JP2015003681A - Control device of plug-in hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend capacitor life while shortening standby time for starter starting when there is reverse transition from CS mode to CD mode.SOLUTION: A drive system includes a starter motor, a lateral engine, and a motor/generator. A power source system includes a high energy battery, a capacitor, and a hybrid control module which controls charging/discharging of the capacitor. In a control device of an FF plug-in hybrid vehicle which enables external charging with the high energy battery, a hybrid control module that performs engine start control, mode selection control, and capacitor charging/discharging control, when there is reverse transition from "CS mode" to "CD mode", a charging current is reduced as a capacitor temperature rises for re-charging the capacitor, to be ready for starter starting.

Description

  The present invention relates to a control device for a plug-in hybrid vehicle that includes a starter motor that uses a capacitor as a power source and that can externally charge a high-power battery.

  Conventionally, when the vehicle is not in use, the voltage of the power storage unit is always controlled to be between the predetermined lower limit voltage and the predetermined holding voltage, and if the vehicle recognizes the driver by the driver authentication means, the power storage unit is fully charged. A power storage device having a configuration is known (see, for example, Patent Document 1).

JP 2008-141855 A

  However, the conventional device is configured to fully charge the power storage unit when the driver is recognized. For this reason, when recharging is requested in accordance with the transition of the driving mode, if the power storage unit is recharged using a current that can be fully charged even though the power storage unit is hot, There is a problem that the temperature of the power storage unit rises due to heat generated by recharging with a large current, and deterioration of the power storage unit proceeds.

  The present invention has been made paying attention to the above problem, and when there is a reverse transition from the CS mode to the CD mode, the plug-in hybrid capable of extending the capacitor life while shortening the starter start waiting time. An object of the present invention is to provide a vehicle control device.

In order to achieve the above object, the present invention includes a starter motor, an engine, and a motor / generator in a drive system. The power supply system includes a high-power battery that is a power source of the motor / generator, a capacitor that is a power source of the starter motor, and capacitor charge / discharge control means that controls charge / discharge of the capacitor.
In the control device for a plug-in hybrid vehicle capable of externally charging the high-power battery, an engine start control means, a travel mode selection control means, and a capacitor temperature detection means are provided.
The engine start control means starts the engine by starter start or motor / generator start.
The travel mode selection control means selects a CD mode for starting the engine as a rule when the charge capacity of the high-power battery is equal to or greater than a threshold, and as a rule when the charge capacity of the high-power battery is less than the threshold. Select CS mode to start motor / generator.
The capacitor temperature detecting means detects the temperature of the capacitor.
When there is a reverse transition from the CS mode to the CD mode, the capacitor charge / discharge control means prepares for the starter start by reducing the charging current and recharging the capacitor as the capacitor temperature increases.

Therefore, when there is a reverse transition from the CS mode to the CD mode, the higher the capacitor temperature, the smaller the charging current and the capacitor is recharged to prepare for the starter start.
That is, as a general rule, during the selection of the CS mode in which the engine start is M / G start, it is not necessary to increase the capacitor voltage in preparation for starter start. On the other hand, when the CD mode is selected, it is necessary to prepare for the starter start, and therefore, recharging is performed when there is a reverse transition from the CS mode to the CD mode. At the time of this recharging, it is necessary to recharge with a large current in order to shorten the waiting time until the starter start is enabled. However, when the capacitor temperature is high, if the capacitor is recharged with a large current, deterioration of the capacitor due to heat generation proceeds.
On the other hand, the higher the capacitor temperature, the smaller the charging current and the recharging of the capacitor. When the capacitor temperature is low, the waiting time until starter start is shortened. Progress of deterioration due to is suppressed.
As a result, when there is a reverse transition from the CS mode to the CD mode, it is possible to extend the capacitor life while shortening the starter start waiting time.

1 is an overall system diagram illustrating an FF plug-in hybrid vehicle to which a control device according to a first embodiment is applied. It is a power supply circuit diagram which shows the power supply system structure centering on the starter power supply of FF plug-in hybrid vehicle to which the control apparatus of Example 1 was applied. It is a block diagram which shows the control system structure of FF plug-in hybrid vehicle to which the control apparatus of Example 1 was applied. It is a flowchart which shows the flow of the capacitor charging / discharging control process performed with the hybrid control module of Example 1. FIG.

  Hereinafter, the best mode for realizing a control device for a plug-in hybrid vehicle of the present invention will be described based on Example 1 shown in the drawings.

First, the configuration will be described.
The configuration of the FF plug-in hybrid vehicle (an example of a plug-in hybrid vehicle) to which the control device of the first embodiment is applied is “drive system configuration”, “power supply system configuration”, “control system configuration”, “capacitor charge / discharge control”. The detailed configuration will be described.

[Drive system configuration]
FIG. 1 shows the entire FF plug-in hybrid vehicle. Hereinafter, the drive system configuration of the FF plug-in hybrid vehicle will be described with reference to FIG.

  As shown in FIG. 1, the drive system includes a starter motor 1 (abbreviated as “M”), a horizontal engine 2 (abbreviated as “ICE”), a first clutch 3 (abbreviated as “CL1”), and a motor / generator. 4 (abbreviation “M / G”), a second clutch 5 (abbreviation “CL2”), and a belt type continuously variable transmission 6 (abbreviation “CVT”). The output shaft of the belt type continuously variable transmission 6 is drivingly connected to the left and right front wheels 10R and 10L via a final reduction gear train 7, a differential gear 8, and left and right drive shafts 9R and 9L. The left and right rear wheels 11R and 11L are driven wheels.

  The starter motor 1 is a cranking motor that has a gear that meshes with an engine starting gear provided on a crankshaft of the horizontally placed engine 2 and that uses a capacitor 23 (described later) as a power source to rotationally drive the crankshaft when the engine is started.

  The horizontal engine 2 is an engine disposed in the front room with the crankshaft direction as the vehicle width direction, and includes an electric water pump 12 and a crankshaft rotation sensor 13 that detects reverse rotation of the horizontal engine 2.

  The first clutch 3 is a hydraulic multi-plate friction clutch that is interposed between the horizontally mounted engine 2 and the motor / generator 4, and is fully engaged / slip engaged / released by the first clutch oil pressure. The

  The motor / generator 4 is a three-phase AC permanent magnet type synchronous motor connected to the transverse engine 2 through a first clutch 3. The motor / generator 4 uses a high-power battery 21 described later as a power source, and an inverter 26 that converts direct current into three-phase alternating current during power running and converts three-phase alternating current into direct current during regeneration is connected to the stator coil. Connected through.

  The second clutch 5 is a wet-type multi-plate friction clutch by hydraulic operation that is interposed between the motor / generator 4 and the left and right front wheels 10R and 10L that are driving wheels. Slip fastening / release is controlled. The second clutch 5 of the first embodiment uses the forward clutch 5a and the reverse brake 5b provided in the forward / reverse switching mechanism of the belt-type continuously variable transmission 6 using planetary gears. That is, the forward clutch 5 a is the second clutch 5 during forward travel, and the reverse brake 5 b is the second clutch 5 during reverse travel.

  The belt-type continuously variable transmission 6 is a transmission that obtains a continuously variable transmission ratio by changing the belt winding diameter by the transmission hydraulic pressure to the primary oil chamber and the secondary oil chamber. The belt-type continuously variable transmission 6 includes a main oil pump 14 (mechanical drive), a sub-oil pump 15 (motor drive), and a first pressure using a line pressure generated by adjusting pump discharge pressure as a primary pressure. A control valve unit (not shown) for generating the second clutch hydraulic pressure and the transmission hydraulic pressure.

  The first clutch 3, the motor / generator 4 and the second clutch 5 constitute a one-motor / two-clutch drive system, and there are “EV mode” and “HEV mode” as main drive modes by this drive system. The “EV mode” is an electric vehicle mode in which the first clutch 3 is disengaged and the second clutch 5 is engaged and only the motor / generator 4 is used as a drive source. Driving in the “EV mode” is referred to as “EV driving”. . The “HEV mode” is a hybrid vehicle mode in which both the clutches 3 and 5 are engaged and the horizontal engine 2 and the motor / generator 4 are used as driving sources, and traveling in the “HEV mode” is referred to as “HEV traveling”.

  The motor / generator 4 has a regenerative cooperative brake unit 16 that controls the total braking torque when the brake is operated, in principle when performing the regenerative operation when the brake is operated. The regenerative cooperative brake unit 16 includes a brake pedal, an electric booster, and a master cylinder, and the electric booster shares a hydraulic braking force by subtracting the regenerative braking force from the required braking force that appears in the pedal operation amount when the brake is operated. In this way, cooperative control for regenerative / hydraulic pressure is performed.

[Power system configuration]
FIG. 1 shows an entire system of an FF plug-in hybrid vehicle, and FIG. 2 shows a power supply system configuration centering on a starter power supply. Hereinafter, based on FIG.1 and FIG.2, the power supply system structure of FF plug-in hybrid vehicle is demonstrated.

  As shown in FIG. 1, the power supply system includes a high-power battery 21 as a motor / generator power supply, a 12V battery 22 as a 12V system load power supply, and a capacitor 23 as a starter power supply.

  The high-power battery 21 is a secondary battery mounted as a power source for the motor / generator 4. For example, a lithium ion battery in which a cell module in which a large number of cells are stacked is set in a battery pack case is used. The high-power battery 21 has a built-in junction box in which relay circuits for supplying / cutting off / distributing high-power are integrated, and further includes a battery temperature adjustment unit 24 having an air conditioner function, a battery charge capacity (battery SOC) and a battery. And a lithium battery controller 86 for monitoring the temperature.

  The high-power battery 21 and the motor / generator 4 are connected via a DC harness 25, an inverter 26, and an AC harness 27. The inverter 26 has a built-in junction box 28 in which relay circuits for supplying / cutting off / distributing strong power are integrated, and further includes a heating circuit 29, an electric air conditioner 30, and a motor controller 83 for performing power running / regenerative control. It is attached. That is, the inverter 26 converts a direct current from the DC harness 25 into a three-phase alternating current to the AC harness 27 during power running for driving the motor / generator 4 by discharging the high-power battery 21. Further, the three-phase alternating current from the AC harness 27 is converted into a direct current to the DC harness 25 during regeneration in which the high-power battery 21 is charged by power generation by the motor / generator 4.

  A rapid external charging port 32 is connected to the high-power battery 21 via a DC harness 31, and a normal external charging port 35 is connected via a DC branch harness 25 ′, a charger 33, and an AC harness 34. . The charger 33 performs AC / DC conversion and voltage conversion. At the time of rapid external charging, for example, the external charging is performed by connecting the connector plug of the charging stand installed in the place of going out to the rapid external charging port 32 (rapid external charging). During normal external charging, external charging is performed by connecting a connector plug from a household power supply to the normal external charging port 35 (normal external charging), for example.

  The 12V battery 22 is a secondary battery mounted as a power source for a 12V system load 36, which is another auxiliary machine except the starter motor 1, for example, a lead battery generally mounted in an engine vehicle or the like. Is used. The high voltage battery 21 and the 12V battery 22 are connected via a DC branch harness 25 ″, a DC / DC converter 37, and a battery harness 38. The DC / DC converter 37 changes the voltage of several hundred volts from the high voltage battery 21 to 12V. The DC / DC converter 37 is controlled by the hybrid control module 81 to manage the charge amount of the 12V battery 22.

  The capacitor 23 is a power storage device mounted as a dedicated power source for the starter motor 1 and has a large electrostatic capacity and has an excellent rapid charging / discharging performance (eDLC: electric Double Layer Capacitor). What is called is used. As shown in FIG. 2, the auxiliary load power supply system 39 and the capacitor 23 are connected via a battery branch harness 38 ′ provided with a fuse 40 and a capacitor charging circuit 41. The capacitor 23 and the starter motor 1 are connected via a capacitor harness 42, a resistor 43, and a relay switch 44. The capacitor 23 and the capacitor charging circuit 41 constitute a DLC unit 45, and the starter motor 1 and the relay switch 44 constitute a starter unit 46. Hereinafter, detailed configurations of the DLC unit 45 and the starter unit 46 will be described.

  As shown in FIG. 2, the DLC unit 45 includes a capacitor 23, a capacitor charging circuit 41, a spontaneous discharge switch 47, a forced discharge switch 48, a cell voltage monitor 49, and a capacitor temperature sensor 50 (capacitor temperature). Detecting means).

  The capacitor 23 is configured by connecting a plurality of DLC cells in series / parallel. The spontaneous discharge switch 47, the forced discharge switch 48, and the capacitor temperature sensor 50 are provided at both ends of the plurality of DLC cells. Provided in parallel. The cell voltage monitor 49 is provided in parallel to each DLC cell so as to detect the cell voltage (= capacitor capacity) of each of the plurality of DLC cells.

  The capacitor charging circuit 41 is constituted by a DC / DC converter circuit (a combination circuit of a switching element, a choke coil, a capacitor and a diode) with a built-in semiconductor relay by a switching method. The capacitor charging circuit 41 includes a semiconductor relay 51 and a DC / DC converter 52 that are controlled by a hybrid control module 81. The semiconductor relay 51 is a non-contact relay using a semiconductor switching element. For example, as schematically shown in the lower left part of FIG. 2, a light called a photocoupler that transmits an isolated input / output space with a light signal. The configuration uses a semiconductor. The semiconductor relay 51 has a switch function for disconnecting or connecting the capacitor 23 from the auxiliary load power supply system 38. The DC / DC converter 52 has a function of converting 12V direct current to 13.5V direct current and a function of switching capacitor charging current.

  The starter unit 46 includes a starter motor 1, a relay switch 43, an electromagnetic actuator 53, and a pinion shift mechanism 54.

  The electromagnetic actuator 53 turns on the relay switch 44 and shifts the pinion 57 of the pinion shift mechanism 54 to a position where it meshes with the ring gear 58 by electromagnetic force generated by energizing the two coils 55 and 56. When the energization is cut off, the relay switch 44 is turned off and the pinion 57 is shifted to a position where the engagement with the ring gear 58 is released. The ring gear 58 is provided on the crankshaft of the horizontal engine 2. The auxiliary load power supply system 39 and the two coils 55 and 56 are connected via a battery branch harness 38 ″ provided with a starter cut-off relay 59, a HEV / IS / relay 60, and a starter relay 61. Energization / cutoff of the off relay 59 is performed by a body control module 87. Energization / cutoff of the HEV / IS / relay 60 is performed by a hybrid control module 81. Energization / cutoff of the starter relay 61 is performed by an underhood switching module. The voltage sensor 62 for relay diagnosis is provided at a position where the battery branch harness 38 "intersects.

  The pinion shift mechanism 54 has a pinion 57 provided so as to be movable in the axial direction with respect to the motor shaft of the starter motor 1, one end connected to the electromagnetic actuator 53, and the other end fitted into the shift groove of the pinion 57. Shift lever 63.

[Control system configuration]
1 shows an overall system of an FF plug-in hybrid vehicle, FIG. 2 shows a power supply system configuration centering on a starter power supply, and FIG. 3 shows a control system configuration. Hereinafter, the control system configuration of the FF plug-in hybrid vehicle will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the control system includes a hybrid control module 81 (abbreviation: “HCM”) as an integrated control unit having a function of appropriately managing the energy consumption of the entire vehicle. Control means connected to the hybrid control module 81 include an engine control module 82 (abbreviation: “ECM”), a motor controller 83 (abbreviation: “MC”), and a CVT control unit 84 (abbreviation: “CVTCU”). Have. The data communication module 85 (abbreviation: “DCM”) and the lithium battery controller 86 (abbreviation: “LBC”) are included. Furthermore, it has a body control module 87 (abbreviation: “BCM”) and an underhood switching module 88 (abbreviation: “USM”). These control means include CAN communication line 90 (CAN is an abbreviation for “Controller Area Network”) except for a LIN communication line 89 (LIN: abbreviation for “Local Interconnect Network”) that connects hybrid control module 81 and DLC unit 45. Is connected so that bidirectional information can be exchanged.

  The hybrid control module 81 performs various controls based on input information from each control means, an ignition switch 91, an accelerator opening sensor 92, a vehicle speed sensor 93, and the like. Among these, the control performed for the purpose of driving the FF plug-in hybrid vehicle capable of external charging with high fuel efficiency is a travel mode based on the battery SOC of the high-power battery 21 (“CD mode”, “CS mode”). (Running mode selection control means).

  The “CD mode (Charge Depleting mode)” is a mode in which priority is given to EV travel that consumes the power of the high-power battery 21 in principle. For example, while the battery SOC of the high-power battery 21 decreases from full SOC to set SOC. Is selected. However, HEV traveling is exceptionally performed in high-load traveling where driving force is insufficient in EV traveling. The start of the horizontal engine 2 during the selection of the “CD mode” is based on the start by the starter motor 1 (starter start) in principle, with the exception of the start by the motor / generator 4 (M / G start).

  The “CS mode (Charge Sustain mode)” is a mode in which priority is given to HEV running that maintains the power of the high-power battery 21 in principle, and is selected when the battery SOC of the high-power battery 21 is equal to or lower than the set SOC. That is, when it is necessary to maintain the battery SOC of the high-power battery 21 within a predetermined range, HEV traveling is performed by engine power generation that causes the motor / generator 4 to generate electric power by driving the lateral engine 2. The start of the horizontal engine 2 during the selection of the “CS mode” is based on the start by the motor / generator 4 (M / G start), except for the start by the starter motor 1 (starter start). Note that the “set SOC” that is the mode switching threshold is between the threshold when CD mode → CS mode (for example, about 20%) and the threshold when CS mode → CD mode (for example, about 25%). Has hysteresis.

The hybrid control module 81 performs engine start control by the starter motor 1, charge control to the capacitor 23, and discharge control from the capacitor 23 in addition to the selection control of “CD mode” and “CS mode”. Furthermore, the following starter start related control is performed.
(A) Time-saving control from engine start to starter start permission.
(B) Time shortening control from ignition on to starter start permission.
(C) Deterioration progress suppression control of the capacitor 23.
(D) Control of countermeasures for high / low temperature of capacitor 23 (Example 1).
(E) Prevention of voltage sag of auxiliary equipment for vehicles.

  The engine control module 82 performs fuel injection control, ignition control, fuel cut control, and the like of the horizontal engine 2. The motor controller 83 performs power running control, regeneration control, and the like of the motor generator 4 by the inverter 26. The CVT control unit 84 performs engagement hydraulic pressure control of the first clutch 3, engagement hydraulic pressure control of the second clutch 5, shift hydraulic pressure control of the belt type continuously variable transmission 6, and the like. When the switch of the portable remote control key is remotely operated and the communication is established with the portable remote control key, the data communication module 85 controls, for example, lock / unlock of the charging port lid and the connector lock mechanism. The lithium battery controller 86 manages the battery SOC, battery temperature, and the like of the high-power battery 21. The body control module 87 performs energization / cutoff control of the starter cut-off relay 59. The under hood switching module 87 performs energization / cut-off control of the built-in starter relay 61 based on the range position signal from the inhibitor switch 94.

[Detailed configuration of capacitor charge / discharge control]
FIG. 4 shows a capacitor charge / discharge control processing flow executed by the hybrid control module 81 (capacitor charge / discharge control means). Hereinafter, each step of FIG. 4 showing the capacitor charge / discharge control processing configuration will be described.

In step S1, it is determined whether or not there has been a mode reverse transition for switching the travel mode from the “CS mode” to the “CD mode” by the travel mode selection control. If Yes (CS → CD mode reverse transition is present), the process proceeds to step S2. If No (CS → CD mode reverse transition is not present), the process proceeds to the end.
Here, during the selection of the “CS mode”, the capacitor voltage is set to a voltage b or less at which deterioration does not proceed. Here, as the “voltage b at which the deterioration does not proceed”, it has been found that the deterioration does not proceed if the voltage is 1 V or less per cell of the capacitor 23. For example, when six cells are connected in series, the deterioration due to the increase in the internal resistance. Is set to 6.0V, which suppresses the progress of.

In step S2, following the determination that CS → CD reverse transition is present in step S1, it is determined whether or not the capacitor temperature is equal to or lower than the deterioration prevention threshold value α. If Yes (capacitor temperature ≦ degradation prevention threshold value α), the process proceeds to step S3. If No (capacitor temperature> degradation prevention threshold value α), the process proceeds to step S5.
Here, the “deterioration prevention threshold α” is set to a temperature range (for example, 55 ° C. to 60 ° C.) that is slightly lower than the limit temperature at which gas or the like may be generated from the cell of the capacitor 23.

In step S3, following the determination in step S2 that the capacitor temperature ≦ the deterioration prevention threshold value α, or the determination in step S4 that the capacitor voltage <the starter start permission voltage a, the normal charging current 1 causes the capacitor 23 is recharged, and the process proceeds to step S4.
Here, as the charging current 1 for recharging the capacitor 23, a charging current (for example, 15A) aimed at shortening the time required for recharging up to the starter start permission voltage a is selected.

In step S4, following the recharging with the charging current 1 in step S3, it is determined whether or not the capacitor voltage is equal to or higher than the starter start permission voltage a. If Yes (capacitor voltage ≧ starter start permission voltage a), the process proceeds to the end. If No (capacitor voltage <starter start permission voltage a), the process returns to step S3.
Here, the “starter start permission voltage a” is set to about 12.5 V within which the required starter start time is within the target time in the case of the capacitor 23 having a full charge and a capacitor voltage of 13.5 V in the first embodiment, for example. .

In step S5, following the determination that capacitor temperature> deterioration prevention threshold value α in step S2 or the determination that capacitor voltage <starter start permission voltage a in step S6, a charging current smaller than charging current 1 The capacitor 23 is recharged by 2 (<charging current 1), and the process proceeds to step S6.
Here, as the charging current 2 for recharging the capacitor 23, a charging current (for example, 7.5 A) aimed at suppressing the progress of deterioration due to heat generation of the capacitor 23 is selected.

In step S6, following the recharging with the charging current 2 in step S5, it is determined whether or not the capacitor voltage is equal to or higher than the starter start permission voltage a. If Yes (capacitor voltage ≧ starter start permission voltage a), the process proceeds to the end. If No (capacitor voltage <starter start permission voltage a), the process returns to step S5.
Here, the “starter start permission voltage a” is the same voltage value as in step S4.

Next, the operation will be described.
The operation of the control device for the FF plug-in hybrid vehicle of the first embodiment is divided into [characteristic operation by the capacitor power supply circuit configuration], [charge / discharge operation by the capacitor power supply], and [capacitor recharge control operation at the time of reverse transition]. To do.

[Characteristic effect of capacitor power circuit configuration]
For example, in an idle stop vehicle, when the starter motor power supply is a 12V battery, the power supply circuit configuration is a configuration in which the DLC unit 45 and the fuse 40 are removed from the capacitor power supply circuit configuration of the first embodiment. To do.

  In the case of this comparative example, the power supply of the starter motor and the vehicle auxiliary machines is shared by one 12V battery. For this reason, if the starter motor is used to start the engine when the required amount of power in the vehicle auxiliaries is high, the supply power is insufficient, and the voltage of the vehicle auxiliaries decreases suddenly at the moment of starting the engine. Low occurs.

  On the other hand, in the first embodiment, the auxiliary load power supply system 39 is configured by connecting the high-power battery 21 and the 12V battery 22 via the DC / DC converter 37. The DLC unit 45 includes a capacitor charging circuit 41 that is branched and connected from the DC / DC converter 37 and a capacitor 23 that is connected to the capacitor charging circuit 41. A capacitor power supply circuit is configured by providing a semiconductor relay 51 as a switch built in the capacitor charging circuit 41 between the auxiliary load power supply system 39 and the DLC unit 45.

  With this configuration, the 12V battery 22 and the capacitor 23 are charged with the electric power from the high-power battery 21, and the necessary power is supplied from the 12V battery 22 to the 12V system load 36, which is a vehicle auxiliary device. To supply the necessary power. That is, the starter motor 1 and the 12V system load 36 do not share the power source, and the two power sources including the 12V battery 22 and the capacitor 23 receive a charge backup by the high-power battery 21.

  And the capacitor power supply circuit is comprised by adding the DLC unit 45 (capacitor charging circuit 41 + capacitor 23), without changing the power supply circuit structure of the idle stop vehicle which is a comparative example. Thus, since the DLC unit 45 can be added in the same manner as the addition of auxiliary equipment, the control of the high-power battery 21 and the DC / DC converter 37 does not need to be changed from the control of the comparative example.

  Further, when the charge / discharge balance of the auxiliary load power supply system 39 is likely to be lost, the DLC unit 45 (capacitor charging circuit 41 + capacitor 23) can control the charging current and the auxiliary relay load by the semiconductor relay 51 as a switch. The power supply system 39 can be disconnected. For this reason, by opening the semiconductor relay 51 at the start of the starter, it is possible to prevent a voltage sag in which the voltage of the vehicle auxiliary machinery suddenly decreases. In addition, it is not necessary to change the converter capacity of the DC / DC converter 37 and the battery capacity of the 12V battery 22 from the converter capacity and battery capacity set in the comparative example.

[Charging / discharging action by capacitor power supply]
“Engine start control operation by starter motor 1”, “charge control operation to capacitor 23”, and “discharge control operation from capacitor 23” performed by hybrid control module 81 on the capacitor power supply circuit will be described.

The engine start by the starter motor 1 is based on the output of the starter start command from the hybrid control module 81. When the HEV / IS / relay 60 is energized, the relay switch 44 is turned on and the pinion 57 is shifted to a position where it engages with the ring gear 58. To do. As a result, the starter motor 1 using the capacitor 23 as a power source rotates the crankshaft of the horizontal engine 2 to start the starter, and the HEV / IS / relay 60 is cut off after a predetermined time from energization. The starter cut-off relay 59 is energized by the body control module 87 except when a vehicle condition prohibiting engine start is satisfied. Further, the starter relay 61 built in the underhood switching module 88 is energized only when the P range is selected, and is in a cut-off state when a D range other than the P range is selected.
Therefore, in principle, the engine start control by the starter motor 1 is performed by using the power of the capacitor 23 while the HEV / IS / relay 60 is energized by the starter start command under the starter start permission condition. Then, the horizontal engine 2 is started.
In addition to the starter start described above, the engine start control includes an M / G start for starting the transverse engine 2 using the motor / generator 4 as a starter motor (engine start control means).

For charging the capacitor 23, the semiconductor relay 51 of the capacitor charging circuit 41 is closed based on the output of the charging command from the hybrid control module 81, and the capacitor charging current is selected. Thereby, the electric power from the high-power battery 21 is introduced into the capacitor 23 through the DC / DC converter 37 → the fuse 40 → the semiconductor relay 51 → the DC / DC converter 52, so that the short-time charging according to the capacitor charging current can be performed. Done. The capacitor charging current has a charging current 1 (for example, 15 A) as a normal current, and has a charging current 2 (for example, 7.5 A) that can be selected by changing from the charging current 1 as an exception.
Therefore, the charging control to the capacitor 23 uses the power from the high-power battery 21 and charges the capacitor 23 with the selected capacitor charging current while the charging command is output.

Based on the output of the natural discharge command from the hybrid control module 81, the discharge from the capacitor 23 causes the natural discharge from the capacitor 23 by closing the natural discharge switch 47 of the DLC unit 45. Further, the forced discharge from the capacitor 23 is performed by closing the forced discharge switch 48 of the DLC unit 45 based on the output of the forced discharge command from the hybrid control module 81. In the case of this forced discharge, the discharge amount per unit time is set larger than that in the case of natural discharge.
Therefore, in the forced discharge control to the capacitor 23, while the forced discharge switch 48 is closed based on the forced discharge command, the power of the capacitor 23 is converted into resistance heat, and discharge is performed in a shorter time than natural discharge. .
Therefore, the forced discharge control to the capacitor 23 is discharged from the high-power battery 21 by the selected capacitor discharge current while the discharge command is output.

[Capacitor recharge control during reverse transition]
As described above, the FF plug-in hybrid vehicle capable of external charging is intended to run with high fuel efficiency, and the running mode selection control is performed based on the battery SOC of the high-power battery 21. In this travel mode selection control, in principle, the “CD mode” that prioritizes EV travel that consumes the power of the high-power battery 21 while the battery SOC of the high-power battery 21 decreases from the full SOC to the set SOC (= threshold). Selected. When the battery SOC of the high-power battery 21 becomes equal to or lower than the set SOC (= threshold), the “CS mode” that gives priority to HEV traveling that maintains the power of the high-power battery 21 is selected in principle. Further, the horizontal engine 2 is started when the “CD mode” is selected. In principle, the starter motor 1 is started (starter start). The horizontal engine 2 is started when the “CS mode” is selected. In principle, start with 4 (M / G start).

  Therefore, when the reverse transition from the “CS mode” to the “CD mode” is performed using the travel mode selection control information and the capacitor temperature information, which are characteristics of the plug-in hybrid vehicle, the temperature protection of the capacitor 23 is performed. It is capacitor recharge control at the time of reverse transition of Example 1.

  In other words, during the selection of the “CS mode” based on M / G starting, it is not necessary to increase the capacitor voltage in preparation for starter starting, and the internal resistance increases if the capacitor remains fully charged. Since the deterioration progresses, if it is not used, the life is extended by discharging to a voltage b or less where the deterioration does not proceed. On the other hand, during the selection of the “CD mode” based on the starter start principle, the capacitor voltage is increased in advance in order to enable the starter start in response to the starter start command without waiting for the capacitor charging time. There is a need.

  Therefore, when there is a reverse transition from the “CS mode” to the “CD mode”, the capacitor 23 is recharged. However, if only the starter start is prioritized and recharging is performed with a large current, the capacitor 23 Deterioration progresses. Hereinafter, based on FIG. 4, the capacitor recharge control action at the time of reverse transition performed reflecting this will be described.

First, when there is no mode reverse transition for switching the travel mode from the “CS mode” to the “CD mode” by the travel mode selection control, the process proceeds from step S1 to end in the flowchart of FIG. On the other hand, when there is a mode reverse transition in which the travel mode is switched from the “CS mode” to the “CD mode” by the travel mode selection control, the process proceeds from step S1 to step S2 onward in the flowchart of FIG.
That is, normally, since the battery SOC of the high-power battery 21 is maintained in the “CS mode”, the reverse transition from the “CS mode” to the “CD mode” cannot occur. However, for example, when regeneration is continued on a long downhill or the like going from a high mountain to a flat land, the charge amount to the high-power battery 21 is large, so that the battery SOC that can shift to the “CD mode” can be recovered. Can happen. Along with the reverse mode transition from “CS mode” to “CD mode”, the capacitor 23 is recharged by the flow proceeding to step S2 and subsequent steps in preparation for the starter start in the “CD mode”.

  When there is a mode reverse transition to switch from the “CS mode” to the “CD mode” and the capacitor temperature is equal to or lower than the deterioration prevention threshold value α, in the flowchart of FIG. 4, step S1 → step S2 → step S3 → step Proceed to S4. While it is determined in step S4 that the capacitor voltage is less than the starter start permission voltage a, the flow of going from step S3 to step S4 is repeated, and in step S4, the capacitor voltage is equal to or higher than the starter start permission voltage a. Then go to the end. That is, when the “CS mode” is switched to the “CD mode” when the capacitor temperature is low, the capacitor 23 is recharged at a high charge rate until the starter start permission voltage a becomes equal to or higher than the charge current 1.

  On the other hand, when there is a mode reverse transition to switch from the “CS mode” to the “CD mode” and the capacitor temperature exceeds the deterioration prevention threshold value α, step S1 → step S2 → step in the flowchart of FIG. The process proceeds from S5 to step S6. While it is determined in step S6 that the capacitor voltage is less than the starter start permission voltage a, the flow of going from step S5 to step S6 is repeated, and in step S6, the capacitor voltage is equal to or higher than the starter start permission voltage a. Then go to the end. That is, when the “CS mode” is switched to the “CD mode” when the capacitor temperature is high, the capacitor 23 is slowly charged until the starter start permission voltage a is exceeded by the charging current 2 (<charging current 1). Recharged at

As described above, in the first embodiment, when there is a reverse transition from the “CS mode” to the “CD mode”, the higher the capacitor temperature, the smaller the charging current, and the capacitor 23 is recharged to start the starter. The structure provided is adopted (FIG. 4).
That is, when the capacitor temperature is low, the charging current is increased, thereby shortening the waiting time until the starter is started. On the other hand, when the capacitor temperature is high, the charging current is reduced as the capacitor temperature is higher, so that the deterioration of the capacitor 23 due to heat generation can be suppressed.
As a result, when there is a reverse transition from the “CS mode” to the “CD mode”, it is possible to extend the capacitor life while shortening the starter start waiting time.

In the first embodiment, when there is a reverse transition from the “CS mode” to the “CD mode”, if the capacitor temperature is equal to or lower than the deterioration prevention threshold value α, the capacitor 23 is recharged with the charging current 1. If the capacitor temperature exceeds the deterioration prevention threshold value α, a configuration is adopted in which the capacitor 23 is recharged with a charging current 2 smaller than the charging current 1 (FIG. 4).
That is, the deterioration prevention threshold value α is determined as the boundary temperature, and the charging current is made different between the case where the capacitor temperature is a low temperature range equal to or lower than the deterioration prevention threshold value α and the case where the capacitor temperature is a high temperature range exceeding the deterioration prevention threshold value α.
Accordingly, it is possible to achieve both the shortening of the starter start waiting time and the extension of the capacitor life while performing simple control for switching between the two charging currents.

In the first embodiment, when the “CS mode” is selected, the capacitor voltage is maintained at a voltage b or less at which the deterioration of the capacitor 23 does not proceed, and the capacitor 23 is switched along with the reverse transition from the “CS mode” to the “CD mode”. When recharging, a configuration is adopted in which the capacitor voltage is increased until the starter start permission voltage a becomes equal to or higher (FIG. 4).
That is, when the “CS mode” is selected, the capacitor voltage is kept below the voltage b at which the deterioration does not proceed, so that the capacitor 23 is deteriorated as compared with the case where a voltage that can always be fully charged or started is maintained. Progress is suppressed. In addition, by performing the process until the capacitor voltage becomes equal to or higher than the starter start permission voltage a, it is possible to prepare for the starter start in the “CD mode” earlier than in the case where recharging is performed until the capacitor voltage is fully charged.
Therefore, if the reverse transition from the “CS mode” to the “CD mode” occurs while suppressing the deterioration of the capacitor 23 when the “CS mode” is selected, it is possible to prepare for the starter start early.

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

(1) The drive system has a starter motor 1, an engine (horizontal engine 2), and a motor / generator 4.
As a power supply system, a high-power battery 21 as a power source of the motor / generator 4, a capacitor 23 as a power source of the starter motor 1, and capacitor charge / discharge control means (hybrid control module 81) for controlling charge / discharge of the capacitor 23. And a control device for a plug-in hybrid vehicle (FF plug-in hybrid vehicle) capable of external charging to the high-power battery 21,
Engine start control means (hybrid control module 81) for starting the engine (horizontal engine 2) by starter start or motor / generator start (M / G start);
When the charge capacity (battery SOC) of the high-power battery 21 is equal to or greater than the threshold, the “CD mode” for starting the engine (horizontal engine 2) is selected in principle, and the charge capacity of the high-power battery 21 is less than the threshold. In principle, a traveling mode selection control means (hybrid control module 81) for selecting a “CS mode” for starting the motor (generator) (M / G starting) of the engine (horizontal engine 2);
Capacitor temperature detecting means (capacitor temperature sensor 50) for detecting the temperature of the capacitor 23, and
When there is a reverse transition from the “CS mode” to the “CD mode”, the capacitor charge / discharge control means (hybrid control module 81) reduces the charging current as the capacitor temperature increases, Recharge and prepare for starter start (FIG. 4).
For this reason, when there is a reverse transition from the “CS mode” to the “CD mode”, it is possible to extend the capacitor life while shortening the starter start waiting time.

(2) The capacitor charging / discharging control means (hybrid control module 81), when there is a reverse transition from the “CS mode” to the “CD mode”, if the capacitor temperature is equal to or lower than the degradation prevention threshold value α, If the capacitor 23 is recharged with one charging current (charging current 1) and the capacitor temperature exceeds the deterioration prevention threshold value α, a second charging current (charging) that is smaller than the first charging current (charging current 1). The capacitor 23 is recharged with current 2) (FIG. 4).
For this reason, in addition to the effect of (1), it is possible to achieve both the shortening of the starter start waiting time and the extension of the capacitor life while performing simple control for switching between the two charging currents 1 and 2. it can.

(3) When the “CS mode” is selected, the capacitor charge / discharge control means (hybrid control module 81) maintains the capacitor voltage below the voltage b at which the deterioration of the capacitor 23 does not proceed, and the “CS mode”. When the capacitor 23 is recharged along with the reverse transition from “CD mode” to “CD mode”, the operation is continued until the capacitor voltage becomes equal to or higher than the starter start permission voltage a (FIG. 4).
Therefore, in addition to the effect of (1) or (2), if there is a reverse transition from the “CS mode” to the “CD mode” while suppressing the progress of deterioration of the capacitor 23 when the “CS mode” is selected, Can be prepared for starter start.

  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, as the capacitor charge / discharge control means, when there is a reverse transition from the “CS mode” to the “CD mode”, if the capacitor temperature is equal to or lower than the deterioration prevention threshold value α, the charging current 1 An example is shown in which recharging is performed and the capacitor 23 is recharged with a charging current 2 smaller than the charging current 1 if the capacitor temperature exceeds the deterioration prevention threshold value α. However, as a capacitor charge / discharge control means, when there is a reverse transition from “CS mode” to “CD mode”, the capacitor temperature is divided into three or more temperature ranges, and the charging current is changed in multiple stages. It is also possible to change the charging current steplessly according to the capacitor temperature. That is, when there is a reverse transition from the “CS mode” to the “CD mode”, the higher the capacitor temperature, the smaller the charging current and the recharging of the capacitor.

  In the first embodiment, as an example of the capacitor charge / discharge control means, when there is a reverse transition from the “CS mode” to the “CD mode”, recharge is performed up to the starter start permission voltage a. However, the capacitor charge / discharge control means may be an example of recharging until full charge when there is a reverse transition from the “CS mode” to the “CD mode”. Further, an example in which the voltage b or less at which the deterioration does not proceed during the selection of the “CS mode” has been shown. However, for example, the capacitor voltage may be made zero by forced discharge.

  In Example 1, the example which performs recharge control using driving mode information, capacitor temperature information, and capacitor voltage information as a capacitor charging / discharging control means was shown. However, the capacitor charge / discharge control means may be an example in which recharge or forced discharge is controlled using capacitor capacity information instead of capacitor voltage information. That is, when the capacitor capacity is Q, the capacitance is C, and the capacitor voltage is V, Q = C · V. When the capacitance C is constant, the capacitor capacity Q is proportional to the capacitor voltage V. Thus, even if capacitor capacity information is used instead of capacitor voltage information, equivalent control is achieved.

  In the first embodiment, the hybrid control module 81 is used as the capacitor charge / discharge control means. However, as the capacitor charge / discharge control means, an independent power supply system controller may be used, or an example in which a power supply system capacitor charge / discharge control unit is provided in a controller other than the hybrid control module may be used. .

  In Example 1, the example which applies the control apparatus of this invention to FF plug-in hybrid vehicle was shown. However, the control device of the present invention can be applied not only to FF plug-in hybrid vehicles but also to FR plug-in hybrid vehicles and 4WD plug-in hybrid vehicles. In short, the present invention can be applied to any plug-in hybrid vehicle that includes a capacitor as a starter power source and can externally charge a high-power battery.

1 Starter motor 2 Horizontal engine (engine)
3 First clutch 4 Motor / generator 5 Second clutch 6 Belt type continuously variable transmissions 10R, 10L Left and right front wheels 11R, 11L Left and right rear wheels 21 High power battery 22 12V battery 23 Capacitor 32 Rapid external charging port 33 Charger 35 Normal external charging Port 37 DC / DC converter 41 Capacitor charging circuit 45 DLC unit 49 Cell voltage monitor 50 Capacitor temperature sensor (capacitor temperature detecting means)
51 Semiconductor relay 52 DC / DC converter 81 Hybrid control module (capacitor charge / discharge control means, engine start control means, travel mode selection control means)

Claims (3)

The drive system has a starter motor, an engine, and a motor / generator.
The power supply system includes a high-power battery that is a power source of the motor / generator, a capacitor that is a power source of the starter motor, and a capacitor charge / discharge control unit that controls charge / discharge of the capacitor, and is external to the high-power battery. In a control device for a plug-in hybrid vehicle capable of charging,
Engine start control means for starting the engine by starter start or motor / generator start;
When the charge capacity of the high-power battery is equal to or greater than a threshold, the CD mode for starting the engine is selected in principle, and when the charge capacity of the high-power battery is less than the threshold, the engine is generally started with a motor / generator. Driving mode selection control means for selecting,
Capacitor temperature detecting means for detecting the temperature of the capacitor; and
The capacitor charge / discharge control means prepares for the starter start by reducing the charging current and recharging the capacitor as the capacitor temperature increases when there is a reverse transition from the CS mode to the CD mode. A control device for a plug-in hybrid vehicle. In the control device for the plug-in hybrid vehicle according to claim 1,
The capacitor charge / discharge control means recharges the capacitor with a first charging current when the capacitor temperature is equal to or lower than a deterioration prevention threshold when there is a reverse transition from the CS mode to the CD mode. The control device for a plug-in hybrid vehicle, wherein the capacitor is recharged with a second charging current smaller than the first charging current if the temperature exceeds a deterioration prevention threshold. In the control device for a plug-in hybrid vehicle according to claim 1 or 2,
When the CS mode is selected, the capacitor charge / discharge control means maintains the capacitor voltage below a voltage at which the deterioration of the capacitor does not proceed, and restarts the capacitor with the reverse transition from the CS mode to the CD mode. A control device for a plug-in hybrid vehicle, wherein charging is performed until the capacitor voltage becomes equal to or higher than a starter start permission voltage.