JP2009160978A - Internal-combustion engine control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal-combustion engine control device for improving both the function of a heater, using heat of cooling water for cooling an internal combustion engine, and improvement in the fuel economy of the internal-combustion engine. <P>SOLUTION: The internal-combustion engine control device of a vehicle traveling by power from a motor driven by electric power generated by the power of the internal-combustion engine as a power source includes an operating mode determination unit for determining the operating mode of the internal combustion engine, according to a cooling water temperature and the state of a capacitor, when a heater for supplying a cabin with warm air by using heat of the internal combustion engine coolant is in operation state. When cooling-water temperature is not higher than the threshold, after setting operating conditions for driving the internal combustion engine, the operating mode determining unit always selects, according to a charging state value of the capacitor, a first mode for supplying electric power to the motor from the capacitor by driving the internal combustion engine at a constant rotational speed that becomes minimum of the fuel consuming amount per unit electric power generation or a second mode for supplying electric power to the motor from the capacitor, by controlling the rotational speed of the internal combustion so as to generate, by the power of the internal-combustion engine, only the electric power consumed by an auxiliary machine. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine control device for a vehicle that travels using power from an electric motor (hereinafter referred to as “motor”) that is driven using electric power generated by the power of an internal combustion engine (hereinafter referred to as “engine”).

  A series-type HEV (Hybrid Electrical Vehicle) includes a motor and an engine, and travels using the power of a motor that is driven by a capacitor as a power source. The engine is used only for power generation, and the electric power generated by the power of the engine is charged in a capacitor or supplied to a motor.

  There are two types of engine operation modes: “BSFC (Brake Specific Fuel Consumption) bottom operation” and “output following operation”. The “BSFC bottom operation” is an engine operation mainly performed when the charge rate of the battery is low. The engine at the time of BSFC bottom operation is fixed-point operation at a constant rotational speed that minimizes the amount of fuel consumed per unit power generation amount. The power generation efficiency by the engine at this time is the best. The electric power generated by the BSFC bottom operation is charged in the battery.

  In addition, “output following operation” refers to supplying electric power from a capacitor to a motor, which is obtained from the vehicle speed and the accelerator opening, and is a value required by the driver as electric power supplied to the motor (hereinafter referred to as “driver required value”). Rather, it is the operation of the engine when it is supplied by power generation by the power of the engine. In addition, the electric power generated at this time is not charged in the battery but is consumed by the motor. The engine during the output follow-up operation is operated at the number of revolutions necessary to supply the power required by the driver. That is, if the driver request value changes, the engine speed also changes. As described above, since the fixed point operation is not performed at the constant rotational speed with the best fuel consumption during the output follow-up operation, the fuel consumption is worse than that during the BSFC bottom operation.

  In the series-type HEV, a heater for vehicle compartment heating uses the heat of engine cooling water. For this reason, when the heater is used in a state where the coolant temperature of the engine cooling water is low because the engine is not warmed up, even if the vehicle can run only with the power of the motor driven by the electric power from the battery Drive the engine to raise the engine coolant water temperature. At this time, if the engine performs the BSFC bottom operation, the electric power generated by the engine power continues to be charged in the battery, which may cause the battery to be overcharged. For this reason, when the heater is used in a state where the coolant temperature of the engine cooling water is low, the engine is output following operation.

  In the heating device for a hybrid vehicle described in Patent Document 1, an engine cooling path for circulating an engine coolant by connecting an engine and an engine radiator in series, a high-power unit including an electric motor, and a high-power radiator Are connected in series to circulate the high-power coolant, and a heater unit is connected in parallel to the engine and the high-power system unit, so that the engine coolant is below a certain temperature. If the strong electric coolant is above a certain temperature, the strong electric coolant is supplied to the heater unit. However, when both the engine coolant and the high-power coolant are below the predetermined temperature, it is necessary to drive the engine until the temperature of the high-power coolant reaches the predetermined temperature. For this reason, when the heating device of Patent Document 1 is applied to a series-type hybrid vehicle, the engine is output following operation under the above conditions.

JP 2006-51852 A

  As described above, even if it is not necessary to start the engine in terms of running conditions, the engine is output following operation when the temperature of the engine coolant is low when the heater is used. However, as described above, the fuel consumption during the output following operation is worse than that during the BSFC bottom operation. For this reason, it cannot be said that the fuel consumption at the start of the above-described vehicle peter use is good.

  An object of the present invention is to provide an internal combustion engine control device that achieves both the function of a heating device that uses the heat of cooling water for cooling an internal combustion engine and the improvement of fuel consumption of the internal combustion engine.

  In order to solve the above problems and achieve the object, an internal combustion engine control apparatus according to a first aspect of the present invention uses electric power generated by the power of an internal combustion engine (for example, the engine 107 in the embodiment). An internal combustion engine control apparatus for a vehicle that travels by power from an electric motor (for example, a motor 105 in the embodiment) that is driven as a source, using the heat of cooling water for cooling the internal combustion engine When a heating device (for example, the heater 119 in the embodiment) for supplying warm air into the interior of the engine is in an operating state, a battery that charges the power generated by the temperature of the cooling water and the power of the internal combustion engine (for example, An operation mode determination unit (for example, an engine operation mode determination unit 203 in the embodiment) that determines the operation mode of the internal combustion engine according to the state of the battery 101) in the embodiment. If the temperature of the cooling water is equal to or lower than a first threshold value, the operation mode determination unit always sets an operation condition for driving the internal combustion engine, and then determines the unit according to the charge state value of the battery. The internal combustion engine is driven at a predetermined constant rotational speed that minimizes the amount of fuel consumed per amount of generated power, and the electric power is supplied to the electric motor from the first mode performed by the battery and the power of the internal combustion engine. In the second mode, the rotational speed of the internal combustion engine is controlled so that only the electric power consumed by the auxiliary machine used in the vehicle including the heating device is generated, and the electric power is supplied to the electric motor from the battery. One of them is selected.

  Furthermore, in the internal combustion engine control apparatus according to claim 2, the operation mode determination unit selects the first mode if the charge state value of the capacitor is smaller than a predetermined value, and the charge state value of the capacitor If the value is equal to or greater than the predetermined value, the second mode is selected.

  Furthermore, in the internal combustion engine control apparatus according to the third aspect of the invention, the operation mode determination unit is configured to provide a second temperature of the cooling water lower than the first threshold value regardless of a state of charge value of the battery. The second mode is selected if it is equal to or less than a threshold value.

  Furthermore, in the internal combustion engine control apparatus according to claim 4, the operation mode determination unit is configured to perform the second mode if the temperature of the battery is equal to or lower than a threshold value regardless of the charge state value of the battery. It is characterized by selecting.

  Furthermore, in the internal combustion engine control apparatus according to claim 5, the operation mode determination unit sets the second mode if the temperature of the battery is equal to or lower than a threshold value regardless of the temperature of the cooling water. It is characterized by selection.

  Furthermore, in the internal combustion engine control device according to the sixth aspect of the present invention, a request for deriving a driver request value required by the driver of the vehicle as electric power to be supplied to the electric motor based on vehicle speed information and driver operation information of the vehicle. An output derivation unit (for example, the required output calculation unit 201 in the embodiment), and the operation mode determination unit is a sum of a maximum power value that can be output by the battery and a power value that can be output in the first mode. When the driver request value is larger than the temperature of the cooling water and the charge state value of the battery, the power to generate the difference between the driver request value and the maximum power value that can be output from the battery. A third mode is selected in which the internal combustion engine is driven at a rotational speed higher than a predetermined constant rotational speed.

  Furthermore, in the internal combustion engine control apparatus according to claim 7, when the operation mode determination unit selects the second mode, when the charge state value of the battery is different from a target value, the auxiliary machine The number of revolutions of the internal combustion engine is controlled so that the sum of the electric power consumed by the electric power and the electric power that compensates for the difference between the charge state value and the target value is generated.

  Furthermore, in the internal combustion engine control device according to the eighth aspect of the present invention, a request for deriving a driver request value required by the driver of the vehicle as electric power to be supplied to the electric motor based on vehicle speed information and driver operation information of the vehicle. An output deriving unit (for example, the required output calculation unit 201 in the embodiment), and when the operation mode determination unit selects the second mode, the power consumed by the auxiliary device and the driver request The number of revolutions of the internal combustion engine is controlled so that a sum with the electric power indicated by the value is generated, and the electric power generated by the power of the internal combustion engine is supplied to the electric motor.

  Further, in the internal combustion engine control apparatus according to claim 9, when the operation mode determination unit selects the second mode, when the charge state value of the battery is different from a target value, the auxiliary machine The rotational speed of the internal combustion engine is controlled so that the sum of the power consumed by the driver, the power indicated by the driver request value, and the power that compensates for the difference between the charge state value and the target value is generated. It is said.

  According to the internal combustion engine control device of any one of claims 1 to 9, after the operating condition for always driving the internal combustion engine is set if the temperature of the cooling water is equal to or lower than the first threshold value, the capacitor A first mode in which the internal combustion engine is driven at a predetermined constant rotational speed that minimizes the amount of fuel consumed per unit generated electric power according to the state of charge of the battery, and power is supplied to the motor from the capacitor, and the internal combustion engine In the second mode, the rotational speed of the internal combustion engine is controlled so that only the electric power consumed by the auxiliary machine used in the vehicle including the heating device is generated by the engine power, and the electric power is supplied to the electric motor from the battery. Either one is selected. The first mode is a fixed point operation with the best fuel efficiency, and the second mode is a low output operation. Both modes can be said to be driving with good fuel consumption because they are continuously driven without significant changes in the rotational speed. Therefore, even when the internal combustion engine is driven in order to make the heating device function, an operation with good fuel consumption can be performed. As a result, the function of the heating device and the improvement of the fuel consumption of the internal combustion engine are compatible.

  According to the internal combustion engine control apparatus of the second aspect of the invention, the first mode is selected if the charge state value of the battery is smaller than a predetermined value, and the second mode is selected if the charge state value of the battery is greater than or equal to the predetermined value. The mode is selected. If the internal combustion engine is continuously driven in the first mode when the charge state value of the capacitor is high, the capacitor immediately enters a fully charged state, and if the first mode is continued thereafter, the capacitor may be overcharged. is there. However, since the battery is not charged in the second mode, overcharging of the battery can be prevented.

  According to the internal combustion engine control apparatus of the third aspect of the invention, the second mode is selected if the temperature of the cooling water is equal to or lower than the second threshold value. If the internal combustion engine that has not been warmed up is operated in the first mode and operated at a high speed, the emission may be deteriorated. However, since the rotational speed of the internal combustion engine is low in the second mode, deterioration of emissions can be prevented.

  According to the internal combustion engine control apparatus of the fourth or fifth aspect of the invention, the second mode is selected if the temperature of the battery is equal to or lower than the threshold value. When the temperature of the capacitor is low, the substantial capacity of the capacitor decreases. At this time, if the internal combustion engine is continuously operated in the first mode, the battery is immediately charged, and if the first mode is continued thereafter, the battery may be overcharged. However, since the battery is not charged in the second mode, overcharging of the battery can be prevented.

  According to the internal combustion engine control apparatus of the sixth aspect of the present invention, when there is an output request from the driver, it can be met.

  According to the internal combustion engine control apparatus of the seventh aspect of the present invention, it is possible to prevent overdischarge of the battery and deterioration of emission due to driving of the electric motor. In addition, the lower limit of the charge state value of the battery that decreases as the electric motor is driven can be set to an optimum target value for the battery.

  According to the internal combustion engine control apparatus of the eighth aspect of the present invention, it is possible to prevent overdischarge of the capacitor and deterioration of emission due to driving of the electric motor.

  According to the internal combustion engine control apparatus of the ninth aspect of the invention, the state of charge value of the battery can be set to an optimum target value for the battery.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In an embodiment described below, an internal combustion engine control device according to the present invention is mounted on a series-type HEV (Hybrid Electrical Vehicle) vehicle.

(First embodiment)
FIG. 1 is a block diagram showing a power system and a power system of a series-type HEV. As shown in FIG. 1, a series-type HEV includes a battery (BATT) 101, an inverter (INV) 103, a motor (TR Mot) 105, an engine (ENG) 107, a generator (GEN) 109, an inverter (INV) 111, battery ECU (BATT ECU) 113, management ECU (MG ECU) 115, engine ECU (ENG ECU) 117, and heater 119 are provided.

  The storage battery 101 has a plurality of storage cells connected in series, and supplies a high voltage of, for example, 100 to 200V. Inverter 103 converts a DC voltage from battery 101 into an AC voltage and supplies a three-phase current to motor 105. In addition, in the inverter 103, an FET (Field Effect Transistor) that controls current supply from the battery 101 to the motor 105 is provided. The gate of this FET is controlled by a gate signal from the management ECU 115. The motor 105 generates power for driving the vehicle. The torque generated by the motor 105 varies depending on the value of the three-phase current supplied via the inverter 103.

  The engine 107 is used only for power generation, and the electric power generated by the power of the engine 107 is charged in the battery 101 or supplied to the motor 105. Generator 109 generates electric power by driving engine 107. Inverter 111 converts the AC voltage generated by generator 109 into a DC voltage. The electric power converted by the inverter 111 is charged in the battery 101 or supplied to the motor 105 through the inverter 103. The motor 105 is usually supplied with power from the battery 101. However, when the driver needs more power than the power that the battery 101 can output, such as when the driver fully opens the accelerator, In addition to the electric power, electric power generated by the power of the engine 107 is also supplied.

  Battery ECU 113 sends information obtained from battery 101 (hereinafter referred to as “battery information”) to management ECU 115. The battery information includes information on the SOC of the battery 101, the temperature of the battery 101 (hereinafter referred to as “battery temperature”), and the maximum power value that can be output by the battery 101 (hereinafter referred to as “battery output limit value”). . The heater 119 supplies warm air for heating to the passenger compartment space using the heat of the engine coolant. The operating state of the heater 119 is monitored by the management ECU 115.

  In addition to the battery information from the battery ECU 113, the management ECU 115 includes vehicle speed information and driver operation information (accelerator opening and brake pedaling force), engine coolant temperature (hereinafter referred to as “engine coolant temperature”) information, and auxiliary load. Power consumption (hereinafter referred to as “auxiliary load power consumption”) information and information indicating the operating state of the heater 119 (hereinafter referred to as “heater operation information”) are input. Auxiliary equipment loads include heaters, ECUs, electric motors for fans for cooling the condenser 101, heat rays used for seat heaters, lamps used for backlights of meters, Peltier elements, air It is a cleaner.

  The management ECU 115 outputs the command values (power generation output command value and engine speed command value) determined based on the input battery information, vehicle speed information, driver operation information, engine cooling water temperature information, and auxiliary machine load power consumption information to the engine ECU 117. Output to. Details of the management ECU 115 will be described later. The engine ECU 117 controls the start and stop of the engine 107 and the engine speed according to the command value output from the management ECU 115.

  FIG. 2 is a block diagram showing an internal configuration of the management ECU 115. As shown in FIG. 2, the management ECU 115 includes a request output calculation unit 201, an engine operation mode determination unit 203, and a command value output unit 205. The request output calculation unit 201 calculates a value (hereinafter referred to as “driver request value”) requested by the driver as electric power to be supplied to the motor 105 based on the vehicle speed, the accelerator opening, and the brake pedal force input to the management ECU 115. Ask. The request output calculation unit 201 may calculate the driver request value by referring to a table in which the vehicle speed, the accelerator opening, the brake pedal effort, and the driver request value correspond to each other, instead of calculating the driver request value.

  The engine operation mode determination unit 203 includes a driver request value calculated by the request output calculation unit 201, the SOC of the battery 101, the battery temperature and the battery output limit value included in the battery information input from the battery ECU 113, and the engine coolant temperature. The operation mode of the engine 107 is determined based on the information and the heater operation information. Command value output unit 205 determines a command value (a power generation output command value and an engine speed command value) based on the operation mode determined by engine operation mode determination unit 203 and outputs the command value to engine ECU 117.

  Hereinafter, the operation mode determination process performed by the engine operation mode determination unit 203 included in the management ECU 115 will be described by dividing the process into three processes (operation condition setting process, BSFC bottom operation availability determination process, and mode switching process).

  First, the operating condition setting process will be described. FIG. 3 is a flowchart showing an operation condition setting process performed by the engine operation mode determination unit 203 included in the management ECU 115. As shown in FIG. 3, the engine operation mode determination unit 203 determines whether the heater 119 is operating based on the heater operation information (step S101). When the heater 119 is not operating, the engine operation mode determination unit 203 sets the operation condition to the “normal operation mode” in which the output follow-up operation or the BSFC bottom operation is performed according to the situation (step S103). In the normal operation mode, the engine 107 is driven as necessary according to the SOC of the battery 101, the driver request value, and the like. On the other hand, when the heater 119 is operating, the engine operation mode determination unit 203 proceeds to step S105.

  In step S105, the engine operation mode determination unit 203 determines whether or not the engine coolant temperature is higher than the first threshold value based on the engine coolant temperature information input to the management ECU 115. When it is determined that the engine coolant temperature is higher than the first threshold value, the engine operation mode determination unit 203 proceeds to step S103 and sets the operation condition to the normal operation mode. In the normal operation mode, the output follow-up operation or the BSFC bottom operation is performed depending on the situation. On the other hand, when it is determined that the engine coolant temperature is equal to or lower than the first threshold value, the engine operation mode determination unit 203 performs “heater operation” in which output follow-up operation, BSFC bottom operation, or auxiliary load power generation operation is performed depending on the situation. Set the operating conditions in “Mode”. In the heater operation mode, the engine 107 is always driven. When the operation condition is set to the heater operation mode, the engine operation mode determination unit 203 performs a BSFC bottom operation availability determination process described below.

  The BSFC bottom operation availability determination process will be described. FIG. 4 is a flowchart showing BSFC bottom operation feasibility determination processing performed by the engine operation mode determination unit 203 included in the management ECU 115. As shown in FIG. 4, the engine operation mode determination unit 203 determines whether or not the engine coolant temperature is higher than the second threshold value based on the engine coolant temperature information (step S201). The second threshold value is lower than the first threshold value used in step S105 in FIG. When it is determined that the engine coolant temperature is equal to or lower than the second threshold value, the engine operation mode determination unit 203 determines not to perform the BSFC bottom operation (step S203). On the other hand, when it is determined that the engine coolant temperature is higher than the second threshold value, the engine operation mode determination unit 203 proceeds to step S205.

  In step S <b> 205, the engine operation mode determination unit 203 determines whether or not the SOC of the battery 101 is smaller than the threshold value based on the battery information input to the management ECU 115. When it is determined that the SOC of the battery 101 is equal to or greater than the threshold value, the engine operation mode determination unit 203 proceeds to step S203 and determines not to perform the BSFC bottom operation. On the other hand, when it is determined that the SOC of the battery 101 is smaller than the threshold value, the engine operation mode determination unit 203 proceeds to step S207.

  In step S207, the engine operation mode determination unit 203 determines whether or not the temperature of the battery 101 (battery temperature) is higher than a threshold value based on the battery information input to the management ECU 115. When it is determined that the battery temperature is equal to or lower than the threshold value, the engine operation mode determination unit 203 proceeds to step S203 and determines not to perform the BSFC bottom operation. On the other hand, when it is determined that the battery temperature is higher than the threshold value, the engine operation mode determination unit 203 determines to perform the BSFC bottom operation (step S209).

  In this way, the engine operation mode determination unit 203 (1) the engine coolant temperature is higher than the second threshold value, (2) the SOC of the battery 101 is lower than the threshold value, and (3) the battery temperature is reduced. When it is determined that the value is larger than the threshold value, it is determined that the BSFC bottom operation is performed. At this time, the engine operation mode determination unit 203 sets the power generation condition to “BSFC bottom operation mode” when the operation condition is set to “heater operation mode”. On the other hand, when the engine operation mode determination unit 203 determines that the BSFC bottom operation is not performed, the engine operation mode determination unit 203 “complements the power generation condition when the operation condition is set to the“ heater operation mode ”. Set to “Load Load Operation Mode”.

  The “auxiliary load power generation operation” is an operation of the engine 107 for generating only the power consumed by the auxiliary load. At this time, all the electric power supplied to the motor 105 is supplied from the battery 101. The electric power generated by the power of the engine 107 that has been operated for auxiliary load generation is supplied to the auxiliary load via a DCDC converter (not shown). The power consumed by the auxiliary load is small compared to the power consumed by the motor. For this reason, the engine 107 that is driven by auxiliary load power generation is driven at a lower rotational speed than during BSFC bottom operation that is driven at a relatively high rotational speed. It should be noted that the electric power consumed by the auxiliary machine load does not frequently change greatly, and therefore the rotational speed of the engine 107 during the auxiliary machine load power generation operation is substantially constant.

  As described above, in the BSFC bottom operation feasibility determination process, it is determined that the auxiliary load power generation operation is performed when the engine coolant temperature is equal to or lower than the second threshold value. The low engine cooling water temperature means that the engine 107 is not warmed up. If the engine 107 that has not been warmed up is operated at a high speed by BSFC bottom operation, the emission may be deteriorated. However, if the auxiliary load power generation operation is performed, since the rotation speed during the auxiliary load power generation operation is low as described above, it is possible to prevent the emission from deteriorating.

  In the BSFC bottom operation feasibility determination process, it is determined that the auxiliary load power generation operation is performed when the SOC of the battery 101 is equal to or greater than the threshold value. If the BSFC bottom operation is continuously performed when the SOC of the battery 101 is high, the battery 101 may be in a fully charged state immediately, and if the BSFC bottom operation is continued thereafter, the battery may be in an overcharged state. However, if the auxiliary load power generation operation is performed, charging of the battery 101 is not performed, and thus overcharging of the battery 101 can be prevented. However, since all the electric power supplied to the motor 105 during the auxiliary load power generation operation is supplied from the battery 101, the SOC of the battery 101 decreases as the motor 105 is driven.

  Further, in the BSFC bottom operation availability determination process, it is determined that the auxiliary load power generation operation is performed when the battery temperature is equal to or lower than the threshold value. When the battery temperature is low, the substantial capacity of the battery 101 decreases. At this time, if the BSFC bottom operation is continuously performed, the battery 101 immediately enters a fully charged state, and if the BSFC bottom operation is continuously performed thereafter, there is a concern that an overcharged state may occur. However, if the auxiliary load power generation operation is performed, charging of the battery 101 is not performed, and thus overcharging of the battery 101 can be prevented.

  Next, the mode switching process will be described. Since the state of the battery 101 and the engine coolant temperature change, the engine operation mode determination unit 203 changes the operation condition and the power generation condition according to the change in the situation. Further, since the driver output value changes depending on the driving state and the driver operation, the engine operation mode determination unit 203 changes the operation condition according to the change of the driver output value.

  FIG. 5 is a flowchart showing a mode switching process performed by the engine operation mode determination unit 203 included in the management ECU 115. As shown in FIG. 5, the engine operation mode determination unit 203 determines that the driver request value output by the request output calculation unit 201 is greater than the sum of the power value obtained when the engine 107 is BSFC bottom-operated and the battery output limit value. It is determined whether it is larger (step S301). When it is determined that the driver request value is larger than the total, the engine operation mode determination unit 203 sets the power generation condition to output follow-up operation regardless of whether the operation condition is set to the normal operation mode or the heater operation mode. Switching (step S303). On the other hand, when it is determined that the driver request value is equal to or less than the total, the engine operation mode determination unit 203 proceeds to step S305.

  In step S305, the engine operation mode determination unit 203 performs the operation condition setting process described above with reference to FIG. 3 to determine whether the operation condition is set to the normal operation mode or the heater operation mode. to decide. When the operation condition is set to the normal operation mode, the engine operation mode determination unit 203 switches the power generation condition to the BSFC bottom operation mode (step S307). On the other hand, when the operation condition is set to the heater operation mode, the engine operation mode determination unit 203 proceeds to step S309.

  In step S309, the engine operation mode determination unit 203 performs the BSFC bottom operation enable / disable determination process described above with reference to FIG. 4 and determines whether to perform the BSFC bottom operation. When the engine operation mode determination unit 203 determines that the BSFC bottom operation is performed, the engine operation mode determination unit 203 proceeds to step S307 and switches the power generation condition to the BSFC bottom operation mode. On the other hand, when the engine operation mode determination unit 203 determines that the BSFC bottom operation is not performed, the engine operation mode determination unit 203 switches the power generation condition to the auxiliary load power generation operation mode (step S311).

  Command value output unit 205 determines a command value (power generation output command value and engine speed command value) based on the operation mode determined by the operation mode determination process performed by engine operation mode determination unit 203 described above, and engine ECU 117. Output to. However, the command value based on the auxiliary load power generation operation mode is determined based on the auxiliary load power consumption information input to the management ECU 115. The command value based on the output follow-up mode is determined based on the driver request value and the battery output limit value calculated by the request output calculation unit 201.

  As described above, in the present embodiment, when the heater 119 is operated in a state where the engine coolant temperature is low, that is, when the operation condition is the heater operation mode, unless a very high output is required by the driver. Depending on the engine coolant temperature and the state of the battery 101, the engine 107 is subjected to BSFC bottom operation or auxiliary load power generation operation. The BSFC bottom operation is a fixed point operation at a constant rotational speed with the best fuel efficiency, and the auxiliary load power generation operation is a low output operation. Since both driving modes are operated continuously without a significant change in the rotational speed, it can be said that the driving is good in fuel efficiency. Therefore, even when the engine 107 is driven to make the heater 119 function, it is possible to perform engine operation with good fuel efficiency.

  FIG. 6 is a graph showing vehicle speed, engine output, and battery output obtained in each running test of the vehicle of the first embodiment and the conventional vehicle. FIG. 6E is a graph showing the engine output of the vehicle according to the first embodiment. In the time zone indicated by reference numeral 301 in FIG. 6E, the operation condition is set to the heater operation mode, and the power generation condition is set to the auxiliary load power generation operation mode. Moreover, in the time slot | zone which the code | symbol 303 shows, an operating condition is set to the operation mode for heaters, and the electric power generation condition is set to the BSFC bottom operation mode. Moreover, in the time slot | zone which the code | symbol 305 shows, an operating condition is set to normal operation mode, and electric power generation conditions are set to BSFC bottom operation mode.

(Second Embodiment)
In the first embodiment, since all the electric power supplied to the motor 105 during the auxiliary load power generation operation is supplied from the capacitor 101, the SOC of the capacitor 101 is driven according to the driving of the motor 105 in the auxiliary load power generation operation mode. descend. However, if the auxiliary load power generation operation continues for a long time, the battery 101 may be overdischarged. Further, when the SOC of the battery 101 decreases to a level that requires charging, it is necessary to increase the rotational speed of the engine 107 for charging even though the warm-up is not completed. However, if the number of revolutions of the engine 107 is increased in a state where the warm-up has not been completed, there is a risk that the emission will deteriorate. Therefore, in the second embodiment, the power generation amount of the engine 107 is controlled so that the SOC of the battery 101 becomes the target value.

  In the auxiliary load power generation operation performed in the first embodiment, only the electric power consumed by the auxiliary load is generated. In the present embodiment, a total electric power is generated for the power consumed by the auxiliary load and the power necessary to compensate for the difference to the target SOC of the battery 101 (hereinafter referred to as “compensation power”). Hereinafter, driving of the engine 107 for performing the power generation is referred to as “auxiliary load SOC compensation power generation operation”. In the auxiliary load SOC compensation power generation operation mode, the command value output unit 205 of the management ECU 115 determines a command value based on the auxiliary load power consumption information input to the management ECU 115, the SOC of the battery 101, and the target SOC. .

  When the SOC of the battery 101 (hereinafter referred to as “actual SOC”) is lower than the target SOC, the command value output unit 205 calculates the difference between the target SOC and the actual SOC, and the power consumed by the auxiliary load and the compensation power A command value including a power generation output command value indicating the sum of the values is output. Command value output unit 205 outputs the command value until there is no difference between the target SOC and the actual SOC. As a result, as indicated by reference numeral 401 in FIG. 7, the actual SOC increases to the target SOC. Thus, since the SOC of the battery 101 can be raised to the optimum target SOC, the overdischarge of the battery 101 and the deterioration of emission due to the driving of the motor 105 can be prevented.

  On the other hand, when the actual SOC is equal to or greater than the target SOC, the command value output unit 205 calculates the difference between the target SOC and the actual SOC. The command value output at this time is the auxiliary load power generation operation mode described in the first embodiment. It is the same as the command value at the time. As a result, as indicated by reference numeral 403 in FIG. 7, the actual SOC decreases to the target SOC. When the actual SOC falls below the target SOC after decreasing to the target SOC, the rotational speed is increased again to the target SOC. For this reason, the lower limit of the SOC of the battery 101 that decreases as the motor 105 is driven can be set to the optimum target SOC for the battery 101.

(Third embodiment)
In the first embodiment, since all the electric power supplied to the motor 105 during the auxiliary load power generation operation is supplied from the capacitor 101, the SOC of the capacitor 101 is driven according to the driving of the motor 105 in the auxiliary load power generation operation mode. descend. However, if the auxiliary load power generation operation continues for a long time, the battery 101 may be overdischarged. Further, when the SOC of the battery 101 decreases to a level that requires charging, it is necessary to increase the rotational speed of the engine 107 for charging even though the warm-up is not completed. However, if the number of revolutions of the engine 107 is increased in a state where the warm-up has not been completed, there is a risk that the emission will deteriorate. Therefore, in the third embodiment, the power generation amount of the engine 107 is controlled so that the power supplied to the motor 105 is also supplied by power generation by driving the engine 107.

  In the auxiliary load power generation operation performed in the first embodiment, only the electric power consumed by the auxiliary load is generated. In the present embodiment, the total power of the power consumed by the auxiliary machine load and the driver request value calculated by the request output calculation unit 201 is generated. Hereinafter, the driving of the engine 107 for performing the power generation is referred to as “auxiliary load driver required power generation operation”. In the auxiliary load driver required power generation operation mode, the command value output unit 205 of the management ECU 115 is based on the auxiliary load power consumption information input to the management ECU 115 and the driver request value output from the request output calculation unit 201. Determine the command value. In the auxiliary load driver required power generation operation mode, the electric power supplied to the motor 105 is not supplied from the battery 101 but is generated by the power of the engine 107.

  Since the battery 101 is not discharged in the auxiliary load driver required power generation operation mode, the SOC of the battery 101 is maintained at the value when the mode is started, as indicated by reference numeral 501 in FIG. As indicated by reference numeral 503 in FIG. 8, when the value at the start of the mode is lower than the predetermined value, the SOC of the battery 101 is increased to the predetermined value as in the second embodiment. May be. Thus, since the SOC of the battery 101 does not decrease, overdischarge of the battery 101 due to driving of the motor 105 and deterioration of emissions can be prevented.

Block diagram showing the power system and power system of a series-type HEV Block diagram showing the internal configuration of the management ECU The flowchart which shows the driving | operation condition setting process which the engine driving mode determination part which management ECU has has The flowchart which shows the BSFC bottom operation permission judgment processing which the engine operation mode determination part which management ECU has performs The flowchart which shows the mode switching process which the engine operation mode determination part which management ECU has performs The graph which shows the vehicle speed, engine output, and battery output which were obtained by each driving test of the vehicle of 1st Embodiment and the conventional vehicle The graph which shows the time change of SOC of a capacitor | condenser when performing auxiliary load SOC compensation power generation driving | operation of 2nd Embodiment The graph which shows the time change of SOC of a capacitor | condenser when performing auxiliary machinery load driver demand power generation operation of 3rd Embodiment

Explanation of symbols

101 Battery (BATT)
103 Inverter (INV)
105 Motor (TR Mot)
107 Engine (ENG)
109 Generator (GEN)
111 Inverter (INV)
113 Battery ECU (BATT ECU)
115 Management ECU (MG ECU)
117 Engine ECU (ENG ECU)
119 Heater 201 Request output calculation unit 203 Engine operation mode determination unit 205 Command value output unit

Claims (9)

An internal combustion engine control device for a vehicle that travels by power from an electric motor that uses electric power generated by the power of the internal combustion engine as a power source,
Electric power generated by the temperature of the cooling water and the power of the internal combustion engine when the heating device that supplies the hot air into the vehicle interior using the heat of the cooling water for cooling the internal combustion engine is in operation An operation mode determination unit that determines the operation mode of the internal combustion engine according to the state of the battery that charges the battery,
The operation mode determination unit
If the temperature of the cooling water is equal to or lower than the first threshold value, after always setting the operating conditions for driving the internal combustion engine,
The internal combustion engine is driven at a predetermined constant rotational speed that minimizes the amount of fuel consumed per unit generated power according to the state of charge of the battery, and power is supplied to the motor from the battery. And controlling the number of revolutions of the internal combustion engine so that only the amount of power consumed by the auxiliary machine used in the vehicle including the heating device is generated by the power of the internal combustion engine and the power of the internal combustion engine, Supply is selected from any one of the second modes performed from the capacitor. The internal combustion engine control device according to claim 1,
The operation mode determination unit selects the first mode if the charge state value of the battery is smaller than a predetermined value, and selects the second mode if the charge state value of the battery is equal to or greater than the predetermined value. An internal combustion engine control device. An internal combustion engine control apparatus according to claim 2,
The operation mode determination unit selects the second mode if the temperature of the cooling water is equal to or lower than a second threshold value that is lower than the first threshold value, regardless of the state of charge value of the battery. An internal combustion engine control device. An internal combustion engine control apparatus according to claim 2,
The operation mode determination unit selects the second mode if the temperature of the battery is equal to or lower than a threshold value, regardless of the charge state value of the battery. An internal combustion engine control device according to claim 3,
The internal combustion engine control device, wherein the operation mode determination unit selects the second mode if the temperature of the battery is equal to or lower than a threshold value, regardless of the temperature of the cooling water. The internal combustion engine control device according to claim 1,
A request output deriving unit for deriving a driver request value requested by the driver of the vehicle as electric power to be supplied to the electric motor based on vehicle speed information and driver operation information of the vehicle;
The operation mode determination unit
When the driver request value is larger than the sum of the maximum power value that can be output by the battery and the power value that can be output in the first mode, regardless of the temperature of the cooling water and the charge state value of the battery. A third mode is selected in which the internal combustion engine is driven at a rotational speed higher than the predetermined constant rotational speed so as to generate electric power that is the difference between the driver required value and the maximum electric power value that can be output by the battery. An internal combustion engine control device. The internal combustion engine control device according to any one of claims 1 to 6,
When the operation mode determination unit selects the second mode, when the charge state value of the battery is different from a target value, the power consumed by the auxiliary machine and the difference between the charge state value and the target value An internal combustion engine control apparatus for controlling the rotational speed of the internal combustion engine so that a sum of the electric power and the power to compensate for the power is generated. The internal combustion engine control device according to any one of claims 1 to 6,
A request output deriving unit for deriving a driver request value requested by the driver of the vehicle as electric power to be supplied to the electric motor based on vehicle speed information and driver operation information of the vehicle;
When the second mode is selected, the operation mode determination unit controls the rotational speed of the internal combustion engine so that the sum of the power consumed by the auxiliary machine and the power indicated by the driver request value is generated. The electric motor is supplied with electric power generated by the power of the internal combustion engine. The internal combustion engine control device according to claim 8,
When the operation mode determination unit selects the second mode, when the charge state value of the battery is different from a target value, the power consumed by the auxiliary device, the power indicated by the driver request value, An internal combustion engine control device that controls the number of revolutions of the internal combustion engine so that a sum of the charge state value and electric power that compensates for a difference between the target values is generated.

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