the engine from the engine. It is mounted on a plug-in hybrid vehicle arranged in a region affected by heat. A charging point setting unit, a charging capacity monitoring unit, a charging capacity determination unit, and an engine control unit are provided.
The charging point setting unit sets a charging point at which the battery can be charged from the external power source.
The charging capacity monitoring unit is configured such that the distance to the charging point reaches a temperature at which the charging control circuit can determine that the charging control circuit does not reach a charging limit temperature during charging by the external power supply before arrival at the charging point. When a predetermined SOC monitoring start distance that can secure a cooling period for cooling the battery is reached, the charge capacity of the battery is monitored.
The charge capacity determination unit sets an EV chargeable amount that is an amount that can be set in an EV mode in which the engine is stopped until the charge capacity of the battery reaches the charging point after reaching the SOC monitoring start distance. Determine whether it has been reached.
If the charge capacity of the battery is equal to or greater than the EV chargeable amount, the engine control unit is in the EV mode until reaching the charging point, and if the battery charge capacity is equal to or less than the EV chargeable amount, The engine is driven to drive the power generation means.

Therefore, in the control device for a plug-in hybrid vehicle according to the present invention, after reaching the SOC monitoring start distance, if the charge capacity of the battery is equal to or greater than the EV chargeable amount, the EV mode in which the engine is stopped until the charge point is reached. Run.
Therefore, even if the charge control circuit is disposed in a region that is affected by heat from the engine, the engine is stopped until the charging point is reached, so that an increase in circuit temperature due to the heat effect of the engine can be reliably prevented. That is, the temperature increase of the charge control circuit can be suppressed before charging the battery from the external power supply.
As a result, the circuit temperature at the start of charging can be prevented from becoming high, and even if the circuit temperature rises due to charging, the voltage conversion efficiency can be prevented from lowering quickly or reaching the charge limit temperature. it can. As a result, it is possible to suppress an increase in charging time when charging the battery from the external power source and to improve the amount of charge.

1 is an overall system diagram illustrating a plug-in hybrid vehicle to which a control device according to a first embodiment is applied. It is explanatory drawing explaining the EV possible charge amount used in Example 1. FIG. (a) is a perspective view which shows the battery control circuit used for the charger in Example 1, (b) is an enlarged perspective view which shows the transformer core mounted in FIG. 3 (a), (c) is FIG. 4 is a longitudinal sectional view of the transformer core shown in FIG. It is a flowchart which shows the flow of the circuit cooling process before charge performed with the vehicle controller of Example 1. FIG. It is a flowchart which shows the flow of the circuit cooling process during charge performed by the vehicle controller of Example 1. FIG. 4 is a time chart showing characteristics of a battery SOC, a traveling mode, an engine cooling unit driving state, and a transformer core temperature before and after charging from an external power source in the control device of the first embodiment.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the control apparatus of the plug-in hybrid vehicle of this invention is demonstrated based on Example 1 shown in drawing.

Example 1
First, the configuration of the control device for the plug-in hybrid vehicle of the first embodiment is described as “the overall system configuration of the plug-in hybrid vehicle”, “the detailed configuration of the transformer core”, “the circuit cooling processing configuration before charging”, “the circuit cooling during charging” The processing will be described separately.

[Overall system configuration of plug-in hybrid vehicle]
FIG. 1 is an overall system diagram illustrating a plug-in hybrid vehicle to which the control device of the first embodiment is applied. The overall system configuration of the plug-in hybrid vehicle according to the first embodiment will be described below with reference to FIG.

  The control device for the plug-in hybrid vehicle of the first embodiment is applied to the plug-in hybrid vehicle P-HEV shown in FIG. The plug-in hybrid vehicle P-HEV includes a drive motor 1 (motor) as a travel drive source, a chargeable / dischargeable battery 2 that stores electric power supplied to the drive motor 1, and the drive motor 1 or battery 2. A power generation device 3 (power generation means) for generating power for supplying power to the vehicle, and a vehicle controller 4 for controlling the operation system of the entire vehicle.

  The drive motor 1 is directly connected to the power transmission device 6 of the drive wheel 5 and is controlled by a motor control device 7 via an inverter 8 to provide power running state in which torque is generated and regenerative energy during deceleration. Rotation control is performed according to the vehicle state such as the regenerative state absorbed by the battery 2.

The battery 2 is charge / discharge controlled by the battery control device 9, and supplies power to the drive motor 1, power generated by the power generation device 3, power regenerated when the drive motor 1 is decelerated, and an outlet 11 of the charger 10. The charging control of the electric power from the external power supply (not shown) performed via is performed.
Here, the charger 10 is equipped with a charge control circuit 10 a that controls power from an external power source charged in the battery 2. The charge control circuit 10a generates heat by charging the battery 2 from an external power source.

  The power generation device 3 includes an engine 12 as a power generation drive source and a generator 13 that is driven by the engine 12 to generate power. The engine 12 controls the combustion injection amount, intake air amount, ignition timing, and the like by the engine control device 14. The generator 13 performs rotation control according to the power generation state and the power consumption state via the inverter 16 by the generator control device 15.

  The vehicle controller 4 manages the energy consumption of the entire vehicle and has an integrated control function for running the vehicle with the highest efficiency. The drive motor control system, battery control system, engine control system, and power generation described above Exchanges information with the machine control system. The vehicle controller 4 includes information from an accelerator opening sensor 101, a vehicle speed sensor 102, a motor rotation speed sensor 103, an engine rotation speed sensor 104, an outside air temperature sensor 105, a charger temperature sensor 106 (circuit temperature detection means), and the like. Enter. The charger temperature sensor 106 does not directly measure the temperature of the charger 10, but detects the ambient temperature (atmosphere temperature) of the charger 10, and the charge mounted on the charger 10 from the detected ambient temperature. The temperature of the control circuit 10a is estimated and used as a transformer core temperature described later.

In the vehicle controller 4, information obtained from each control system, driver operation input (accelerator opening), vehicle speed, drive motor rotation speed, engine rotation speed, outside air temperature, charge control mounted on the charger 10. The entire system is controlled based on various sensor information for detecting the temperature and the like of the circuit 10a.
That is, a signal for driving the driving motor 1 is output to the motor control device 7 in response to a request from the driver. In addition, the battery 2 reads the charge capacity of the battery 2 (hereinafter referred to as “battery SOC”) via the battery control device 9 and performs power generation so that the battery SOC is appropriate for the current driving state and future driving schedule. As described above, the engine 12 and the generator 13 are controlled via the engine control device 14 and the generator control device 15. Further, when charging the battery 2 from the external power source at the charging point, the battery 2 is charged with an appropriate amount of power by controlling the charger 10 while monitoring the state of the battery 2 via the battery control device 9. .

  Here, the plug-in hybrid vehicle P-HEV has an electric vehicle mode (hereinafter referred to as “EV mode”) and a hybrid vehicle mode (hereinafter referred to as “HEV mode”) as vehicle modes depending on the driving state of the engine 12. And).

The “EV mode” is a vehicle mode in which the engine 12 is stopped and power is not generated by the generator 13. In the EV mode, the drive motor 1 is driven by electric power supplied from the battery 2. Incidentally, the EV mode is selected when the battery SOC is greater than the engine start threshold SOC_ _ENG previously set.

The “HEV mode” is a vehicle mode in which the engine 12 is driven to generate power by the generator 13. In the HEV mode, the drive motor 1 is driven by the electric power generated by the generator 13. In the HEV mode, the battery 2 may be charged while driving the driving motor 1 with the generated power. Incidentally, the HEV mode is selected when the battery SOC is less than the engine start threshold SOC_ _ENG previously set.

And high voltage components, such as the drive motor 1, the generator 13, those inverters 8 and 16, and the charger 10, were equipped with the 1st radiator 17, the 1st cooling water pump 18, and the 1st radiator cooling fan 17a. Appropriate cooling is performed by the electrical component cooling unit 24.
Similarly, the engine 12 is appropriately cooled by an engine cooling unit 25 (engine cooling means) including a second radiator 19, a second cooling water pump 20, and a second radiator cooling fan 19a. In the engine cooling unit 25, circulating cooling water is introduced into the heater unit 21, and an electric heater 22 is assembled to the heater unit 21, so that both the heat energy of the engine cooling water and the heat energy of the electric heater 22 are used. The room heating can be used properly.

Further, the vehicle controller 4 exchanges information with the navigation system 23 mounted on the vehicle, and acquires information on a charging point that is ahead in the vehicle traveling direction. That is, the navigation system 23 has map information in which charging points are set in advance. If a scheduled travel route is set, a charging point on this planned route is detected and input to the vehicle controller 4. In addition, when the scheduled travel route is not set, a charging point existing within a predetermined range from the current point is detected and input to the vehicle controller 4.
The “charging point” is a so-called rapid charging spot, and is a place where the battery 2 can be rapidly charged (high voltage charging) from an external power source.

  Furthermore, in the control device for the plug-in hybrid vehicle of the first embodiment, in preparation for charging from the external power source, pre-charging circuit cooling control is performed to suppress the temperature rise of the charging control circuit 10a during traveling. Therefore, the vehicle controller 4 includes a charging point setting unit 41, a charging capacity monitoring unit 42, a charging capacity determination unit 43, and an engine control unit 44.

The charging point setting unit 41 is an arithmetic circuit that acquires charging point information from the navigation system 23 and sets a target charging point based on the acquired charging point information. Here, the “target charging point” is a charging point where charging from an external power source is actually performed.
In the charging point setting unit 41, when there is one charging point based on the acquired charging point information, this charging point is set as the target charging point. When there are a plurality of charging points based on the acquired charging information, the charging point set by an arbitrary means is set as the target charging point. That is, when the user has set a target charging point in advance, when setting an arbitrary charging point as a recommended point, when determining the need for charging based on the battery SOC and setting an optimal charging point, etc. is there.

The charging capacity monitoring unit 42 is an arithmetic circuit that monitors the battery SOC when the distance from the current vehicle point to the target charging point reaches a predetermined SOC monitoring start distance set in advance. Here, the “SOC monitoring start distance” is an arbitrary distance that can secure a cooling period in which cooling is performed until it can be determined that the charging control circuit 10a of the charger 10 has sufficiently cooled before reaching the target charging point. Yes, for example, 5 km or 10 km is set according to the power generation capacity of the battery SOC and the power generation device 3.
A point that is separated from the target charging point by the “SOC monitoring start distance” is referred to as an “SOC monitoring start point”. In other words, when the host vehicle reaches the “SOC monitoring start point” while the host vehicle is traveling toward the “target charging point”, the charging capacity monitoring unit 42 starts monitoring the battery SOC.

The charge capacity determination unit 43 is an arithmetic circuit that determines whether or not the battery SOC has reached an EV chargeable amount after the vehicle has reached the SOC monitoring start distance. Here, the “EV chargeable amount” is a charge capacity that enables selection of the EV mode in which the engine 12 is stopped until the target charge point is reached from the current vehicle point. The EV chargeable amount is set based on the battery SOC decrease acceleration in the EV mode and the target battery SOC when the target charging point is reached.
That is, as shown in FIG. 2, first, a target value (target battery SOC) A of the battery SOC when the target charging point is reached is set. Next, assuming that the battery SOC becomes the target battery SOC (A) when the target charging point is reached, the change in the battery SOC when the vehicle is traveling in the EV mode with the inclination θ determined by the battery SOC decreasing acceleration in the EV mode. Is estimated as shown by the solid line. This estimated value becomes the “EV possible charge amount”.
That is, for example, when the vehicle is battery SOC is SOCα at the x position when, if travel the remaining distance to the target charging location in the EV mode, the battery SOC is running limit threshold SOC_ _LOW before reaching the target charging site And the EV mode cannot be run. On the other hand, if the vehicle is y position is also the battery SOC is a SOCarufa, even traveling the remaining distance to the target charging location in the EV mode, the target charge point before the battery SOC reaches a travel limit threshold SOC_ _LOW Can reach.

If the battery SOC is equal to or higher than the EV chargeable amount, the engine control unit 44 stops the engine 12 until the target charging point is reached, and if the battery SOC is equal to or lower than the EV chargeable amount, the engine control unit 44 drives the engine 12. Circuit.
When the engine 12 is stopped by the engine control unit 44, the vehicle mode becomes the EV mode. On the other hand, when the engine 12 is driven by the engine control unit 44, power is generated by the generator 13, and charging control for the battery 2 is performed.

[Detailed configuration of transformer core]
FIG. 3A is a perspective view showing a charge control circuit mounted on the charger in the first embodiment, and FIG. 3B is an enlarged perspective view showing a transformer core provided in the charge control circuit of FIG. It is a figure and (c) is a longitudinal cross-sectional view of the transformer core shown in FIG.3 (b). Hereinafter, the detailed configuration of the transformer core according to the first embodiment will be described with reference to FIG.

  The charging control circuit 10a mounted on the charger 10 of the first embodiment has a pair of transformer cores 26 provided on the base 10b as shown in FIG. The transformer core 26 is a control circuit component that transforms the voltage of power regenerated when the drive motor 1 is decelerated or the voltage of power supplied from an external power source into a chargeable voltage.

  As shown in FIGS. 3B and 3C, the transformer core 26 includes an insulating case 26a, a core (iron core) 26b housed in the case 26a, and an insulator 26c on the core 26b. A wound coil 26d and an aluminum plate 26e that protects the coil 26d are provided.

  The transformer core 26 generates heat when a current flows during charging from an external power source, but has a characteristic that the voltage conversion efficiency decreases as the temperature rises. That is, as the transformer core temperature increases, the charge amount of the battery 2 per unit time decreases, and the charge time until the required charge amount is reached increases.

Further, the charger 10 is disposed in a region that is affected by heat from the engine 12. Here, the “region affected by the heat from the engine 12” is a region where the temperature is raised by the heat generated by the engine 12.
That is, the ambient temperature around the charger 10 is increased by the heat generated by driving the engine 12, and as a result, the temperature of the charging control circuit 10 a of the charger 10 including the transformer core 26 is increased.

Here, the drive motor 1, the engine 12 and the generator 13 of the power generation device 3, and the charger 10 are arranged in a power unit room that is partitioned in the front part of the vehicle and are arranged close to each other.
Further, the first radiator cooling fan 17a of the electric component cooling unit 24 and the second radiator cooling fan 19a of the engine cooling unit 25 are both disposed in the power unit room. The first radiator cooling fan 17a is driven to blow air to the first radiator 17 and stirs the air in the power unit room. The second radiator cooling fan 19a is driven to blow air to the second radiator 19 and stirs the air in the power unit room.

[Circuit processing configuration before charging]
FIG. 4 is a flowchart illustrating a flow of pre-charging circuit cooling processing executed by the vehicle controller of the first embodiment. Hereinafter, the pre-charging circuit cooling processing configuration of the first embodiment will be described with reference to FIG. The pre-charging circuit cooling process starts when the vehicle start switch is turned on.

  In step S1, charging point information is acquired from the navigation system 23, a target charging point is set based on the acquired charging point information, and the process proceeds to step S2.

In step S2, following the setting of the target charging point in step S1, the distance from the vehicle position (current point) to the target charging point set in step S1 is calculated, and the process proceeds to step S3.
This distance calculation to the target charging point is calculated based on the map information acquired from the navigation system 23 and the radio signal from the GPS satellite that specifies the position of the host vehicle.

  In step S3, following the calculation of the distance to the target charging point in step S2, whether or not the calculated distance is shorter than the arbitrarily set SOC monitoring start distance, that is, the host vehicle reaches the SOC monitoring start point. Determine whether or not. If YES (calculation distance ≦ SOC monitoring start distance), the process proceeds to step S4. If NO (calculation distance> SOC monitoring start distance), it is determined that the host vehicle has not reached the SOC monitoring start point, and the process returns to step S2.

In step S4, following the determination that the calculation distance ≦ SOC monitoring start distance in step S3, the temperature of the transformer core 26 is detected, and the process proceeds to step S5.
Here, the temperature of the transformer core 26 is estimated based on the temperature around the charger 10 detected by the charger temperature sensor 106, here, the temperature in the power unit room.

In step S5, following the detection of the transformer core temperature in step S4, it is determined whether or not the detected transformer core temperature is equal to or higher than an arbitrarily set first threshold value T1. In the case of YES (transformer core temperature ≧ first threshold T1), if charging from the external power supply is started immediately, the transformer core 26 reaches the charge limit temperature during charging and the process proceeds to step S7. If NO (transformer core temperature <first threshold value T1), the process proceeds to step S6.
Here, the “first threshold value T1” is a temperature at which it can be determined that the temperature of the transformer core 26 does not reach the charge limit temperature (for example, 120 ° C.) during charging from the external power supply, and the transformer core 26 accompanying the charging operation. Set based on the rising temperature. Note that the temperature rise of the transformer core 26 due to the operation during charging is estimated based on the battery SOC that can be charged when the battery 2 is assumed to be fully charged and the specification (maximum current) of the charging facility.

  In step S6, following the determination that the transformer core temperature <the first threshold value T1 in step S5, the transformer core 26 is sufficiently cooled, or the temperature of the transformer core 26 is set to the charge limit temperature during charging with a small amount of charge. Therefore, it is determined whether or not the target charging point has been reached, assuming that charging from the external power source can be started immediately. If yes (arrival), go to end. If NO (not arrived), the process returns to step S5.

In step S7, following the determination that the transformer core temperature ≧ first threshold value T1 in step S5, the battery SOC, which is the charge capacity remaining in the current battery 2, is detected, and the process proceeds to step S8.
Here, the battery SOC is detected based on information from the battery control system.

In step S8, following the detection of the battery SOC in step S7, it is determined whether or not the battery SOC is equal to or greater than a preset EV chargeable amount. If YES (battery SOC ≧ EV possible charge amount), the process proceeds to step S11. If NO (battery SOC <EV chargeable amount), the process proceeds to step S9.
Here, “EV chargeable amount” is set in advance as shown in FIG.

In step S9, following the determination that battery SOC <EV possible charge amount in step S8, the engine 12 is driven, and the process proceeds to step S10.
Note that “drive the engine 12” in step S9 means that if the engine 12 has already been driven, the engine drive state is continued, and if the engine 12 has stopped, engine start control is performed. is there.

In step S10, following the engine driving in step S9, the generator 13 is driven using the driving force of the engine 12 to charge the battery 2, and the process returns to step S5.
The generated power (engine driving force) at this time is set to the maximum power. As a result, the battery SOC rises, and the EV mode can be reliably selected before reaching the target power generation point.

In step S11, following the determination that battery SOC ≧ EV possible charge amount in step S8, the engine 12 is assumed to be able to travel with the EV mode in which the engine 12 is stopped until the target charging point is reached. Is stopped, and the process proceeds to step S12.
Note that “stop the engine 12” in step S11 means that if the engine 12 has already stopped, the engine stop state is continued, and if the engine 12 is driven, engine stop control is performed. is there.

In step S12, following the engine stop in step S11, engine cooling control is performed, and the process proceeds to step S13.
Here, “engine cooling control” refers to driving the second cooling water pump 20 and the second radiator cooling fan 19a of the engine cooling unit 25 to perform forced cooling of the engine 12. Normally, when the engine 12 is stopped, the second cooling water pump 20 and the second radiator cooling fan 19a are stopped unless the engine temperature is very high. However, in this step S12, in order to suppress the thermal influence from the engine 12, an engine cooling process is performed in order to reliably and quickly cool the engine.
This engine cooling process may be performed until the vehicle arrives at the target charging point, and ends when the temperature of the engine cooling water converges to about room temperature (the second cooling water pump 20 and the second radiator cooling fan 19a are turned on). Stop).

  In step S13, following execution of engine cooling control in step S12, it is determined whether or not the vehicle has arrived at the target charging point. If yes (arrival), go to end. If NO (not arrived), the process returns to step S11.

[Circuit cooling configuration during charging]
FIG. 5 is a flowchart showing a flow of the charging circuit cooling process executed by the vehicle controller of the first embodiment. Hereinafter, the circuit cooling process configuration during charging according to the first embodiment will be described with reference to FIG. The circuit cooling process during charging starts when the outlet 11 is connected to an external power source and charging of the battery 2 from the external power source starts.

In step S20, the temperature of the transformer core 26 is detected, and the process proceeds to step S21.
Here, the temperature of the transformer core 26 is estimated based on the temperature around the charger 10 detected by the charger temperature sensor 106, here, the temperature in the power unit room, as in step S4 in the pre-charging circuit cooling process. To do.

In step S21, following the detection of the transformer core temperature in step S20, it is determined whether or not the detected transformer core temperature is equal to or higher than a second threshold value T2 set arbitrarily.
If YES (transformer core temperature ≧ second threshold T2), the process proceeds to step S22. If NO (transformer core temperature <second threshold value T2), the process proceeds to step S23.
Here, the “second threshold value T2” is a temperature at which it is determined that the conversion efficiency when the voltage of the power supplied from the external power supply by the transformer core 26 is transformed into a chargeable voltage has decreased, and the voltage conversion efficiency It is arbitrarily set based on.

  In step S22, following the determination that transformer core temperature ≧ second threshold value T2 in step S21, the second radiator cooling fan 19a is driven to stir the air in the power unit room, and the process proceeds to step S23.

In step S23, following the driving of the second radiator cooling fan 19a in step S22, it is determined whether or not charging from the external power source is completed. If YES (charge complete), go to end. At this time, if the second radiator cooling fan 19a is driven, it is stopped. If NO (incomplete charging), the process proceeds to step S24.
Here, the completion of charging is determined when the battery SOC reaches a target value, when the rate of increase of the battery SOC becomes equal to or less than a predetermined value (that is, when the battery SOC no longer increases above a certain value), or the like. .

  In step S24, following the determination that charging is not completed in step S23, the temperature of the transformer core 26 is detected again, and the process proceeds to step S25.

In step S25, following the detection of the transformer core temperature in step S24, it is determined whether or not the detected transformer core temperature is equal to or higher than a preset charge limit temperature. If YES (transformer core temperature ≧ charge limit temperature), the transformer core 26 becomes high temperature and charging cannot be continued, and charging to the battery 2 is interrupted and the process proceeds to the end. At this time, if the second radiator cooling fan 19a is driven, it is stopped. If NO (transformer core temperature <charge limit temperature), the process returns to step S21.
Here, the “charge limit temperature” is an upper limit value of the temperature of the transformer core 26 that generates heat during charging from an external power supply, and is a temperature at which charging cannot be performed (for example, 120 ° C.).

Next, the operation will be described.
First, “pre-charge control and its problems in the control device of the comparative example” will be described, and subsequently, the actions in the control device of the plug-in hybrid vehicle of the first embodiment are “pre-charge circuit cooling action” and “during charging” The description will be divided into “circuit cooling action”.

[Control before charging in control device of comparative example and its problems]
FIG. 6 is a time chart showing characteristics of the battery SOC, the vehicle mode, the second radiator cooling fan, and the transformer core temperature before and after charging from the external power supply in the control device of the first embodiment. In FIG. 6, each characteristic of the control device for the plug-in hybrid vehicle of the comparative example is indicated by a broken line. Hereinafter, based on FIG. 6, the pre-charge control and its problem in the control device of the comparative example will be described.

Usually, the plug-in hybrid vehicle P-HEV, while the battery SOC during running is above the engine start threshold SOC_ _ENG is driving motor 1 selects the EV mode in which the vehicle travels only by power supplied from the battery 2 Run. At this time, the engine 12 is stopped and power generation by the generator 13 is not performed.

Then, when the battery SOC is lower than the engine start threshold SOC_ _ENG, power generation by the generator 13 to start the engine 12, selects the HEV mode in which the vehicle travels by driving the drive motor 1 by power generated from the power generator 3 . At this time, the generated power of the engine 12 fluctuates according to the traveling load and covers the required motor torque.
However, if the generated power of the engine 12 is controlled in accordance with the traveling load, the engine 12 often becomes an operating point outside the optimum fuel consumption region, and the fuel consumption increases. Therefore, the battery SOC is (there is a margin to the running limit threshold SOC_ _LOW) relatively large, when the charging point is found to be short, to drive the engine 12 at the optimum fuel consumption region. Then, the supply power from the battery 2 covers the amount of generated power that is insufficient with respect to the required motor torque.

That is, as shown in FIG. 6, when the battery SOC is greater than the engine start threshold SOC_ _ENG is, EV mode to stop the engine 12 is selected, by driving the drive motor 1 in the electric power supplied from the battery 2 travel To do. Therefore, the battery SOC that is the charging capacity of the battery 2 decreases with time. Further, since the engine 12 is stopped, both the second cooling water pump 20 and the second radiator cooling fan 19a of the engine cooling unit 25 are also stopped.
Further, since the engine 12 is stopped, the temperature of the engine 12 does not rise, and the thermal effect of the engine 12 does not occur. Therefore, even if the charger 10 is disposed in a region that is affected by heat from the engine 12, the temperature of the transformer core 26 is maintained at substantially the same level as the atmospheric temperature.

At time t _1, When the battery SOC is less than the engine start threshold SOC_ _ENG, it switched from the EV mode in which the vehicle travels to stop the engine 12, and to the HEV mode in which the vehicle travels while generating electric power by driving the engine 12. At this time, the generated power of the engine 12 is set to such an extent that the required motor torque can be covered, and the battery SOC hardly decreases.

At time t _2, the remaining distance to the target charging location is shorter than SOC monitoring start distance, the vehicle is when it reaches the SOC monitoring start point, charging site is determined to close. Then, the generated power is controlled so that the operating point of the engine 12 is in the optimum fuel efficiency region. As a result, after time t ₂ , the driving motor 1 is driven by making up for the shortage of the required motor torque with the power supplied from the battery 2. As a result, the battery SOC starts to decrease.
At this time, since the engine 12 is driven and the generator 13 generates electric power, the decrease acceleration of the battery SOC becomes a value smaller than that in the EV mode.

On the other hand, as the engine 12 is driven, the second cooling water pump 20 and the second radiator cooling fan 19a of the engine cooling unit 25 are driven to perform engine cooling.
However, even if the engine cooling is performed by the engine cooling unit 25, the engine temperature rises, so that a thermal effect from the engine 12 occurs and the temperature of the transformer core 26 also rises.

At time t _6, when it reaches the target charge point, it stops to stop the driving motor 1 and the engine 12. Accordingly, the second cooling water pump 20 and the second radiator cooling fan 19a of the engine cooling unit 25 are also stopped. Then, the outlet 11 is connected to an external power source, and charging from the external power source is started. The charging from the external power source is so-called rapid charging.

When charging from the external power source is started, a current flows through the transformer core 26 of the charge control circuit 10a to transform the voltage of the power supplied from the external power source into a chargeable voltage, and the transformer core 26 generates heat. To do. That is, the transformer core temperature increases with charging. Further, the battery SOC also rises due to charging.
In this case, the transformer core temperature, because that is already high in charging start time (time t ₆ time), the voltage conversion efficiency of the transformer core 26 is worse than if the transformer core temperature is low. Therefore, the amount of charge per unit time is smaller than when the transformer core temperature is low.

Further, at time t _8, the transformer core temperature reaches the charging limit temperature T_ _MAX, charging from an external power supply is forcibly prohibited. Thereby, the increase in the battery SOC is stopped.

Thus, in the control apparatus of a plug-in hybrid vehicle in the comparative example, until it reaches the charging location, because the battery SOC is less than the engine start threshold SOC_ _ENG, a HEV mode in which the engine 12 is driven. Therefore, the thermal effect generated by the engine 12 is driven, the transformer core temperature rises, the charge start time from an external power source (time t ₆ time) transformer core 26 is already heated.
As a result, the voltage conversion efficiency of the transformer core 26 is relatively low, and the charge capacity per unit time is reduced as compared with the case where the transformer core temperature is low. Therefore, the charging time increases.
Further, a transformer core temperature short time from the charging start will reach the charging limit temperature T_ _MAX, charging is forcibly prohibited. Therefore, a sufficient charging time cannot be secured and the battery SOC cannot be sufficiently recovered.

  If the transformer core temperature decreases, charging from the external power supply can be resumed. However, in order to do so, it is necessary to wait for the transformer core temperature to decrease, and in order to sufficiently recover the battery SOC. This waiting time is necessary. As a result, the charging time increases.

[Circuit cooling before charging]
Next, the pre-charging circuit cooling operation of the first embodiment will be described with reference to FIG.

  In the control device for the plug-in hybrid vehicle of the first embodiment, when the vehicle drive switch is turned on, the pre-charging circuit cooling process shown in FIG. 4 is executed. That is, when the target charging point is set in step S1, the process proceeds to step S2 to calculate the distance from the current point to the target charging point. Then, the process proceeds to step S3, and it is determined whether or not the remaining distance to the target charging point is shorter than the SOC monitoring start distance. If the vehicle has not reached the SOC monitoring start point, the procedure from step S2 to step S3 is repeated.

Then, before the vehicle reaches the SOC monitoring start point, at time t ₁ point shown in FIG. 6, when the battery SOC is lower than the engine start threshold SOC_ _ENG, from EV mode to travel to stop the engine 12, the engine 12 is switched to the HEV mode in which the vehicle travels while generating electric power. At this time, the generated power of the engine 12 is set to such an extent that the required motor torque can be covered, and the battery SOC hardly decreases.
On the other hand, when the engine 12 is driven, the transformer core 26 is affected by heat from the engine 12 and the temperature rises.

In the time t ₁ earlier, since it is EV mode to stop the engine 12, the battery SOC decreases with time. Further, since the engine 12 is stopped, both the second cooling water pump 20 and the second radiator cooling fan 19a of the engine cooling unit 25 are also stopped.
Further, since the engine 12 is stopped, the temperature of the engine 12 does not rise, and the thermal effect of the engine 12 does not occur. Therefore, although the charger 10 is disposed in a region that is affected by heat from the engine 12, the temperature of the transformer core 26 is maintained at approximately the same level as the atmospheric temperature.

Then, at time t ₂ time, when the remaining distance to the target charging location is shorter than SOC monitoring start distance, the vehicle reaches the SOC monitoring start point, the process proceeds to step S4 → step S5, the transformer core temperature first It is determined whether or not it is equal to or greater than one threshold T1. The time t ₂ time, since a transformer core temperature <first threshold value T1, the process proceeds to step S6, it is determined whether or not arrived at the target charging site. In the time t ₂ point in time, because it does not arrive at the target charge point, repeat the step S4 → step S5.

Further, at time t _2, the host vehicle that has reached the SOC monitoring start point, charging site is determined to close, generated power is controlled so that the operating point of the engine 12 becomes optimum fuel consumption region. As a result, the shortage of the required motor torque is compensated for by the power supplied from the battery 2, so that the battery SOC begins to decrease.

At time t _3, When the transformer core temperature reaches the first threshold value T1, the process proceeds to step S7 → step S8, to detect the battery SOC, the battery SOC is judged whether or not EV chargeable amount or more . In time t ₃ point, since a battery SOC <EV can be charged amount, the process proceeds to step S9 → step S10, the battery 2 is charged engine 12 is driven.
Here, the engine 12 from the time t ₁ since is driven, the engine driving state is maintained. Meanwhile, in this time t ₃ before, as the operating point of the engine 12 becomes optimum fuel consumption area, generated power is controlled, the battery SOC is lower. Therefore, in this time t ₃ after the power generation power of the engine 12 is set to the maximum power, while catering the required motor torque of the drive motor 1 at a power generated from the power generator 3, the battery SOC and charging the battery 2 Raise.

Then, at time t _4, When the battery SOC reaches EV chargeable amount, the process proceeds to step S8 → step S11, stops the engine 12 to drive the drive motor 1 only electric power supplied from the battery 2 to run The EV mode to be selected is selected. Furthermore, it progresses to step S12 and engine cooling control is implemented and the engine 12 has stopped, but the 2nd cooling water pump 20 and the 2nd radiator cooling fan 19a of the engine cooling unit 25 drive. Thereby, cooling of the engine 12 is promoted.

Then, the engine 12 is stopped, and further, engine cooling is promoted by the engine cooling unit 25, so that the thermal influence from the engine 12 is rapidly alleviated and the transformer core temperature is lowered.
Further, the battery SOC is rapidly reduced as compared with the comparative example that runs in the HEV mode because the EV mode is selected. In Example 1, than for driving a second cooling water pump 20 and the second radiator cooling fan 19a by using the electric power supplied from the battery 2, EV mode in which these stops (time t ₁ earlier) However, the decrease acceleration of the battery SOC is large.

At time t _5, when the transformer core temperature is becoming close to the ambient temperature, that is, if the difference between the transformer core temperature and the atmospheric temperature is equal to or less than a predetermined value, as the engine 12 is sufficiently cooled, the second cooling water The pump 20 and the second radiator cooling fan 19a are stopped.
As a result, the decrease in acceleration of the battery SOC, the time t ₁ at the same level as during the previous EV mode.

At time t _6, when it reaches the target charge point, it stops to stop the drive motor 1. Thereby, it progresses to step S12-> step S13-> end, and the circuit cooling process before charge shown in FIG. 4 is complete | finished. Then, the outlet 11 is connected to an external power source, and charging from the external power source is started.

As described above, by selecting the EV mode in which the engine 12 is stopped and traveling before reaching the target charging point, it is possible to prevent the temperature of the transformer core 26 from being affected by the heat from the engine 12. Therefore, in the charging start time (time t ₆ time), it is possible to suppress the transformer core temperature to approximately the same as the atmospheric temperature.

Also, before reaching the target charge point, when the battery SOC has selected the EV mode even below the engine start threshold SOC_ _ENG, i.e. at time t ₄ when the battery SOC has reached the EV chargeable amount. As described above, since it is determined that the battery SOC is secured to the extent that it can travel in the EV mode up to the target charging point and is in the EV mode, the battery SOC travels before reaching the target charging point. not reach the critical threshold value SOC_ _LOW, it may continue to stop the engine 12 to the target charging location. As a result, the transformer core 26 can be reliably prevented from being affected by the heat from the engine 12 immediately before charging, and the temperature rise of the transformer core 26 can be suppressed.

Further, in the first embodiment, when the transformer core temperature becomes equal to or higher than the first threshold T1, the battery SOC is compared with the EV chargeable amount. If the battery SOC has reached the EV chargeable amount, the engine 12 is stopped. Select EV mode. In other words, the transformer core temperature, if the temperature does not reach the charging limit temperature T_ _MAX during charging, not forcibly selecting the EV mode.
Therefore, unnecessary engine stop can be prevented and charging from the external power source can be prevented from being unnecessarily increased.

Further, in Example 1, when the battery SOC has selected the EV mode by reaching the EV chargeable amount, i.e. time t ₄ later, although the engine is stopped 12, the engine cooling unit 25 2 Cooling water pump 20 and the 2nd radiator cooling fan 19a drive, and engine cooling is performed even after an engine stop.
Therefore, cooling of the engine 12 in the EV mode is promoted, and the transformer core temperature affected by the heat from the engine 12 can be quickly reduced.

  Moreover, in the first embodiment, when the difference between the transformer core temperature and the atmospheric temperature becomes equal to or less than a predetermined value, the driving of the second cooling water pump 20 and the second radiator cooling fan 19a is stopped. Thereby, useless engine cooling can be suppressed and reduction of battery SOC can be suppressed.

[Circuit cooling during charging]
Next, the circuit cooling operation during charging according to the first embodiment will be described with reference to FIG.

At time t ₆ shown in FIG. 6, when charging from an external power source is started, in order to transform the power of the voltage supplied from the external power source to the chargeable voltage, the current transformer core 26 of the charge control circuit 10a flow The transformer core 26 generates heat. That is, the transformer core temperature increases with charging. Moreover, the battery SOC also rises by charging.
On the other hand, the circuit cooling process during charging shown in FIG. 5 is executed with the start of charging, and the process proceeds from step S20 to step S21 to determine whether or not the transformer core temperature is equal to or higher than the second threshold value T2.

Here, the temperature of the transformer core 26, and have the same level as the atmospheric temperature in the charging start time (time t ₆ time). Therefore, the process proceeds to step S23, it is determined whether the charging is completed, the process proceeds from step S24 to step S25, and the process of returning to step S21 again because the transformer core temperature is low is repeated.
Also, since the transformer core temperature is low, the voltage conversion efficiency in the transformer core 26 is better than in the comparative example, and the amount of charge per unit time is higher than when the transformer core temperature is high (comparative example). Therefore, if the same amount of charge as when the transformer core temperature is high (comparative example) is charged, the charging time can be shortened and the total travel time to the final destination including this charging time can be shortened. Can do.

Then, at time t _7, the transformer core temperature reaches the second threshold value T2, the routine proceeds to step S21, and drives the second radiator cooling fan 19a. Thereby, the air in the power unit room where the charger 10 is arranged is agitated, and the temperature rise of the transformer core 26 is suppressed.

At time t _9, the transformer core temperature reaches the charging limit temperature T_ _MAX, charging from an external power supply is forcibly prohibited, the process proceeds to step S22 → step S23 → step S24 → step S25 → end, during the charging The circuit cooling process ends.
Thus, although the charge and transformer core temperature reaches the charging limit temperature T_ _MAX is stopped, since the transformer core temperature is sufficiently low at the charging start time (time t ₆ time), to ensure a sufficient charging time Can do. Thereby, the amount of charge is increased as compared with the comparative example, and the battery SOC can be sufficiently increased.
And the period (distance) which can drive | work in EV mode after charge can be expanded, and the improvement of a fuel consumption can be aimed at.

  In the first embodiment, when the transformer core temperature exceeds the second threshold value T2 during charging, the second radiator cooling fan 19a is driven to agitate the air in the power unit room. As a result, an increase in transformer core temperature can be suppressed, a decrease in voltage conversion efficiency can be suppressed, and the amount of charge can be further increased.

Next, the effect will be described.
In the control device for the plug-in hybrid vehicle of the first embodiment, the following effects can be obtained.

(1) A motor (driving motor 1) as a travel drive source;
A battery 2 that stores electric power to be supplied to the motor (driving motor 1) and that can be charged from an external power source;
Power generation means (power generation device 3) for charging the battery 2;
An engine 12 as a power generation drive source for driving the power generation means (power generation device 3);
In a plug-in hybrid vehicle P-HEV provided with a charge control circuit 10a that controls electric power charged in the battery 2 and generates heat when the battery 2 is charged.
The charge control circuit 10a is disposed in a region that is affected by heat from the engine 12,
A charging point setting unit 41 for setting a charging point (target charging point) at which the battery 2 can be charged from the external power source;
When the distance to the charging point (target charging point) reaches a predetermined SOC monitoring start distance that can secure a cooling period for cooling the charging control circuit 10a before arrival of the charging point (target charging point), A charge capacity monitoring unit 42 for monitoring the charge capacity (battery SOC) of the battery 2;
After reaching the SOC monitoring start distance, the EV is an amount that can be set in the EV mode in which the engine 12 is stopped until the charging capacity (battery SOC) of the battery 2 reaches the charging point (target charging point). A charge capacity determination unit 43 for determining whether or not a possible charge amount has been reached;
If the charge capacity (battery SOC) of the battery 2 is equal to or greater than the EV chargeable amount, the EV mode is set until the charge point (target charge point) is reached, and the charge capacity (battery SOC) of the battery 2 is An engine control unit 44 that drives the power generation means (power generation device 3) by driving the engine 12 if it is equal to or less than the EV chargeable amount;
It was set as the structure provided with.
As a result, it is possible to suppress an increase in the charging time when charging the battery 2 from the external power source and to improve the charge amount.

(2) circuit temperature detection means (charger temperature sensor 106) for detecting the temperature of the charge control circuit 10a;
When the temperature of the charge control circuit 10a is equal to or higher than a predetermined value (first threshold value T1) that is arbitrarily set, the engine control unit 44 has a charge capacity (battery SOC) of the battery 2 equal to or higher than the EV possible charge amount. If so, the EV mode is set until the charging point (target charging point) is reached.
As a result, in addition to the effect of (1), it is possible to prevent an unnecessary engine stop and prevent the charging from the external power source from being increased unnecessarily.

(3) provided with an engine cooling means (engine cooling unit 25) for cooling the engine 12,
The engine cooling means (engine cooling unit 25) is configured to cool the engine 12 while traveling in the EV mode until reaching the charging point (target charging point).
Thereby, in addition to the effect of (1) or (2), the cooling of the engine 12 in the EV mode can be promoted, and the temperature of the charge control circuit 10a affected by the heat from the engine 12 can be quickly reduced. .

(4) comprising circuit temperature detection means (charger temperature sensor 106) for detecting the temperature of the charging control circuit 10a;
The engine cooling means (engine cooling unit 25) is configured to charge the battery 2 from the external power source when the temperature of the charging control circuit 10a is equal to or higher than a predetermined value (second threshold value T2) set in advance. The engine 12 is cooled.
Thereby, in addition to the effect of (3), the temperature rise of the charge control circuit 10a can be suppressed during charging, the decrease in voltage conversion efficiency in the charge control circuit 10a is suppressed, and the amount of charge is further increased. be able to.

  As mentioned above, although the control apparatus of the plug-in hybrid vehicle of this invention was demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, Each claim of a claim is a claim. Design changes and additions are allowed without departing from the gist of the invention.

  In the first embodiment, the temperature around the charger 10 (atmosphere temperature) is detected as the temperature of the transformer core 26 provided in the charge control circuit 10a, and the charge control circuit mounted on the charger 10 from the detected ambient temperature. An example is shown in which the temperature of 10a is estimated to be the transformer core temperature. However, the temperature of the charge control circuit 10a (transformer core 26) may be directly measured, or the temperature of the charge control circuit 10a may be estimated from the case temperature in which the charge control circuit 10a is housed. Furthermore, the temperature in the power unit room may be estimated from the engine coolant temperature, and the temperature of the charging control circuit 10a may be estimated from the estimated room temperature.

  In the first embodiment, the “EV possible charge amount” is set based on the battery SOC at the target charging point and the decrease acceleration of the battery SOC in the EV mode, but is not limited thereto. For example, you may set based on road surface load, traffic congestion information, required charge amount, etc.

  In the first embodiment, the control device for the plug-in hybrid vehicle according to the present invention generates power from the power generation device 3 when the engine 12 drives the generator 13 and drives the drive motor 1 with this power to travel. Although the example applied to what is called a series type hybrid vehicle was shown, it is not restricted to this. The present invention may be applied to a parallel hybrid vehicle in which both the engine and the motor can be a driving source.

P-HEV plug-in hybrid vehicle 1 drive motor (motor)
2 Battery 3 Power generation device (power generation means)
4 Vehicle Controller 10 Charger 10a Charge Control Circuit 11 Outlet 12 Engine 13 Generator 17 First Radiator 17a First Radiator Cooling Fan 18 First Cooling Water Pump 19 Second Radiator 19a Second Radiator Cooling Fan 20 Second Cooling Water Pump 23 Navigation system 24 Electrical component cooling unit 25 Engine cooling unit (engine cooling means)
26 transformer core 106 charger temperature sensor (circuit temperature detection means)
41 Charging point setting unit 42 Charging capacity monitoring unit 43 Charging capacity judging unit 44 Engine control unit

Claims (4)

A motor as a travel drive source;
A battery capable of storing electric power to be supplied to the motor and capable of being charged from an external power source,
Power generation means for charging the battery;
An engine as a power generation drive source for driving the power generation means;
In a plug-in hybrid vehicle comprising a charge control circuit that controls power charged in the battery and generates heat when the battery is charged.
The charge control circuit is disposed in a region that is affected by heat from the engine,
A charging point setting unit for setting a charging point at which the battery can be charged from the external power source;
A cooling period in which the charging control circuit is cooled to a temperature at which the charging control circuit can determine that the charging control circuit does not reach the charging limit temperature during charging by the external power supply before arrival at the charging point, before reaching the charging point. When a predetermined SOC monitoring start distance that can be secured is reached, a charge capacity monitoring unit that monitors the charge capacity of the battery;
After reaching the SOC monitoring start distance, it is determined whether or not the charge capacity of the battery has reached an EV possible charge amount that is an amount that can be set in an EV mode in which the engine is stopped until the charge point is reached. A charging capacity determination unit to perform,
If the charge capacity of the battery is equal to or greater than the EV chargeable amount, the EV mode is set until the charging point is reached. If the battery charge capacity is equal to or less than the EV chargeable amount, the engine is driven. An engine control unit for driving the power generation means;
A control means for a plug-in hybrid vehicle, comprising: In the control apparatus of the plug-in hybrid described in Claim 1,
Circuit temperature detecting means for detecting the temperature of the charge control circuit;
When the temperature of the charge control circuit is equal to or higher than a predetermined value, and the charge capacity of the battery is equal to or higher than the EV chargeable amount, the engine control unit is configured to operate in the EV mode until the charge point is reached. A control device for a plug-in hybrid vehicle. In the control device for a plug-in hybrid vehicle according to claim 1 or 2,
An engine cooling means for cooling the engine;
The control device for a plug-in hybrid vehicle, wherein the engine cooling means cools the engine when traveling in the EV mode until the charging point is reached. In the control device for a plug-in hybrid vehicle according to claim 3,
Circuit temperature detecting means for detecting the temperature of the charge control circuit;
The engine cooling means cools the engine when the battery is charged from the external power source when the temperature of the charging control circuit is equal to or higher than a predetermined value set in advance. Control device.