JP6322417B2 - Voltage fluctuation control device - Google Patents

Description

  The present invention relates to a voltage fluctuation control device and a voltage fluctuation control method for a motor side voltage of a converter in a vehicle including an electric motor driven by power supply from a capacitor via a converter.

  Vehicles such as HEVs (Hybrid Electrical Vehicles) and EVs (Electrical Vehicles) are equipped with electric motors and travel by the driving force of the electric motors according to the driving state of the vehicle and the accelerator operation of the driver. The electric motor is driven by electric power supplied from the battery. Further, when the vehicle decelerates, the electric motor operates as a generator, and the electric power generated by the regenerative energy is charged in the capacitor. The power storage device is provided with a plurality of power storage cells connected in series. Secondary batteries, such as a nickel metal hydride battery and a lithium ion battery, are used for an electrical storage cell. In order to utilize the deterioration of the secondary battery to the minimum, it is necessary to perform control for preventing overcharge and overdischarge of the battery. Therefore, each power limit on the discharge side and the charge side is set in the battery. Note that the allowable power range indicating the range from the discharge-side limit power to the charge-side limit power varies depending on the remaining capacity (SOC: State of Charge) of the capacitor as shown in FIG. 11, and as shown in FIG. It depends on the temperature.

  FIG. 13 is a block diagram showing a configuration of a drive system provided in a vehicle such as HEV or EV. The drive system shown in FIG. 13 includes a capacitor 101, a converter 105, a first inverter (TRC INV) 107, an electric motor (TRC MOT) 109, a generator (GEN MOT) 113, and a second inverter (GEN INV). 115 and a smoothing capacitor C. Note that the first inverter 107 and the second inverter 115 are provided in parallel to the converter 105. Further, the smoothing capacitor C is provided in parallel with the converter 105 between the converter 105 and the first inverter 107 and the second inverter 115.

JP 2010-088167 A

  In the drive system shown in FIG. 13, the difference between the power consumed by the motor 109 as the drive source and the power generated by the generator 113 (unbalanced power difference = power consumption−generated power) is input to and output from the battery 101. The That is, the battery 101 discharges or charges the unbalanced power difference. This unbalanced power difference changes according to a DC voltage equal to the voltage across the smoothing capacitor C (hereinafter referred to as “V2 voltage”). The target value of the V2 voltage is set to a value giving priority to energy efficiency so that the power loss on the first inverter 107 and the motor 109 side and the power loss on the second inverter 115 and the generator 113 side are minimized. Converter 105 is controlled so that the V2 voltage approaches this target value.

  However, when the V2 voltage controlled according to the target value of the V2 voltage giving priority to energy efficiency fluctuates abruptly, the unbalanced power difference may exceed the allowable power range of the battery as shown in FIG. . Charge and discharge of electric power exceeding such limit electric power promotes deterioration of the battery. In particular, when the SOC of the battery is low, or when the temperature of the battery is low or high, the allowable power range of the battery is narrow, so that there is a high possibility that charging / discharging exceeding the limit power of the battery will be performed. However, if the capacity of the battery is increased so that the unbalanced power difference does not exceed the limit power, the system can be prevented from becoming smaller or lighter.

  An object of the present invention is to provide a voltage fluctuation control device and a voltage fluctuation control method capable of suppressing the progress of deterioration of a capacitor due to charge / discharge exceeding the limit power of the capacitor.

In order to solve the above problems and achieve the object, a voltage fluctuation control device according to a first aspect of the present invention includes a capacitor (for example, the capacitor 101 in the embodiment) and a DC voltage output from the capacitor. A converter (for example, the converter 105 in the embodiment) that converts the DC voltage to a different level, and an electric motor (for example, the electric motor 109 in the embodiment) that is driven by power supply from the capacitor via the converter A voltage fluctuation control device (for example, management ECU 123 in the embodiment) in a vehicle including a load, and a target power deriving unit that derives a target power output from the electric motor in accordance with a required driving force for the vehicle (For example, target power calculation unit 153 in the embodiment) and power consumption derivation for deriving power consumption of the electric motor according to the target power (For example, a power consumption calculation unit 155 in the embodiment) and a load side voltage target value setting that sets a target value of the load side voltage of the converter according to the power consumption of the motor derived by the power consumption deriving unit (For example, a V2 voltage target value setting unit 159 in the embodiment) and a generated power deriving unit for deriving generated power by the motor that operates as a generator when the vehicle decelerates , the load side voltage The target value setting unit suppresses the rate of change of the target value of the load side voltage according to the state of the capacitor or the limit power of the capacitor set in advance with respect to the state , and the power consumption deriving unit The target value of the load side voltage of the converter is derived based on the difference between the electric power consumption of the electric motor derived from the above and the generated electric power of the electric motor derived by the generated electric power deriving unit .

Furthermore, in the voltage fluctuation control apparatus according to the second aspect of the present invention, in the voltage fluctuation control apparatus according to the first aspect, the load includes a generator that generates electric power by operating an internal combustion engine, and the generated electric power is derived. The unit derives the electric power generated by the generator according to the required driving force for the vehicle, and the load-side voltage target value setting unit calculates the electric power consumption of the electric motor and the generated electric power derived by the electric power consumption deriving unit. A target value of the load side voltage of the converter is derived based on a difference between the electric power generated by the derivation unit and the electric power generated by the generator.

Furthermore, the voltage fluctuation control device of the invention according to claim 3 is based on a capacitor, a converter that converts a DC voltage output from the capacitor into a DC voltage of a different level, and power supply from the capacitor via the converter. A voltage fluctuation control apparatus for a vehicle including a load including an electric motor to be driven, a target power deriving unit for deriving a target power output from the electric motor according to a required driving force for the vehicle, and a target power A power consumption deriving unit for deriving the power consumption of the motor according to the load, and a load side voltage target value setting for setting a target value of the load side voltage of the converter according to the power consumption of the motor derived by the power consumption deriving unit comprising a part, and when the temperature of the storage battery is within a predetermined temperature range, the load-side voltage target value setting unit includes a target value of the load side voltage of the converter When the difference in value exceeds the change width limit of the load-side voltage according to the temperature of the capacitor, the change in the target value of the load-side voltage is changed to the change width limit around the actual value of the load-side voltage. It is characterized by restraining in.

A voltage fluctuation control apparatus according to a fourth aspect of the present invention is the voltage fluctuation control apparatus according to the third aspect , wherein the load side voltage target value setting unit is set when the temperature of the battery is outside the predetermined temperature range. Is characterized in that a predetermined amount is set as the target value of the load side voltage.

A voltage fluctuation control apparatus according to a fifth aspect of the present invention is the voltage fluctuation control apparatus according to the third aspect, wherein when the temperature of the capacitor is outside the predetermined temperature range, the drive of the converter is suspended. It is characterized by control.

A voltage fluctuation control apparatus according to a sixth aspect of the present invention is the voltage fluctuation control apparatus according to the third aspect , wherein the load side voltage target value setting unit is set when the temperature of the battery is outside the predetermined temperature range. Holds the previous target value as the target value of the load side voltage.

According to a seventh aspect of the present invention, the voltage fluctuation control device is driven by a capacitor, a converter that converts a DC voltage output from the capacitor into a DC voltage of a different level, and power supplied from the capacitor via the converter. A voltage fluctuation control device for a vehicle including a load including an electric motor, a target power deriving unit for deriving a target power output from the electric motor according to a required driving force for the vehicle, and a response according to the target power A power consumption deriving unit for deriving the power consumption of the motor; a load side voltage target value setting unit for setting a target value of the load side voltage of the converter according to the power consumption of the motor derived by the power consumption deriving unit; the provided, when the remaining capacity of the storage battery is within a predetermined range, said load-side voltage target value setting unit, the difference between the target value and the actual value of the load side voltage of the converter When the load-side voltage change width limit according to the remaining capacity of the capacitor is exceeded, fluctuations in the target value of the load-side voltage are suppressed within the change width limit centered on the actual value of the load-side voltage. It is characterized by doing.

The voltage fluctuation control apparatus according to an eighth aspect of the present invention is the voltage fluctuation control apparatus according to the seventh aspect , wherein the load side voltage target value setting unit is set when a remaining capacity of the battery is outside the predetermined range. Is characterized in that a predetermined amount is set as the target value of the load side voltage.

A voltage fluctuation control apparatus according to a ninth aspect of the present invention is the voltage fluctuation control apparatus according to the seventh aspect , wherein the load side voltage target value setting unit is configured when a remaining capacity of the battery is outside the predetermined range. Holds the previous target value as the target value of the load side voltage.

A voltage fluctuation control apparatus according to a tenth aspect of the present invention is the voltage fluctuation control apparatus according to the seventh aspect, wherein when the remaining capacity of the capacitor is outside the predetermined range, the drive of the converter is suspended. It is characterized by control.

The voltage fluctuation control device according to an eleventh aspect of the present invention is driven by a capacitor, a converter that converts a DC voltage output from the capacitor into a DC voltage of a different level, and power supply from the capacitor via the converter. A voltage fluctuation control device for a vehicle including a load including an electric motor, a target power deriving unit for deriving a target power output from the electric motor according to a required driving force for the vehicle, and a response according to the target power A power consumption deriving unit for deriving the power consumption of the motor; a load side voltage target value setting unit for setting a target value of the load side voltage of the converter according to the power consumption of the motor derived by the power consumption deriving unit; when the equipped, allowable power range from the limit power of a preset discharge side to the capacitor until the charge side power limit is equal to or more than the threshold, the load-side When the difference between the target value and the actual value of the load side voltage of the converter exceeds the limit of change range of the load side voltage according to the allowable power range, the target pressure value setting unit sets the target value of the load side voltage. The fluctuation is suppressed within the change width limit centered on the actual value of the load side voltage.

A voltage fluctuation control apparatus according to a twelfth aspect of the present invention is the voltage fluctuation control apparatus according to the eleventh aspect , wherein the load side voltage target value setting unit is set when the allowable power range is less than the threshold value. Is characterized in that a predetermined amount is set as the target value of the load side voltage.

A voltage fluctuation control apparatus according to a thirteenth aspect of the present invention is the voltage fluctuation control apparatus according to the eleventh aspect, wherein when the allowable power range is less than the threshold value, the drive of the converter is suspended. It is characterized by control.

A voltage fluctuation control apparatus according to a fourteenth aspect of the present invention is the voltage fluctuation control apparatus according to the eleventh aspect , wherein the load side voltage target value setting unit is set when the allowable power range is less than the threshold value. Holds the previous target value as the target value of the load side voltage.

According to the voltage fluctuation control apparatus of the invention described in claims 1 to 14, it is possible to suppress the progress of deterioration of the battery due to charge / discharge exceeding the limit power of the battery.

Block diagram showing internal configuration of series / parallel HEV The block diagram which shows the structure of the drive system of the vehicle shown in FIG. The block diagram which shows the internal structure of management ECU123 A flowchart showing an operation when the V2 voltage target value setting unit 159 of the management ECU 123 sets the V2 voltage target value by the first setting method. The graph which shows the change width limit per unit time of V2 voltage according to battery temperature Tbatt used when V2 voltage target value setting part 159 calculates V2 voltage target value by a 1st setting method When the fluctuation of the V2 voltage per unit time is limited to the V2 voltage change width limit value thV1 or less, the battery 101 according to the change of the V2 voltage according to the traveling of the vehicle and the V2 voltage with respect to the allowable power range of the battery 101. Of an example of changes in charge / discharge power Flowchart showing the operation when the V2 voltage target value setting unit 159 of the management ECU 123 sets the V2 voltage target value by the second setting method. The graph which shows the change width limit per unit time of the V2 voltage according to the SOC of the battery 101 used when the V2 voltage target value setting unit 159 calculates the V2 voltage target value by the second setting method. A flowchart showing an operation when the V2 voltage target value setting unit 159 of the management ECU 123 sets the V2 voltage target value by the third setting method. The graph which shows the variation limit per unit time of the V2 voltage according to the allowable power range of the battery 101, which is used when the V2 voltage target value setting unit 159 calculates the V2 voltage target value by the third setting method. The figure which shows the allowable electric power range which changes with SOC of a capacitor | condenser The figure which shows the allowable electric power range which changes with the temperature of the battery The block diagram which shows the structure of the drive system provided in vehicles, such as HEV or EV An example of the change in the charge / discharge power of the battery according to the change of the V2 voltage according to the traveling of the vehicle and the V2 voltage with respect to the allowable power range of the battery

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A HEV (Hybrid Electrical Vehicle) includes an electric motor and an internal combustion engine, and travels by the driving force of the electric motor and / or the internal combustion engine according to the traveling state of the HEV. There are two types of HEVs: a series method and a parallel method. The series-type HEV travels by the driving force of the electric motor. The internal combustion engine is used only for power generation, and the electric power generated by the generator by the driving force of the internal combustion engine is charged in the capacitor or supplied to the electric motor. The parallel HEV travels by the driving force of one or both of the electric motor and the internal combustion engine.

  A series / parallel HEV in which both the above systems are combined is also known. In this method, the transmission system of the driving force is switched between the series method and the parallel method by opening or closing (engaging / disconnecting) the clutch according to the running state of the HEV.

  FIG. 1 is a block diagram showing the internal configuration of a series / parallel HEV. A series / parallel HEV (hereinafter referred to as “vehicle”) shown in FIG. 1 includes a battery (BATT) 101, a temperature sensor (TEMP) 103, a converter (CONV) 105, a first inverter (TRC INV) 107, , An electric motor (TRC MOT) 109, an internal combustion engine (ENG) 111, a generator (GEN MOT) 113, a second inverter (GEN INV) 115, a clutch 117, a gear box (hereinafter simply referred to as “gear”) ), A vehicle speed sensor 121, a management ECU (FI / MG ECU) 123, a motor ECU (MOT / GEN ECU) 125, and a battery ECU (BATT ECU) 127. In addition, the solid line arrow in FIG. 1 indicates value data, and the alternate long and short dash line arrow indicates a control signal including instruction contents.

  FIG. 2 is a block diagram showing the configuration of the vehicle drive system shown in FIG. Constituent elements common to FIG. 1 shown in FIG. 2 are denoted by the same reference numerals. As shown in FIG. 2, between the converter 105 and the first inverter 107 and the second inverter 115, a smoothing capacitor C and a voltage sensor 129 (both not shown in FIG. 1) are connected in parallel to the converter 105, respectively. Is provided. The voltage sensor 129 measures a V2 voltage that is a DC voltage equal to the voltage across the smoothing capacitor C.

  The storage battery 101 has a plurality of storage cells connected in series, and supplies a high voltage of, for example, 100 to 200V. The storage cell is a secondary battery such as a nickel metal hydride battery or a lithium ion battery. Charging / discharging of the battery 101 is repeated within the range of the control SOC in which the battery 101 can be used (lower limit SOC to upper limit SOC). The temperature sensor 103 detects the temperature (hereinafter referred to as “battery temperature”) Tbatt of the battery 101. A signal indicating the battery temperature Tbatt detected by the temperature sensor 103 is sent to the battery ECU 127 and the management ECU 123.

  Converter 105 boosts or lowers the DC output voltage of battery 101 while maintaining the direct current. The first inverter 107 converts a DC voltage into an AC voltage and supplies a three-phase current to the electric motor 109. Further, the first inverter 107 converts the AC voltage input during the regenerative operation of the electric motor 109 into a DC voltage and charges the battery 101.

  The electric motor 109 generates power for the vehicle to travel. Torque generated by the electric motor 109 is transmitted to the drive shaft 131 via the gear 119. Note that the rotor of the electric motor 109 is directly connected to the gear 119. The electric motor 109 operates as a generator when the vehicle is decelerated (during regenerative braking), and the electric power generated by the electric motor 109 is charged in the capacitor 101.

  The internal combustion engine 111 is used only for driving the generator 113 when the clutch 117 is disconnected and the vehicle travels in series. However, when the clutch 117 is engaged, the output of the internal combustion engine 111 is transmitted to the drive shaft 131 via the generator 113, the clutch 117, and the gear 119 as mechanical energy for the hybrid vehicle to travel. The internal combustion engine 111 is directly connected to the rotor of the generator 113.

  The generator 113 generates electric power using the power of the internal combustion engine 111. The electric power generated by the generator 113 is charged in the battery 101 or supplied to the electric motor 109. The second inverter 115 converts the AC voltage generated by the generator 113 into a DC voltage. The electric power converted by the second inverter 115 is charged in the battery 101 or supplied to the electric motor 109 via the first inverter 107.

  The clutch 117 connects and disconnects the transmission path of the driving force from the internal combustion engine 111 to the driving wheel 133 based on an instruction from the management ECU 123. The gear 119 is a one-stage fixed gear corresponding to, for example, the fifth speed. Therefore, the gear 119 converts the driving force from the internal combustion engine 111 or the driving force from the electric motor 109 via the generator 113 into a rotation speed and torque at a specific gear ratio, and transmits them to the drive shaft 131. The vehicle speed sensor 121 detects the traveling speed (vehicle speed VP) of the vehicle. A signal indicating the vehicle speed VP detected by the vehicle speed sensor 121 is sent to the management ECU 123.

  The management ECU 123 calculates the required driving force based on the accelerator pedal opening (AP opening) and the vehicle speed VP according to the accelerator pedal operation of the driver of the vehicle, the calculation of the power output from the electric motor 109 according to the required driving force, the vehicle The calculation of the charging power based on the brake pedal depression force (BRK depression force) and the vehicle speed VP according to the driver's brake pedal operation, the calculation of the target value of the V2 voltage, which is a DC voltage equal to the voltage across the smoothing capacitor C, and the disconnection of the clutch 117 Control relating to contact, control of the internal combustion engine 111, input / output control of the battery 101, and the like are performed. In FIG. 1, the control by the management ECU 123 is indicated by a one-dot chain line. Details of the management ECU 123 will be described later.

  The motor ECU 125 controls the operation of the electric motor 109 or the generator 113 by switching control of the switching elements constituting the converter 105, the first inverter 107, and the second inverter 115, respectively. In FIG. 1, control of converter 105, first inverter 107, and second inverter 115 by motor ECU 125 is indicated by a one-dot chain line.

  The battery ECU 127 derives the SOC and the like of the battery 101 based on the battery temperature Tbatt obtained from the temperature sensor 103 and information Ibatt such as the charge / discharge current and terminal voltage of the battery 101.

  FIG. 3 is a block diagram showing an internal configuration of the management ECU 123. As shown in FIG. 3, the management ECU 123 includes a required driving force calculation unit 151, a target power calculation unit 153, a power consumption calculation unit 155, a generated power calculation unit 157, and a V2 voltage target value setting unit 159. .

  The required driving force calculation unit 151 calculates the required driving force based on the AP opening degree and the vehicle speed VP. The target power calculation unit 153 calculates the target power output from the electric motor 109 according to the required driving force. The power consumption calculation unit 155 calculates the power consumption of the electric motor 109 according to the target power of the electric motor 109. The generated power calculation unit 157 calculates the power generated by the electric motor 109 that operates as a generator when the vehicle decelerates (during regenerative braking) based on the BRK pedaling force and the vehicle speed VP, or generates the internal combustion engine based on the required driving force The power generated by the generator 113 using the power of 111 is calculated. Hereinafter, the electric power generated by the electric motor 109 during the regenerative braking and the electric power generated by the electric generator 113 are collectively referred to as “generated electric power”.

  The V2 voltage target value setting unit 159 performs V2 based on the difference between the power consumption calculated by the discharge power calculation unit 155 and the power generation power calculated by the power generation power calculation unit 157 (power difference for unbalance = power consumption-power generation power). A voltage target value (hereinafter referred to as “V2 voltage target value”) is calculated, and the calculated change rate of the V2 voltage target value is set to the state of the capacitor 101 or the allowable power range of the capacitor 101 set for the state. Respond accordingly. Note that a signal indicating the V2 voltage target value set by the V2 voltage target value setting unit 159 is sent from the management ECU 123 to the motor ECU 125, and the motor ECU 125 controls the converter 105 so that the V2 voltage approaches the V2 voltage target value.

  Hereinafter, three examples in which the V2 voltage target value setting unit 159 calculates the V2 voltage target value will be described.

(First setting method)
In the first setting method, the V2 voltage target value setting unit 159 sets the V2 voltage target value in which the rate of change is suppressed according to the battery temperature Tbatt. FIG. 4 is a flowchart showing an operation when the V2 voltage target value setting unit 159 of the management ECU 123 sets the V2 voltage target value by the first setting method. FIG. 5 is a graph showing a change limit of the V2 voltage per unit time according to the battery temperature Tbatt used when the V2 voltage target value setting unit 159 calculates the V2 voltage target value by the first setting method. It is.

  As shown in FIG. 4, the V2 voltage target value setting unit 159 increases the energy efficiency based on the above-described unbalanced power difference (the difference between the power consumed by the motor 109 and the power generated by the generator 113). The priority V2 voltage target value is calculated (step S101). Next, the V2 voltage target value setting unit 159 determines whether or not the battery temperature Tbatt is not less than the first threshold value t1 and not more than the second threshold value t2 (t1 ≦ Tbatt ≦ t2) (step S103). . Note that “first threshold value t1 <second threshold value t2”. If it is determined in step S103 that “t1 ≦ Tbatt ≦ t2”, the process proceeds to step S105. If it is determined that “Tbatt <t1” or “Tbatt> t2”, the process proceeds to step S121.

  In step S105, the V2 voltage target value setting unit 159 determines a change width limit value per unit time of the V2 voltage according to the battery temperature Tbatt (hereinafter referred to as “V2 voltage change width limit value”) from the table shown in the graph of FIG. ) ThV1 is derived. Next, the V2 voltage target value setting unit 159 acquires the actual value of the V2 voltage (hereinafter referred to as “V2 voltage actual value”) measured by the voltage sensor 129 shown in FIG. 2 (step S107). Next, the V2 voltage target value setting unit 159 has a difference (hereinafter referred to as “V2 voltage difference value”) ΔV2 (= V2 voltage target value) between the V2 voltage target value calculated in step S101 and the V2 voltage actual value acquired in step S107. -V2 voltage actual value) is calculated (step S109).

  Next, the V2 voltage target value setting unit 159 determines whether or not the absolute value of the V2 voltage difference value ΔV2 exceeds the V2 voltage change width limit value thV1 derived in step S105 (| ΔV2 |> thV1) (step S111), if | ΔV2 |> thV1, the process proceeds to step S113, and if | ΔV2 | ≦ thV1, the process returns to step S101. In step S113, if the V2 voltage difference value ΔV2 is a positive value, the V2 voltage target value setting unit 159 adds the V2 voltage change width limit value thV1 to the V2 voltage actual value acquired in step S107 (V2 voltage actual value). Value + thV1) is set to the V2 voltage target value, and if the V2 voltage difference value ΔV2 is a negative value, a value obtained by subtracting the V2 voltage change width limit value thV1 from the V2 voltage actual value (V2 voltage actual value−thV1) is V2 Set the voltage target value.

  According to the V2 voltage target value set in step S113, the fluctuation of the V2 voltage per unit time is limited to the V2 voltage change width limit value thV1 or less. FIG. 6 shows changes in the V2 voltage with respect to the allowable power range of the battery 101 and the V2 voltage according to the traveling of the vehicle when the fluctuation of the V2 voltage per unit time is limited to the V2 voltage change width limit value thV1 or less. It is a figure which shows an example of the change of the charging / discharging electric power of the corresponding electrical storage device 101. 6 indicates a change in the V2 voltage according to the V2 voltage target value giving priority to energy efficiency, and a change in the charge / discharge power of the battery 101 according to the change in the V2 voltage. As shown in FIG. 6, when the variation of the V2 voltage according to the V2 voltage target value giving priority to the energy efficiency calculated in step S101 becomes large, the change of the V2 voltage is suppressed by suppressing the change rate of the V2 voltage target value. Will also be moderate. Furthermore, since the change in the charging / discharging power of the battery 101 according to the slowly changing V2 voltage also becomes gentle, as shown in FIG. 6, the discharging power of the battery 101 or the charging power to the battery 101 is not allowed for the battery 101. Within the power range.

  Step S121 is performed when the battery temperature Tbatt is extremely low or extremely high. At this time, the V2 voltage target value setting unit 159 sets the same value as the most recent V2 voltage target value (previous V2 voltage target value) set before performing step S121 so that the V2 voltage becomes substantially constant. Set to value. In step S121, the V2 voltage target value setting unit 159 may set a predetermined fixed value as the V2 voltage target value. In step S121, the V2 voltage target value setting unit 159 may instruct the motor ECU 125 to stop driving the converter 105 without setting the V2 voltage target value.

(Second setting method)
In the second setting method, the V2 voltage target value setting unit 159 sets the V2 voltage target value in which the rate of change is suppressed according to the SOC of the battery 101. FIG. 7 is a flowchart showing an operation when the V2 voltage target value setting unit 159 of the management ECU 123 sets the V2 voltage target value by the second setting method. Further, FIG. 8 shows the change width limit per unit time of the V2 voltage according to the SOC of the battery 101 used when the V2 voltage target value setting unit 159 calculates the V2 voltage target value by the second setting method. It is a graph.

  As shown in FIG. 7, the V2 voltage target value setting unit 159 increases the energy efficiency based on the above-described unbalanced power difference (the difference between the power consumed by the motor 109 and the power generated by the generator 113). The priority V2 voltage target value is calculated (step S201). Next, the V2 voltage target value setting unit 159 determines whether or not the SOC of the battery 101 is not less than the first threshold value s1 and not more than the second threshold value s2 (s1 ≦ SOC ≦ s2) (step S203). ). Note that “first threshold value s1 <second threshold value s2”. If it is determined in step S203 that “s1 ≦ SOC ≦ s2”, the process proceeds to step S205. If it is determined that “SOC <s1” or “SOC> s2”, the process proceeds to step S221.

  In step S205, the V2 voltage target value setting unit 159 determines the change width limit value per unit time of the V2 voltage according to the SOC (hereinafter referred to as “V2 voltage change width limit value”) thV2 from the table shown in the graph of FIG. Is derived. Next, the V2 voltage target value setting unit 159 acquires the actual value of the V2 voltage (hereinafter referred to as “V2 voltage actual value”) measured by the voltage sensor 129 shown in FIG. 2 (step S207). Next, the V2 voltage target value setting unit 159 determines the difference between the V2 voltage target value calculated in step S201 and the V2 voltage actual value acquired in step S207 (hereinafter referred to as “V2 voltage difference value”) ΔV2 (= V2 voltage target value). -V2 voltage actual value) is calculated (step S209).

  Next, the V2 voltage target value setting unit 159 determines whether or not the absolute value of the V2 voltage difference value ΔV2 exceeds the V2 voltage change width limit value thV2 derived in step S205 (| ΔV2 |> thV2) (step S21), if | ΔV2 |> thV2, the process proceeds to step S213, and if | ΔV2 | ≦ thV2, the process returns to step S201. In step S213, if the V2 voltage difference value ΔV2 is a positive value, the V2 voltage target value setting unit 159 adds the V2 voltage change width limit value thV2 to the V2 voltage actual value acquired in step S207 (V2 voltage actual value). Value + thV2) is set to the V2 voltage target value, and if the V2 voltage difference value ΔV2 is a negative value, a value obtained by subtracting the V2 voltage change width limit value thV2 from the V2 voltage actual value (V2 voltage actual value−thV2) is V2 Set the voltage target value.

  According to the V2 voltage target value set in step S213, the fluctuation of the V2 voltage per unit time is limited to the V2 voltage change width limit value thV2 or less. That is, as shown in FIG. 6, when the variation of the V2 voltage according to the V2 voltage target value giving priority to the energy efficiency calculated in step S201 becomes large, if the rate of change of the V2 voltage target value is suppressed, V2 The change in voltage also becomes gradual. Furthermore, since the change in the charging / discharging power of the battery 101 according to the slowly changing V2 voltage also becomes gentle, as shown in FIG. 6, the discharging power of the battery 101 or the charging power to the battery 101 is not allowed for the battery 101. Within the power range.

  Step S221 is performed when the SOC is extremely low or extremely high. At this time, the V2 voltage target value setting unit 159 sets the V2 voltage target to the same value as the most recent V2 voltage target value (previous V2 voltage target value) set before performing step S221 so that the V2 voltage becomes substantially constant. Set to value. In step S221, the V2 voltage target value setting unit 159 may set a predetermined fixed value as the V2 voltage target value. In step S221, the V2 voltage target value setting unit 159 may not set the V2 voltage target value, and the management ECU 123 may instruct the motor ECU 125 to stop driving the converter 105.

(Third setting method)
In the third setting method, the V2 voltage target value setting unit 159 sets a V2 voltage target value in which the rate of change is suppressed according to the allowable power range of the battery 101. Note that the allowable power range of the battery 101 differs depending on the temperature of the battery 101 (battery voltage Tbatt) and the SOC of the battery 101 as shown in FIGS. 11 and 12. FIG. 9 is a flowchart showing an operation when the V2 voltage target value setting unit 159 of the management ECU 123 sets the V2 voltage target value by the third setting method. Further, FIG. 10 shows a change width limit per unit time of the V2 voltage according to the allowable power range of the battery 101, which is used when the V2 voltage target value setting unit 159 calculates the V2 voltage target value by the third setting method. It is a graph which shows.

  As shown in FIG. 9, the V2 voltage target value setting unit 159 increases the energy efficiency based on the above-described unbalanced power difference (the difference between the power consumed by the motor 109 and the power generated by the generator 113). A priority V2 voltage target value is calculated (step S301). Next, the V2 voltage target value setting unit 159 derives an allowable power range from the discharge-side limit power preset to the capacitor 101 to the charge-side limit power based on the battery voltage Tbatt and the SOC of the capacitor 101. (Step S302). Next, V2 voltage target value setting unit 159 determines whether or not the allowable power range of battery 101 is equal to or greater than threshold value Pth (allowable power range ≧ Pth) (step S303). If it is determined in step S303 that “allowable power range ≧ Pth”, the process proceeds to step S305. If it is determined that “allowable power range <Pth”, the process proceeds to step S321.

  In step S305, the V2 voltage target value setting unit 159 determines a change width limit value per unit time of the V2 voltage according to the allowable power range (hereinafter referred to as “V2 voltage change width limit value”) from the table shown in FIG. ) ThV3 is derived. Next, the V2 voltage target value setting unit 159 acquires the actual value of the V2 voltage (hereinafter referred to as “V2 voltage actual value”) measured by the voltage sensor 129 shown in FIG. 2 (step S307). Next, the V2 voltage target value setting unit 159 has a difference (hereinafter referred to as “V2 voltage difference value”) ΔV2 (= V2 voltage target value) between the V2 voltage target value calculated in step S301 and the V2 voltage actual value acquired in step S307. -V2 voltage actual value) is calculated (step S309).

  Next, the V2 voltage target value setting unit 159 determines whether or not the absolute value of the V2 voltage difference value ΔV2 exceeds the V2 voltage change width limit value thV3 derived in step S305 (| ΔV2 |> thV3) (step S311), if | ΔV2 |> thV3, the process proceeds to step S313, and if | ΔV2 | ≦ thV3, the process returns to step S301. In step S313, if the V2 voltage difference value ΔV2 is a positive value, the V2 voltage target value setting unit 159 adds the V2 voltage change width limit value thV3 to the V2 voltage actual value acquired in step S307 (V2 voltage actual value). Value + thV3) is set to the V2 voltage target value, and if the V2 voltage difference value ΔV2 is a negative value, a value obtained by subtracting the V2 voltage change width limit value thV3 from the V2 voltage actual value (V2 voltage actual value−thV3) is V2 Set the voltage target value.

  According to the V2 voltage target value set in step S313, the fluctuation of the V2 voltage per unit time is limited to the V2 voltage change width limit value thV3 or less. That is, as shown in FIG. 6, when the variation of the V2 voltage according to the V2 voltage target value giving priority to the energy efficiency calculated in step S301 becomes large, if the rate of change of the V2 voltage target value is suppressed, V2 The change in voltage also becomes gradual. Furthermore, since the change in the charging / discharging power of the battery 101 according to the slowly changing V2 voltage also becomes gentle, as shown in FIG. 6, the discharging power of the battery 101 or the charging power to the battery 101 is not allowed for the battery 101. Within the power range.

  Step S321 is performed when the allowable power range of the battery 101 is extremely limited. At this time, the V2 voltage target value setting unit 159 sets the same value as the most recent V2 voltage target value (previous V2 voltage target value) set before performing step S321 so that the V2 voltage becomes substantially constant. Set to value. In step S321, the V2 voltage target value setting unit 159 may set a predetermined fixed value as the V2 voltage target value. In step S321, V2 voltage target value setting unit 159 may instruct motor ECU 125 to stop driving converter 105 without setting the V2 voltage target value.

  As described above, in this embodiment, since the rate of change of the V2 voltage target value is suppressed according to the state of the capacitor 101 or the allowable power range of the capacitor 101 set for the state, the V2 voltage is steep. Does not fluctuate. That is, as shown in FIG. 6, when the fluctuation of the V2 voltage according to the V2 voltage target value giving priority to energy efficiency becomes large, if the rate of change of the V2 voltage target value is suppressed, the change of the V2 voltage also moderates. Become. Furthermore, since the change in the charging / discharging power of the battery 101 according to the slowly changing V2 voltage also becomes gentle, as shown in FIG. 6, the discharging power of the battery 101 or the charging power to the battery 101 is not allowed for the battery 101. Within the power range. As a result, the progress of deterioration of the battery 101 can be suppressed.

  In this embodiment, the series / parallel HEV has been described as an example. However, a series HEV, a parallel HEV, or an EV (Electrical Vehicle) may be used. Further, in the present embodiment, the rate of change when the V2 voltage target value increases and the rate of change when the V2 voltage target value decreases are suppressed, but either one of the two types of suppression may be performed. When only suppressing the rate of change when the V2 voltage target value increases, the generated power calculation unit 157 shown in FIG. 3 is not used. Also, the rate of change is suppressed when the V2 voltage target value decreases.

101 Battery (BATT)
103 Temperature sensor (TEMP)
105 Converter (CONV)
107 First inverter (TRC INV)
109 Electric motor (TRC MOT)
111 Internal combustion engine (ENG)
113 Generator (GEN MOT)
115 Second inverter (GEN INV)
117 Clutch 119 Gearbox 121 Vehicle speed sensor 123 Management ECU (FI / MG ECU)
125 Motor ECU (MOT / GEN ECU)
127 Battery ECU (BATT ECU)
129 Voltage sensor 131 Driving shaft 133 Driving wheel 151 Required driving force calculation unit 153 Target power calculation unit 155 Power consumption calculation unit 157 Generated power calculation unit 159 V2 voltage target value setting unit C Smoothing capacitor

Claims (14)

A capacitor,
A converter that converts the DC voltage output from the battery into a DC voltage of a different level;
A load including an electric motor driven by power supply from the capacitor via the converter, and a voltage fluctuation control device in a vehicle,
A target power deriving unit for deriving a target power output by the electric motor according to a required driving force for the vehicle;
A power consumption deriving unit for deriving power consumption of the electric motor according to the target power;
A load side voltage target value setting unit for setting a target value of the load side voltage of the converter according to the power consumption of the electric motor derived by the power consumption deriving unit;
A power generation power deriving unit for deriving power generated by the motor that operates as a power generator when the vehicle decelerates ,
The load side voltage target value setting unit suppresses the rate of change of the target value of the load side voltage according to the state of the capacitor or the limit power of the capacitor set in advance for the state , and the A voltage for deriving a target value of a load side voltage of the converter based on a difference between power consumption of the motor derived by the power consumption deriving unit and power generation power of the motor derived by the generated power deriving unit Fluctuation control device. The voltage fluctuation control device according to claim 1 ,
The load includes a generator that generates electricity by operating an internal combustion engine,
The generated power deriving unit derives the electric power generated by the generator according to the required driving force for the vehicle,
The load-side voltage target value setting unit is based on a difference between the electric power consumption of the electric motor derived by the electric power consumption deriving unit and the electric power generated by the electric motor and the electric generator derived by the electric power generation deriving unit. A voltage fluctuation control apparatus for deriving a target value of a load side voltage.   A capacitor,
  A converter that converts the DC voltage output from the battery into a DC voltage of a different level;
  A load including an electric motor driven by power supply from the capacitor via the converter, and a voltage fluctuation control device in a vehicle,
  A target power deriving unit for deriving a target power output by the electric motor according to a required driving force for the vehicle;
  A power consumption deriving unit for deriving power consumption of the electric motor according to the target power;
  A load-side voltage target value setting unit that sets a target value of the load-side voltage of the converter according to the power consumption of the motor derived by the power consumption deriving unit;
  When the temperature of the battery is within a predetermined temperature range,
  The load-side voltage target value setting unit, when a difference between a target value and an actual value of the load-side voltage of the converter exceeds a change width limit of the load-side voltage according to the temperature of the battery, A voltage fluctuation control device that suppresses fluctuation of a target value within the change width limit centering on an actual value of the load side voltage. The voltage fluctuation control device according to claim 3 ,
When the temperature of the battery is outside the predetermined temperature range, the load side voltage target value setting unit sets a predetermined predetermined amount as a target value of the load side voltage. The voltage fluctuation control device according to claim 3 ,
When the temperature of the battery is outside the predetermined temperature range, the voltage fluctuation control device controls to stop driving the converter. The voltage fluctuation control device according to claim 3 ,
When the temperature of the battery is outside the predetermined temperature range, the load side voltage target value setting unit holds a previous target value as a target value of the load side voltage.   A capacitor,
  A converter that converts the DC voltage output from the battery into a DC voltage of a different level;
  A load including an electric motor driven by power supply from the capacitor via the converter, and a voltage fluctuation control device in a vehicle,
  A target power deriving unit for deriving a target power output by the electric motor according to a required driving force for the vehicle;
  A power consumption deriving unit for deriving power consumption of the electric motor according to the target power;
  A load-side voltage target value setting unit that sets a target value of the load-side voltage of the converter according to the power consumption of the motor derived by the power consumption deriving unit;
  When the remaining capacity of the battery is within a predetermined range,
  When the difference between the target value and the actual value of the load-side voltage of the converter exceeds the load-side voltage change width limit according to the remaining capacity of the capacitor, the load-side voltage target value setting unit The voltage fluctuation control apparatus is characterized in that the fluctuation of the target value is suppressed within the change width limit centered on the actual value of the load side voltage. The voltage fluctuation control device according to claim 7 ,
When the remaining capacity of the battery is outside the predetermined range, the load-side voltage target value setting unit sets a certain predetermined amount as a target value of the load-side voltage. The voltage fluctuation control device according to claim 7 ,
When the remaining capacity of the battery is outside the predetermined range, the load-side voltage target value setting unit holds a previous target value as a target value of the load-side voltage. The voltage fluctuation control device according to claim 7 ,
When the remaining capacity of the capacitor is outside the predetermined range, the voltage fluctuation control device is controlled to stop driving the converter.   A capacitor,
  A converter that converts the DC voltage output from the battery into a DC voltage of a different level;
  A load including an electric motor driven by power supply from the capacitor via the converter, and a voltage fluctuation control device in a vehicle,
  A target power deriving unit for deriving a target power output by the electric motor according to a required driving force for the vehicle;
  A power consumption deriving unit for deriving power consumption of the electric motor according to the target power;
  A load-side voltage target value setting unit that sets a target value of the load-side voltage of the converter according to the power consumption of the motor derived by the power consumption deriving unit;
  When the allowable power range from the limit power on the discharge side to the limit power on the charge side preset in the battery is equal to or greater than a threshold value,
  The load side voltage target value setting unit, when a difference between a target value and an actual value of the load side voltage of the converter exceeds a change width limit of the load side voltage according to the allowable power range, A voltage fluctuation control device that suppresses fluctuation of a target value within the change width limit centering on an actual value of the load side voltage. The voltage fluctuation control device according to claim 11 ,
When the allowable power range is less than the threshold value, the load side voltage target value setting unit sets a certain predetermined amount as a target value of the load side voltage. The voltage fluctuation control device according to claim 11 ,
When the allowable power range is less than the threshold value, the voltage fluctuation control device controls to stop driving the converter. The voltage fluctuation control device according to claim 11 ,
When the allowable power range is less than the threshold value, the load side voltage target value setting unit holds a previous target value as a target value of the load side voltage.

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