JP3730246B2 - Control device and control method for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control charging/discharging amounts in order to protect a battery in accordance with the conditions of over-discharge of the battery. <P>SOLUTION: The controlling equipment of the hybrid vehicle is provided with an engine 1, a motor 2 directly connected to the engine 1 to generate auxiliary driving power, a battery 3 supplying electric power to the motor 2 additionally to be charged with electric energy obtained by operating the motor 2 as a generator, a contactor 11 intermittently performing supply of a current between the battery 3 and the motor 2, an electric load with electric power supplied by generated power of the motor 2 and the battery 3, an engine stopping means for stopping the engine 1 by a prescribed operation condition, a mode discrimination means for discriminating whether the engine 1 is placed in an idling operation condition or in a stopped condition, and a battery protection means, restarting the engine 1 in the case of detecting over-discharge of the battery 3 when the engine 1 is discriminated to be in a stopped condition by the mode discrimination means and cutting the contactor 11 in the case of a further over-discharge. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a control device and a control method for controlling a charge / discharge amount of a battery in order to protect a battery mounted on a hybrid vehicle.

Conventionally, a hybrid vehicle provided with a motor in addition to an engine is known as a driving power source. Hybrid vehicles include series hybrid vehicles and parallel hybrid vehicles. A series hybrid vehicle is a vehicle in which a motor is driven using a power generation output of a generator driven by an engine and wheels are driven by the motor.
Therefore, since the engine and the wheel are not mechanically connected, the engine can be operated at a substantially constant rotation in the high-fuel-consumption, low-emission speed range, and the fuel consumption and the low emission are better than those of conventional engine vehicles. realizable.

On the other hand, a parallel hybrid vehicle uses a motor connected to the engine to assist driving of the engine drive shaft, and the electric energy obtained by using the motor as a generator is charged to the power storage device. The electrical energy is also used for electrical components in the vehicle.
Therefore, since the driving load of the engine can be reduced, it is possible to realize better fuel consumption and lower emission compared to conventional engine vehicles.

In the parallel hybrid vehicle, a motor that assists the output of the engine is directly connected to the output shaft of the engine, and this motor functions as a generator when decelerating or the like and stores electricity in a battery or the like (for example, see Patent Document 1). ), A type that can generate a driving force in either the engine or the motor, or both, and that has a separate generator.
In such a hybrid vehicle, for example, the motor output is assisted by the motor during acceleration, and the battery is charged by deceleration regeneration during deceleration. (Hereinafter referred to as “remaining battery capacity”) can be secured to meet the demands of the driver.
JP-A-5-49101

  By the way, the battery used for the hybrid vehicle is configured to supply a shortage of electric power to the electric component when the electric power supplied to the electric component included in the vehicle exceeds the electric power generated by the motor. Therefore, when the engine is in an idling state, the electric power consumed by the electrical component tends to exceed the electric power generated by the motor, and the battery is likely to be overdischarged. Furthermore, when the battery of the hybrid vehicle is in an overdischarged state, it is necessary to run only with the engine, which causes a problem of deterioration in fuel consumption and power performance.

  The present invention has been made in view of such circumstances, and detects a battery overdischarge state and controls a charge / discharge amount for battery protection in accordance with the detected overdischarge state. A control device and a control method are provided.

The invention according to claim 1 is directed to an engine (for example, the engine 1 in the embodiment) that outputs a driving force of a vehicle, and a motor (for example, an implementation) that generates an auxiliary driving force that is directly connected to the engine and assists the output of the engine. Motor 2) in the embodiment, and a battery for supplying electric energy to the motor and charging electric energy obtained by operating the motor as a generator when no auxiliary driving force is required (for example, battery 3 in the embodiment) A contactor for intermittently supplying current between the battery and the motor (for example, the main contactor 11 in the embodiment), and the electric load generated by the motor and the electric load (for example, in the embodiment). An electrical component (not shown) and an engine stop for stopping the engine according to predetermined operating conditions. (For example, the engine control device 4 in the embodiment), the mode determining means (for example, the mode determining unit 52 in the embodiment) for determining whether the engine is idling or stopped, and the mode determining means, the engine is stopped. Battery protection means for instructing restart of the engine when it is detected that the battery is overdischarged, and for disconnecting the contactor when overdischarge has progressed after the engine restart instruction (For example, the charge / discharge control unit 54 in the embodiment).
By configuring in this way, when an overdischarge of the battery is detected when it is determined that the engine is stopped, the engine is restarted by instructing the engine to be restarted. The generated power can be stored in the battery. In addition, when the overdischarge further progresses after the engine restart instruction , the contactor is disconnected, so that the discharge from the battery can be completely stopped and the overdischarge of the battery can be prevented from proceeding. .

According to a second aspect of the present invention, in the first aspect of the invention, when the battery protection unit detects an overdischarge of the battery when the engine is determined to be in an idling operation state by the mode determination unit, When the engine idle speed is increased and further overdischarge proceeds, the power supply to the electric load is stopped.
By configuring in this way, when the engine is determined to be in an idling operation state, if the battery overdischarge is detected, the engine idling speed is increased, so that the amount of power generated by the motor can be increased and insufficient. You can make up for power. In addition, if the overdischarge further progresses, the power supply to the electric load is stopped, so the load on the battery can be reduced, and all the power generated by the motor can be used for charging the battery. Overdischarge can be recovered.

According to a third aspect of the present invention, in the first aspect of the invention, the battery protection unit is a determination map that is referred to when the engine is determined to be stopped by the mode determination unit (for example, the determination map in the embodiment). 53b), and the determination map instructs the engine to be restarted when the remaining battery capacity falls below a first set capacity, and the remaining battery capacity is greater than the first set capacity after the engine restart instruction. The contactor is defined to be disconnected when it falls below a small second set capacity.
With this configuration, when the remaining battery capacity falls below the first set capacity when the engine is determined to be stopped, the engine is restarted by instructing the engine to restart. Can be resumed, and the generated power can be stored in the battery. In addition, since the contactor is disconnected when the remaining battery capacity falls below the second set capacity after the engine restart instruction , the discharge from the battery can be completely stopped and the battery overdischarge is prevented from proceeding. can do.

According to a fourth aspect of the present invention, in the first aspect of the invention, the battery protection unit is a determination map that is referred to when the engine is determined to be stopped by the mode determination unit (for example, the determination map in the embodiment). 53b), the determination map instructs the engine to be restarted when the battery voltage falls below the first set voltage, and the battery voltage is smaller than the first set voltage after the engine restart instruction . The contactor is defined to be disconnected when the set voltage is lower than 2.
With this configuration, if the battery voltage falls below the first set voltage when it is determined that the engine is stopped, the engine is restarted by instructing the engine to restart. It can be resumed and the generated power can be stored in the battery. Further, since the contactor is disconnected when the battery voltage falls below the second set voltage after the engine restart instruction , the discharge from the battery can be completely stopped, and the battery overdischarge is prevented from proceeding. be able to.

The invention according to claim 5 is the invention according to claim 2, wherein the battery protection means is a determination map (for example, determination in the embodiment) that is referred to when the engine is determined to be in an idling operation state by the mode determination means. A map 53a), wherein the determination map increases the idle speed of the engine when the remaining battery capacity falls below the first set capacity, and the second remaining battery capacity is smaller than the first set capacity. It is defined that the power supply to the electric load is stopped when it falls below a set capacity.
  With this configuration, when the remaining battery capacity falls below the first set capacity when the engine is determined to be in the idling operation state, the engine idle speed is increased, so that the amount of power generated by the motor is increased. Can compensate for the lack of power. Furthermore, since the power supply to the electric load is stopped when the remaining battery capacity falls below the second set capacity, the load on the battery can be reduced, and all the electric power generated by the motor can be used for charging the battery. The battery can be recovered from overdischarge.

The invention according to claim 6 is the invention according to claim 2, wherein the battery protection means is a determination map (for example, determination in the embodiment) referred to when the engine is determined to be in an idling operation state by the mode determination means. A map 53a), wherein the determination map increases an idle speed of the engine when the battery voltage falls below a first set voltage, and the second set voltage is lower than the first set voltage. It is defined that the power supply to the electric load is stopped when the value falls below.
  With this configuration, when the battery voltage is lower than the first set voltage when the engine is determined to be in the idling operation state, the engine idle speed is increased, so that the amount of power generated by the motor is increased. Can compensate for the lack of power. Furthermore, since the power supply to the electric load is stopped when the battery voltage falls below the second set voltage, the load on the battery can be reduced, and all of the electric power generated by the motor can be used for charging the battery. The overdischarge of the battery can be recovered.

The invention according to claim 7 is the invention according to claim 2, wherein the battery protection means is a first determination map (for example, an embodiment) that is referred to when the engine is determined to be stopped by the mode determination means. And a second determination map (for example, the determination map 53a in the embodiment) that is referred to when the engine is determined to be in the idling operation state by the mode determination means. The map instructs to restart the engine when the remaining battery capacity falls below the first set capacity, and the second set capacity is smaller than the first set capacity after the engine restart instruction. Defined to disconnect the contactor when it falls below, the second decision map shows that the remaining battery capacity falls below the first set capacity The idle speed of the engine is increased, and the power supply to the electric load is stopped when the remaining battery capacity falls below a second set capacity smaller than the first set capacity, and the mode Switching between the first determination map and the second determination map in accordance with the determination by the determination means.
With this configuration, when the engine is determined to be stopped, the first determination map is referred to, and when the remaining battery capacity falls below the first set capacity, the engine is instructed to restart. When the engine is restarted , the power generation by the motor can be resumed, and the generated power can be stored in the battery, and when the remaining battery capacity falls below the second set capacity after the engine restart instruction Since the contactor is disconnected, the discharge from the battery can be completely stopped, and the overdischarge of the battery can be prevented from proceeding.
Further, when the engine is determined to be in the idling operation state, the second determination map is referred to. When the remaining battery capacity falls below the first set capacity, the engine idling speed is increased. The power supply to the electric load is stopped when the remaining battery capacity falls below the second set capacity, and the load on the battery can be reduced. All of the electric power generated by the motor can be used for charging the battery, and the overdischarge of the battery can be recovered.

The invention according to claim 8 is the invention according to claim 2, wherein the battery protection means is a first determination map (for example, an embodiment) which is referred to when the engine is determined to be stopped by the mode determination means. And a second determination map (for example, the determination map 53a in the embodiment) that is referred to when the engine is determined to be in the idling operation state by the mode determination means. The map indicates that the engine is restarted when the battery voltage falls below the first set voltage, and the battery voltage falls below the second set voltage that is smaller than the first set voltage after the engine restart instruction . Sometimes defined to disconnect the contactor, the second decision map is when the battery voltage falls below the first set voltage The engine idling speed is increased, and when the battery voltage falls below a second set voltage smaller than the first set voltage, the power supply to the electric load is defined to be stopped, Switching to either the first determination map or the second determination map is performed according to the determination.
With this configuration, when the engine is determined to be stopped, the first determination map is referred to, and when the battery voltage falls below the first set voltage, the engine is instructed to restart. Since the motor is restarted, the power generation by the motor can be resumed, and the generated power can be stored in the battery. When the battery voltage falls below the second set voltage after the engine restart instruction , the contactor is Since the cutting is performed, the discharge from the battery can be completely stopped, and the overdischarge of the battery can be prevented from proceeding.
Further, when the engine is determined to be in the idling operation state, the second determination map is referred to, and when the battery voltage falls below the first set voltage, the engine idle speed is increased, so that the amount of power generated by the motor is reduced. Since the power supply to the electric load is stopped when the battery voltage falls below the second set voltage, the load on the battery can be reduced. All of the generated electric power can be used for charging the battery, and the overdischarge of the battery can be recovered.

The invention according to claim 9 is the invention according to claim 2, wherein the battery protection means is a first determination map (for example, an embodiment) that is referred to when the engine is determined to be stopped by the mode determination means. And a second determination map (for example, the determination map 53a in the embodiment) that is referred to when the engine is determined to be in the idling operation state by the mode determination means. The map indicates that the engine is restarted when the remaining battery capacity falls below the first set capacity or when the battery voltage falls below the first set voltage, and the remaining battery capacity after the engine restart instruction Falls below a second set capacity that is smaller than the first set capacity, or when the battery voltage is less than the first set voltage. Is defined to disconnect the contactor when the battery voltage falls below the first set capacity, or the battery voltage falls below the first set voltage. When the battery remaining capacity falls below a second set capacity smaller than the first set capacity, or the battery voltage is less than the first set voltage. It is defined to stop the power supply to the electric load when the voltage falls below the second set voltage, and either one of the first determination map and the second determination map is determined according to the determination by the mode determination means. It is characterized by switching.
With this configuration, when the engine is determined to be stopped, the first determination map is referred to, and when the remaining battery capacity falls below the first set capacity or the battery voltage is set to the first setting. when below the voltage, since restarting the engine instructs the restart of the engine, to be able to resume power generation by the motor, it is possible to store the generated power in the battery, also, the engine restart When the remaining battery capacity falls below the second set capacity after the instruction , or when the battery voltage falls below the second set voltage, the contactor is disconnected, so that discharging from the battery can be stopped completely. Thus, it is possible to prevent the battery from being overdischarged.
Further, when the engine is determined to be in an idling operation state, the second determination map is referred to, and when the remaining battery capacity falls below the first set capacity or when the battery voltage falls below the first set voltage Increases the idle speed of the engine, so that the amount of power generated by the motor can be increased, and the insufficient power can be compensated, and when the remaining battery capacity falls below the second set capacity, or When the battery voltage falls below the second set voltage, the power supply to the electric load is stopped. Therefore, the load on the battery can be reduced, and all the electric power generated by the motor can be used for charging the battery. Overdischarge can be recovered.

According to a tenth aspect of the present invention, an engine (for example, the engine 1 in the embodiment) that outputs a driving force of a vehicle and a motor (for example, an implementation) that generates an auxiliary driving force that is directly connected to the engine and assists the output of the engine. Motor 2) in the embodiment, and a battery for supplying electric energy to the motor and charging electric energy obtained by operating the motor as a generator when no auxiliary driving force is required (for example, battery 3 in the embodiment) A contactor for intermittently supplying current between the battery and the motor (for example, the main contactor 11 in the embodiment), and the electric load generated by the motor and the electric load (for example, in the embodiment). A hybrid that stops the engine in accordance with predetermined operating conditions. The control method of de vehicle, the engine is judged whether the stop state idling, if the engine has detected the overdischarge of the battery when it is determined to stop state indicates the restart of the engine, In the hybrid vehicle control method, the contactor is disconnected when overdischarge further proceeds after an instruction to restart the engine .
By configuring in this way, when an overdischarge of the battery is detected when it is determined that the engine is stopped, the engine is restarted by instructing the engine to be restarted. The generated power can be stored in the battery. In addition, when the overdischarge further progresses after the engine restart instruction , the contactor is disconnected, so that the discharge from the battery can be completely stopped and the overdischarge of the battery can be prevented from proceeding. .

According to the first aspect of the present invention, when an overdischarge of the battery is detected when it is determined that the engine is in a stopped state, the engine is restarted by instructing the engine to restart. Thus, the generated power can be stored in the battery, and when the overdischarge further proceeds after the engine restart instruction , the contactor is disconnected, so that the discharge from the battery can be completely stopped, and the battery It is possible to prevent the overdischarge from progressing. In other words, according to the overdischarge state of the battery in the engine stop state, by performing “resumption of power generation by restarting the engine” and “complete discharge stop by disconnecting all electric loads connected to the battery” step by step , Battery overdischarge can be prevented.
As a result, it is possible to obtain an effect that it is possible to prevent deterioration of fuel consumption and power performance.

  According to the second aspect of the present invention, when the engine is determined to be in the idling operation state, when the battery overdischarge is detected, the engine idling speed is increased. However, if the overdischarge progresses further, the power supply to the electrical load is stopped, so the load on the battery can be reduced and all the power generated by the motor is used for charging the battery. And overdischarge of the battery can be recovered. In other words, according to the overdischarge state of the battery in the idle operation state, by performing “increase in power generation amount due to increase in idle rotation speed” and “disconnection of electric load by stopping converter for supplying to electrical components” step by step, Battery overdischarge can be prevented.

According to the third aspect of the invention, when the remaining battery capacity falls below the first set capacity when the engine is determined to be stopped, the engine is restarted by instructing the engine to restart. Can be resumed, and the generated power can be stored in the battery. In addition, since the contactor is disconnected when the remaining battery capacity falls below the second set capacity after the engine restart instruction , the discharge from the battery can be completely stopped and the battery overdischarge is prevented from proceeding. can do.

According to the invention of claim 4, when the engine voltage is determined to be stopped and the battery voltage falls below the first set voltage, the engine is restarted by instructing the engine to restart. The power generation can be resumed, and the generated power can be stored in the battery. Further, since the contactor is disconnected when the battery voltage falls below the second set voltage after the engine restart instruction , the discharge from the battery can be completely stopped, and the battery overdischarge is prevented from proceeding. be able to.

According to the fifth aspect of the invention, when the remaining battery capacity falls below the first set capacity when the engine is determined to be in the idling operation state, the engine idle speed is increased. It can be increased and the power shortage can be compensated. Furthermore, since the power supply to the electric load is stopped when the remaining battery capacity falls below the second set capacity, the load on the battery can be reduced, and all the electric power generated by the motor can be used for charging the battery. The battery can be recovered from overdischarge.

According to the sixth aspect of the present invention, when the battery voltage falls below the first set voltage when the engine is determined to be in the idling operation state, the engine idling speed is increased, so the amount of power generated by the motor is increased. It is possible to make up for the shortage of power. Furthermore, since the power supply to the electric load is stopped when the battery voltage falls below the second set voltage, the load on the battery can be reduced, and all of the electric power generated by the motor can be used for charging the battery. The overdischarge of the battery can be recovered.

According to the invention of claim 7, when the engine is determined to be stopped, the first determination map is referred to, and when the remaining battery capacity falls below the first set capacity, the engine is instructed to restart. Since the engine is restarted, the power generation by the motor can be resumed, and the generated power can be stored in the battery. Also, after the engine restart instruction, the remaining battery capacity falls below the second set capacity. In this case, the contactor is disconnected, so that the discharge from the battery can be stopped completely and the battery overdischarge can be prevented from proceeding.
Further, when the engine is determined to be in the idling operation state, the second determination map is referred to. When the remaining battery capacity falls below the first set capacity, the engine idling speed is increased. The power supply to the electric load is stopped when the remaining battery capacity falls below the second set capacity, and the load on the battery can be reduced. All of the electric power generated by the motor can be used for charging the battery, and the overdischarge of the battery can be recovered.

According to the invention of claim 8, when the engine is determined to be stopped, the first determination map is referred to, and when the battery voltage falls below the first set voltage, the engine is instructed to restart. Since the engine is restarted, the power generation by the motor can be restarted, and the generated power can be stored in the battery, and when the battery voltage falls below the second set voltage after the engine restart instruction Since the contactor is disconnected, the discharge from the battery can be completely stopped, and the overdischarge of the battery can be prevented from proceeding.
Further, when the engine is determined to be in the idling operation state, the second determination map is referred to, and when the battery voltage falls below the first set voltage, the engine idle speed is increased, so that the amount of power generated by the motor is reduced. Since the power supply to the electric load is stopped when the battery voltage falls below the second set voltage, the load on the battery can be reduced. All of the generated electric power can be used for charging the battery, and the overdischarge of the battery can be recovered.

According to the ninth aspect of the present invention, when the engine is determined to be in the stopped state, the first determination map is referred to, and when the remaining battery capacity falls below the first set capacity or the battery voltage is the first when below the set voltage, because the engine is restarted by instructing restart of the engine, to be able to resume power generation by the motor, it is possible to store the generated power in the battery, also the engine When the remaining battery capacity falls below the second set capacity after the restart instruction , or when the battery voltage falls below the second set voltage, the contactor is disconnected, so that discharging from the battery is completely stopped. Thus, it is possible to prevent the battery from being over-discharged.
Further, when the engine is determined to be in an idling operation state, the second determination map is referred to, and when the remaining battery capacity falls below the first set capacity or when the battery voltage falls below the first set voltage Increases the idle speed of the engine, so that the amount of power generated by the motor can be increased, and the insufficient power can be compensated, and when the remaining battery capacity falls below the second set capacity, or When the battery voltage falls below the second set voltage, the power supply to the electric load is stopped. Therefore, the load on the battery can be reduced, and all the electric power generated by the motor can be used for charging the battery. Overdischarge can be recovered.

According to the tenth aspect of the present invention, when an overdischarge of the battery is detected when it is determined that the engine is stopped, the engine is restarted by instructing the engine to restart. Thus, the generated power can be stored in the battery, and if the overdischarge further proceeds after the engine restart instruction , the contactor is disconnected, so that the discharge from the battery can be stopped completely, It is possible to prevent the battery from being over-discharged. In other words, according to the overdischarge state of the battery in the engine stop state, by performing “resumption of power generation by restarting the engine” and “complete discharge stop by disconnecting all electric loads connected to the battery” step by step , Battery overdischarge can be prevented.
As a result, it is possible to obtain an effect that it is possible to prevent deterioration of fuel consumption and power performance.

Hereinafter, a control apparatus and a control method for a hybrid vehicle according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an overall configuration of a parallel hybrid vehicle which is a kind of hybrid vehicle according to an embodiment of the present invention. In this figure, reference numeral 1 denotes an engine that operates with fuel combustion energy, and reference numeral 2 denotes a motor that is used in combination with the engine and operates with electric energy. The driving forces of both the engine 1 and the motor 2 are transmitted to driving wheels (not shown) via a transmission (not shown) made up of an automatic transmission or a manual transmission. Further, when the hybrid vehicle is decelerated, the driving force is transmitted from the driving wheels to the motor 2, and the motor 2 functions as a generator and collects the kinetic energy of the vehicle body as electric energy.

  Reference numeral 3 denotes a battery that supplies electric power to the motor 2 and charges electric energy obtained by operating the motor as a generator when no driving force is required. Here, for example, the battery 3 is configured as a high voltage battery by connecting a plurality of cells in series as a unit and further connecting a plurality of modules in series. Here, it is assumed that the battery 3 can obtain a voltage of 144 [V] by connecting 120 batteries of 1.2 [V] in series. A temperature sensor 19 is attached to the module constituting the battery 3.

  Reference numeral 4 denotes an engine control device that monitors engine speed, vehicle speed, and the like at predetermined intervals, and determines operation modes such as motor regeneration, assist, and deceleration from these results. At the same time, the engine control device 4 determines the assist / regeneration amount corresponding to the operation mode described above, and outputs information on the operation mode and the assist / regeneration amount to the motor control device 5. When receiving the information as described above from the engine control device 4, the motor control device 5 controls the power drive unit 7 that drives / regenerates the motor 2 in accordance with this instruction.

Reference numeral 6 denotes a battery control device, which calculates the remaining battery capacity of the battery 3. In the following description, the remaining battery capacity is expressed using a percentage as a ratio to the fully charged state of the battery 3. Further, the battery control device 6 also controls the cooling fan 18 installed in the battery box that houses the battery 3 so that the temperature of the battery 3 is equal to or lower than a predetermined value in order to protect the battery 3.
The engine control device 4, the motor control device 5, and the battery control device 6 are constituted by a CPU (Central Processing Unit) and a memory, and realize the functions by executing a program for realizing the functions of the control device. .

  Reference numeral 7 denotes a power drive unit, which is composed of two switching elements connected in series and connected in parallel. The switching element in the power drive unit 7 is turned on and off by the motor control device 5, whereby the high-voltage DC component supplied from the battery 3 to the power drive unit 7 is supplied to the motor 2 via the three-phase line. The

  Reference numeral 9 denotes a 12-volt battery for driving various auxiliary machines, and the 12V battery 9 is connected to the battery 3 via the converter 8. Converter 8 steps down the voltage from battery 3 and supplies it to 12V battery 9. Reference numeral 10 denotes a precharge contactor, and reference numeral 11 denotes a main contactor. The battery 3 and the power drive unit 7 are connected via these contactors. The precharge contactor 10 and the main contactor 11 are on / off controlled by the motor control device 5.

  Reference numeral 12 is a sensor for detecting the position and the rotational speed of the motor 2, and reference numeral 13 is a current sensor for detecting a current flowing in the three-phase line. The detection values of these sensors 12 and 13 are input to the motor control device 5.

Reference numeral 14 is a voltage sensor that detects the voltage of the input portion of the power drive unit 7, and reference numeral 15 is a current sensor that detects the current input to the power drive unit 7. Reference numeral 16 denotes a voltage sensor that detects the voltage on the battery 3 side. The voltage value and current value detected by the voltage sensors 14 and 16 and the current sensor 15 are input to the motor control device 5.
Reference numeral 17 denotes a current sensor on the battery 3 side that detects a current flowing on the battery 3 side via the contactor, and the detected current value is input to the battery control device 6.

  As described above, the sensors 14 to 16 detect the voltage and current on the battery 3 side via the contactors 10 and 11 and the voltage and current on the power drive unit 7 side via the contactor. Further, the current detected by the current sensor 15 is a value obtained by subtracting the current flowing through the converter 8.

Next, the operation of each control device of the hybrid vehicle having the above-described configuration will be briefly described.
First, the battery control device 6 calculates the remaining battery capacity based on values such as input / output current, voltage, and temperature on the battery 3 side, and outputs the value to the motor control device 5. The motor control device 5 outputs the received remaining battery capacity to the engine control device 4.
The engine control device 5 determines the operation mode (assist, regeneration, start, deceleration, idle, etc.) and the required power in the motor 2 based on the remaining battery capacity, engine speed, throttle opening, engine torque, actual motor torque, etc. Then, the operation mode and the required power are output to the motor control device 5.

  When the motor control device 5 receives the operation mode and the required power from the engine control device 4, at the time of assist and deceleration, the power on the input side of the power drive unit 7 (the voltage sensor 14 and current sensor 15 side in FIG. 1) Feedback control is performed so that the required power received from the engine control device 5 is obtained. On the other hand, the motor control device 5 performs feedback control so that the power value of the battery 3 (on the side of the voltage sensor 16 and the current sensor 17 in FIG. 1) becomes the required power during cruise. When the electric power is calculated in this way, the motor control device 5 controls the power drive unit 7 according to the calculated electric power.

Next, when the motor control device 5 receives the actual power from the power drive unit 7, the motor control device 5 outputs the actual torque converted from the actual power to the engine control device 4.
The engine control device 4, the motor control device 5, and the battery control device 6 control the engine 1, the motor 2, and the battery 3 to drive the hybrid vehicle by performing the above-described processing as needed at predetermined timing.

  Next, the control device will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration of the control device. In FIG. 2, the code | symbol 51 is an overdischarge detection part which detects whether the battery 3 is an overdischarge state from the voltage and remaining capacity of the battery 3. In FIG. Reference numeral 52 denotes a mode discriminating unit that discriminates the current driving mode of the hybrid vehicle based on the mode information output from the engine control device 4. Reference numeral 53a is a determination map in which measures to be taken for the battery 3 are defined in the overdischarged state of the battery 3 in the idle mode. Reference numeral 53b is a determination map in which measures to be taken for the battery 3 are defined in the overdischarged state of the battery 3 in the idle stop mode.

Reference numeral 54 denotes a charge / discharge control unit that takes measures for protecting the battery 3 with reference to the determination maps 53a and 53b. Reference numeral 55 denotes a contactor control unit that performs ON / OFF control of the main contactor 11. Reference numeral 56 denotes a converter control unit that controls start / stop of the converter 8. Reference numeral 57 denotes an engine speed setting unit that instructs the engine control device 4 to increase or restart the idle speed of the engine 1.
The overdischarge detection unit 51, the mode determination unit 52, the determination maps 53a and 53b, the charge / discharge control unit 54, the contactor control unit 55, the converter control unit 56, and the engine speed setting unit 57 shown in FIG. It is provided inside the motor control device 5 shown.

  Next, the operation of the control device shown in FIG. 2 will be described with reference to FIGS. FIG. 3 is a flowchart showing the operation of the mode determination unit 52 shown in FIG. FIG. 4 is a flowchart showing the operation of the overdischarge detection unit 51 shown in FIG. FIG. 5 is a flowchart showing the operation of the charge / discharge control unit 54 shown in FIG. 6 and 7 are explanatory diagrams showing the configuration of the determination maps 53a and 53b shown in FIG.

First, the determination maps 53a and 53b will be described with reference to FIGS.
FIG. 6 is a determination map 53b that is referred to when the operation mode is the idle stop mode, and defines an operation according to the remaining battery capacity or the battery voltage. In this example, it is defined that the engine 1 is restarted when the remaining battery capacity is 20% or the battery voltage falls below 120V. Further, the main contactor 11 is defined to be turned off when the remaining battery capacity is 10% or the battery voltage falls below 108V.

  FIG. 7 is a determination map 53a that is referred to when the operation mode is the idle mode. In the same manner as the determination map 53b, an operation according to the remaining battery capacity or the battery voltage is defined. In this example, it is defined that the idle speed of the engine 1 is increased when the remaining battery capacity is 20% or the battery voltage is lower than 120V. Further, it is defined that the converter 8 is stopped when the remaining battery capacity is 10% or the battery voltage falls below 108V.

Next, with reference to FIG. 3, an operation in which the mode determination unit 52 performs mode determination will be described.
First, the mode determination part 52 reads the mode information output from the engine control apparatus 4 (step S1). The driving mode of the hybrid vehicle includes modes such as assist, regeneration, start, deceleration, idle, and idle stop. The idle mode is a mode when the engine 1 is in idle rotation, and the idle stop mode is the engine 1 by cutting fuel supplied to the engine 1 when a predetermined condition is satisfied when in the idle mode. It is a mode to stop. The engine control device 4 selects any one of these operation modes according to the driving situation of the vehicle, and notifies the motor control device 5 of the selected operation mode. In response to this, the motor control device 5 controls the motor 2 in accordance with the operation mode. Here, the read mode information is the same as the information notified from the engine control device 4 to control the motor 2.

  Next, the mode determining unit 52 determines what the read mode is (step S2). As a result of the determination, if the mode is the idle mode or the idle stop mode, the process proceeds to step S3, and if the operation mode is any other mode, the process returns to step S1.

  If the result of determination in step S2 is idle mode or idle stop mode, the result is notified to the overdischarge detection unit 51 and charge / discharge control unit 54 (step S3). The contents to be notified at this time are notified so that it can be determined whether the mode is the idle mode or the idle stop mode.

  As described above, the mode determination unit 52 only detects the overdischarge detection unit 51 when the rotation speed of the engine 1 is equal to or lower than the idle rotation speed and the power generation amount by the motor 2 is either the idle mode or the idle stop mode. The current operation mode is notified to the charge / discharge control unit 54. Note that the mode determination unit 52 repeatedly executes the operation shown in FIG.

Next, an operation in which the overdischarge detection unit 51 detects an overdischarge state of the battery 3 will be described with reference to FIG.
First, the overdischarge detection unit 51 reads the current operation mode output from the mode determination unit 52 (step S11). The operation mode read here is an idle mode or an idle stop mode because the output of the mode determination unit 52 is read.

  Next, the overdischarge detection unit 51 determines what the read operation mode is (step S12). If the result of this determination is the idle mode, the map used for determination is switched to a determination map 53a corresponding to the idle mode (step S13). On the other hand, if it is the idle stop mode, the map used for determination is switched to the determination map 53b corresponding to the idle stop mode (step S14).

  Next, the overdischarge detection unit 51 reads the voltage of the battery 3 and the remaining battery capacity notified from the battery control device 6 (step S15). As the voltage of the battery 3, the output of the voltage sensor 16 is used.

  Next, the overdischarge detection unit 51 detects the overdischarge state of the battery 3 from the determination map 53a or 53b that is currently switched to any one and the read battery voltage and remaining battery capacity (step S16). ). Whether the battery 3 is overdischarged is determined by determining whether the remaining battery capacity notified from the battery control device 6 or the voltage value detected by the voltage sensor 16 is a predetermined value (for example, the remaining battery capacity is 20% and the battery voltage is When the voltage is lower than 120V), it is determined that the battery is in an overdischarged state.

  As a result of the detection in step S16, it is determined whether or not the battery 3 is in an overdischarged state (step S17). If the result of this determination is that there is no overdischarge, processing returns to step S11 and the above-described processing is repeated.

  As a result of the determination in step S17, when the battery 3 is in an overdischarged state, the overdischarge detecting unit 51 notifies the charge / discharge control unit 54 of the overdischarged state of the battery 3 (step S18). The content notified here is the current remaining battery capacity, which is a value of 20 to 0%. Further, even when the overdischarge is detected by the battery voltage, the battery remaining capacity corresponding to the battery voltage is replaced and notified.

  As described above, the overdischarge detection unit 51 determines whether the current operation mode is the idle mode or the idle stop mode based on the determination map 53a referred to in the idle mode and the determination map 53b referred to in the idle stop mode. In response to this determination map, the overdischarge state of the battery 3 is detected, and the detected state is notified to the charge / discharge control unit 54. The overdischarge detection unit 51 repeatedly performs the operation shown in FIG.

Next, with reference to FIG. 5, the operation in which the charge / discharge control unit 54 protects the battery 3 will be described.
First, the charge / discharge control unit 54 reads the overdischarge state output from the overdischarge detection unit 51 (step S21). Subsequently, the charge / discharge control unit 54 determines whether or not the read content is a notification indicating that it is in an overdischarge state (step S22). As a result of this determination, if the content does not indicate the overdischarge state, the charge / discharge control unit 54 returns to step S21 and waits until there is a notification indicating the overdischarge state.

  Next, when the content notified from the overdischarge detection unit 51 is a content indicating an overdischarge state, the charge / discharge control unit 54 reads the current mode output from the mode determination unit 52. Subsequently, the charge / discharge control unit 54 switches the determination map 53a or the determination map 53b according to the read operation mode (steps S24, S25, S26).

  Next, the charge / discharge control unit 54 refers to the determination map 53a or 53b switched in step S25 or S26 and takes measures for battery protection according to the overdischarge state (step S27). The measures taken for the battery 3 differ depending on the current operation mode. In the idle stop mode, when the remaining battery capacity is 20% or less, the power generation by the motor 2 is restarted by restarting the engine 1. This is performed when the charge / discharge control unit 54 instructs the engine speed setting unit 57 to restart the engine. Upon receiving this instruction, the engine speed setting unit 57 sets the idle speed and notifies the engine control device 4 of the engine restart. As a result, the power generation by the motor 2 is resumed, so that the electric power generated here can be stored in the battery 3.

  However, the engine 1 cannot be restarted unless the conditions for ensuring safety at the time of engine restart, such as the transmission being neutral and the clutch being disconnected, are not met, so the clutch remains connected by the driver. The engine 1 cannot be restarted, for example. Accordingly, when the engine 1 cannot be restarted even though the engine restart is instructed and the remaining battery capacity becomes 10% or less, the main contactor 11 is turned off to discharge the battery 3. Stop completely. This is performed by the charge / discharge control unit 54 giving an instruction to the contactor control unit 55 to turn off the main contactor 11. Upon receiving this instruction, the contactor control unit 55 outputs a signal for turning off the main contactor 11, thereby turning off the main contactor 11. As a result, the discharge from the battery 3 is completely stopped, so that further overdischarge of the battery 3 can be prevented.

  As described above, “resumption of power generation by restarting the engine” and “complete discharge stop by disconnecting all electric loads connected to the battery” are performed step by step as the remaining battery capacity in the idle stop mode decreases. Thus, overdischarge of the battery 3 can be prevented. When the remaining battery capacity is recovered, “contactor ON” and “idle stop” are performed step by step.

  On the other hand, in the idle mode, when the remaining battery capacity is 20% or less, the motor power generation amount is increased by increasing the idle speed. This is performed by the charge / discharge control unit 54 instructing the engine speed setting unit 57 to increase the idle speed. In response to this instruction, the engine speed setting unit 57 sets the idle speed and notifies the engine controller 4 of the idle speed. This makes up for the lack of power.

  Further, when the remaining battery capacity further decreases to 10% or less, the electric load of the battery 3 is disconnected by further stopping the converter 8 in addition to the increase in the idle speed. This is performed by the charge / discharge control unit 54 giving an instruction to stop the converter 8 to the converter control unit 56. In response to this instruction, the converter control unit 56 outputs a signal to stop the converter 8, thereby stopping the converter 8. While the converter 8 is stopped, the supply of electric power to the electrical components is stopped. During this period, the necessary electric power is supplied from the 12V battery 9. Thereby, the load of the battery 3 can be reduced. However, since the main contactor 11 is in the ON state, the electric power generated by the motor 2 when the engine 1 is idling can be stored in the battery 3.

In this way, by performing step-by-step "increase in power generation due to increase in idle rotation speed" and "disconnection of electric load by stopping converter for supplying electrical components" as the remaining battery capacity in idle mode decreases. The overdischarge of the battery 3 can be prevented. When the remaining battery capacity is recovered, "converter start" and "idle rotation speed initialization" are performed step by step.
The charge / discharge control unit 54 repeatedly performs the operation shown in FIG.

It is a block diagram which shows the structure of the control apparatus of a hybrid vehicle. It is a block diagram which shows the structure of a control apparatus. 3 is a flowchart illustrating an operation of a mode determination unit 52 illustrated in FIG. It is a flowchart which shows operation | movement of the overdischarge detection part 51 shown in FIG. It is a flowchart which shows operation | movement of the charging / discharging control part 54 shown in FIG. It is explanatory drawing which shows the structure of the determination map 53a shown in FIG. It is explanatory drawing which shows the structure of the determination map 53b shown in FIG.

Explanation of symbols

1 ... Engine,
2 ... Motor,
3 ... Battery,
4 ... Engine control device,
5 ... Motor control device,
8 ... Converter,
11 ... Main contactor,
51 ... Overdischarge detector,
52... Mode discrimination unit,
53a, 53b ... judgment map,
54... Charge / discharge control unit,
55 ... contactor control unit,
56. Converter control unit,
57... Engine speed setting unit.

Claims (10)

An engine that outputs the driving force of the vehicle;
A motor that is directly connected to the engine and generates auxiliary driving force to assist the output of the engine;
A battery for supplying electric power to the motor and charging electric energy obtained by operating the motor as a generator when no auxiliary driving force is required;
A contactor for intermittently supplying a current between the battery and the motor;
An electric load supplied by the power generated by the motor and the battery;
Engine stop means for stopping the engine in accordance with predetermined operating conditions;
Mode discrimination means for discriminating whether the engine is in an idling operation state or a stop state;
If the battery is detected to be over-discharged when the engine is determined to be stopped by the mode determination means, the engine is instructed to restart . Battery protection means for cutting the contactor;
A control apparatus for a hybrid vehicle, comprising:   The battery protection means increases the idle speed of the engine when the engine is determined to be in an idling operation state by the mode determination means, and further increases the idle rotation speed of the engine. The hybrid vehicle control device according to claim 1, wherein power supply to the electric load is stopped. The battery protection means includes a determination map that is referred to when the engine is determined to be stopped by the mode determination means.
The determination map gives an instruction to restart the engine when the remaining battery capacity falls below a first set capacity, and the second setting is smaller than the first set capacity after the engine restart instruction. 2. The control device for a hybrid vehicle according to claim 1, wherein the control device is defined so as to disconnect the contactor when the capacity is reduced. The battery protection means includes a determination map that is referred to when the engine is determined to be stopped by the mode determination means.
The determination map instructs the engine to be restarted when the battery voltage falls below the first set voltage, and after the engine restart instruction, the battery voltage is set to a second set voltage that is lower than the first set voltage. 2. The control device for a hybrid vehicle according to claim 1, wherein the control device is defined so as to cut the contactor when it falls below. The battery protection unit includes a determination map that is referred to when the engine is determined to be in an idling operation state by the mode determination unit.
The determination map increases the idle speed of the engine when the remaining battery capacity falls below a first set capacity, and when the remaining battery capacity falls below a second set capacity that is smaller than the first set capacity. The hybrid vehicle control device according to claim 2, wherein the power supply to the electric load is defined to be stopped. The battery protection unit includes a determination map that is referred to when the engine is determined to be in an idling operation state by the mode determination unit.
The determination map increases the idle speed of the engine when the battery voltage falls below a first set voltage, and when the battery voltage falls below a second set voltage lower than the first set voltage, The hybrid vehicle control device according to claim 2, wherein the control device is defined to stop power supply to the electric load. The battery protection means is referred to when a first determination map is referred to when the engine is determined to be stopped by the mode determination means, and when the engine is determined to be in an idling operation state by the mode determination means. A second determination map,
The first determination map instructs the restart of the engine when the remaining battery capacity falls below the first set capacity, and the remaining battery capacity is smaller than the first set capacity after the engine restart instruction . Defined to disconnect the contactor when below the set capacity of 2,
The second determination map increases the idle speed of the engine when the remaining battery capacity falls below the first set capacity, and sets a second set capacity that is smaller than the first set capacity. Defined to stop power supply to the electrical load when
3. The control apparatus for a hybrid vehicle according to claim 2, wherein switching is made between the first determination map and the second determination map in accordance with determination by the mode determination means. The battery protection means is referred to when a first determination map is referred to when the engine is determined to be stopped by the mode determination means, and when the engine is determined to be in an idling operation state by the mode determination means. A second determination map,
The first determination map instructs the engine to be restarted when the battery voltage falls below the first set voltage, and after the engine restart instruction, the battery voltage is smaller than the first set voltage. Defined to disconnect the contactor when below a set voltage,
The second determination map increases the idle speed of the engine when the battery voltage falls below the first set voltage, and the battery voltage falls below the second set voltage that is smaller than the first set voltage. Sometimes defined to stop power supply to the electrical load,
3. The control apparatus for a hybrid vehicle according to claim 2, wherein switching is made between the first determination map and the second determination map in accordance with determination by the mode determination means. The battery protection means is referred to when a first determination map is referred to when the engine is determined to be stopped by the mode determination means, and when the engine is determined to be in an idling operation state by the mode determination means. A second determination map,
The first determination map instructs the engine restart when the remaining battery capacity falls below the first set capacity, or when the battery voltage falls below the first set voltage , When the battery remaining capacity falls below a second set capacity smaller than the first set capacity after the instruction , or when the battery voltage falls below a second set voltage smaller than the first set voltage, the contactor is Defined to disconnect,
When the remaining battery capacity falls below the first set capacity, or when the battery voltage falls below the first set voltage, the second determination map increases the idle speed of the engine to increase the remaining battery capacity. Power supply to the electrical load is stopped when the battery voltage falls below a second set capacity that is smaller than the first set capacity or when the battery voltage falls below a second set voltage that is less than the first set voltage Defined as
3. The control apparatus for a hybrid vehicle according to claim 2, wherein switching is made between the first determination map and the second determination map in accordance with determination by the mode determination means. An engine that outputs a driving force of a vehicle, a motor that is directly connected to the engine and generates an auxiliary driving force that assists the output of the engine, and that supplies electric power to the motor and does not require the auxiliary driving force. A battery for charging electrical energy obtained by operating as a generator; a contactor for intermittently supplying current between the battery and the motor; and power generated by the motor and an electric load supplied by the battery And a hybrid vehicle control method for stopping the engine according to a predetermined operating condition.
It is determined whether the engine is in an idling operation state or a stopped state, and when the battery is detected to be over-discharged when the engine is determined to be in a stopped state , the engine is restarted. A control method for a hybrid vehicle, characterized in that the contactor is disconnected when overdischarge progresses.

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