JP2010115048A - Power supply system and electric power balance control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fully cope with an output request with all of a plurality of power storage devices corresponding to a request for a load device while normally using the power storage devices in a well-balanced way, in a power supply system equipped with the power storage devices. <P>SOLUTION: The output electric power upper limit value POmax from the power supply system is set within a setting range of discharge electric power target values Pb1, Pb2 of each power storage device so as to normally maintain a discharge electric power distribution rate k set in consideration of the discharge balance among the power storage devices. When the output request for the load devices is increased, the output electric power upper limit value POmax is set according to the total of discharge electric power upper limit values Wout1, Wout2 so as to take precedence of the increase in the output electric power over the maintenance of the discharge electric power distribution rate k. In this case, the discharge electric power target values Pb1, Pb2 of each power storage device once set according to the discharge electric power distribution rate k are set again. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to charge / discharge control of a power supply system including a plurality of power storage devices.

  In recent years, in consideration of environmental problems, electric vehicles using an electric motor as a driving force source, such as an electric vehicle, a hybrid vehicle, and a fuel cell vehicle, have attracted attention. In such an electric vehicle, a power storage device represented by a secondary battery, an electric double layer capacitor, or the like is used to supply electric power to the motor or store kinetic energy converted into electric energy during regenerative braking. Is installed.

  In a vehicle using such an electric motor as a driving force source, it is desirable to increase the charge / discharge capacity of the power storage device in order to improve the running performance such as acceleration performance and running distance. As a method for increasing the charge / discharge capacity, a configuration in which a plurality of power storage devices are mounted is disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-295782 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2008-109840 (Patent Document 2). It is described in.

  In Patent Document 1, converters are provided independently for two power storage devices, and the output voltage of one power storage device is controlled to a target voltage by each converter, while the input / output of the other power storage device is controlled. A configuration is described in which input / output power of each power storage device is controlled by controlling the current to be a target current.

Further, in Patent Document 2, a charge power distribution rate and a discharge power distribution rate between power storage devices are calculated based on a charge allowable amount and a discharge allowable amount of a plurality of power storage devices, and according to these distribution rates, It describes that charge / discharge control is performed in which an input / output power target value is set.
JP 2007-295782 A JP 2008-109840 A

  According to the charge / discharge control described in Patent Document 2, even when the charge / discharge states of a plurality of power storage devices are different, it is possible to improve the performance of the power supply system by using each power storage device in a balanced manner. .

  However, since it is assumed that the power target value of each power storage device is set according to the power distribution ratio among the plurality of power storage devices, the output power from the power supply system up to the limit of the upper limit power that can be discharged by the plurality of power storage devices as a whole May not be secured. Therefore, when charge / discharge control according to Patent Document 2 is applied uniformly, a plurality of power storage devices can be used in a well-balanced manner. There may be a situation where the power system capacity cannot be fully utilized, which cannot be fully met.

  The present invention has been made to solve such problems, and in a power supply system including a plurality of power storage devices, a plurality of power devices are normally used in a balanced manner, while a demand for a load device is required. Accordingly, it is possible to realize a control that can meet the maximum output demand of the entire plurality of power storage devices.

  A power supply system according to the present invention is a power supply system that supplies power to a load device, wherein the power line is connected to the load device, a plurality of power storage devices, a plurality of first power converters, and a power storage device power. A management unit and a power balance management unit are provided. The plurality of first power converters are respectively disposed between the power line and the plurality of power storage devices, and control power conversion between the plurality of power storage devices and the power line based on an output power target value of each power storage device. Configured as follows. The power storage device power management unit sets a discharge power distribution ratio among the plurality of power storage devices at the time of power supply to the load device based on a state comparison of the plurality of power storage devices, and outputs required power to the power supply system and The output power target value of each power storage device is set according to the discharge power distribution ratio. The power balance management unit sets a power consumption upper limit power value of the load device in order to limit the required output power. The power balance management unit selects one of the first and second modes based on an output request to the load device, and at the time of selecting the first mode, a predetermined power storage device among the plurality of power storage devices The upper limit power consumption value is defined as the output upper limit power of the power supply system, which is the sum of the discharge power upper limit value and the maximum output power target value of each remaining power storage device according to the product of the discharge power upper limit value and the discharge power distribution ratio. On the other hand, when the second mode is selected, the consumption upper limit power value is set with the sum of the discharge power upper limit values of the respective power storage devices as the output upper limit power. The power balance management unit maintains the output power target value set according to the discharge power distribution ratio when the first mode is selected, while the output power from each power storage device is selected when the second mode is selected. The output power target value of each power storage device is reset within a range that does not exceed the corresponding discharge power upper limit value.

  In the power balance control method for a power supply system according to the present invention, the power supply system includes the power line, a plurality of power storage devices, and a plurality of first power converters. The power balance control method includes: setting a discharge power upper limit value for each of the plurality of power storage devices based on the respective states of the plurality of power storage devices; and a load device based on a state comparison of the plurality of power storage devices Setting a discharge power distribution ratio among a plurality of power storage devices at the time of power supply to the power supply, and setting an output power target value of each power storage device according to the output required power and the discharge power distribution ratio to the power supply system And a step of selecting one of the first and second modes based on an output request to the load device, and a discharge power upper limit of a predetermined power storage device among the plurality of power storage devices when the first mode is selected Output request so that the sum of the value and the maximum output power target value of each remaining power storage device according to the product of the discharge power upper limit value and the discharge power distribution rate is the output upper limit power of the power supply system Setting the upper limit power consumption value of the load device for power limitation, and when selecting the second mode, set the upper limit power consumption value so that the sum of the discharge power upper limit values of each power storage device is the output upper limit power. A step of setting, a step of maintaining an output power target value set in accordance with a discharge power distribution ratio when selecting the first mode, and a discharge corresponding to the output power from each power storage device when selecting the second mode. Resetting the output power target value of each power storage device within a range not exceeding the power upper limit value.

  According to the power supply system and the power balance control method thereof, the output power from the plurality of power storage devices is controlled according to the discharge power distribution ratio by the selection of the first mode at the normal time, while the output request of the load device is met. By selecting the second mode, the power output to the load device can be expanded to the upper limit power according to the sum of the discharge power upper limit values (Wout) of the respective power storage devices. Therefore, while normally discharging a plurality of power storage devices in a well-balanced manner, when the demand for output to the load device increases, it is possible to respond to the output request to the maximum within the range of allowable discharge power for the plurality of power storage devices as a whole. it can. As a result, the power supply system can be fully utilized.

  Preferably, the plurality of first power converters further control power conversion between the plurality of power storage devices and the power line based on an input power target value of each power storage device during power generation of the load device. Composed. The power storage device power management unit further sets a charge power distribution ratio among the plurality of power storage devices when receiving power from the load device based on a state comparison of the plurality of power storage devices, and requests input to the power supply system. The input power target value of each power storage device is set according to the power and the charge power distribution ratio. Furthermore, the power balance management unit selects one of the third and fourth modes based on a power generation request to the load device during power generation of the load device, and selects a plurality of power storage devices when selecting the third mode. The sum of the charging power upper limit value of the predetermined power storage device and the maximum input power target value of each remaining power storage device according to the product of the charging power upper limit value and the charging power distribution ratio is the input upper limit power of the power supply system. While setting the power generation upper limit power value of the load device for limiting the input required power, when the fourth mode is selected, the power generation upper limit power value is set with the sum of the charging power upper limit values of the respective power storage devices as the input upper limit power. Set. The power balance management unit maintains the input power target value set according to the charge power distribution ratio when the third mode is selected, while the input power to each power storage device is determined when the fourth mode is selected. The input power target value of each power storage device is reset within a range not exceeding the corresponding charge power upper limit value.

  Alternatively, the power balance control method includes a step of setting a charging power upper limit value of each of the plurality of power storage devices based on a state of each of the plurality of power storage devices, and a plurality of power storage devices at the time of receiving power from the load device. Based on the step of setting the charge power distribution ratio between the power supply system, the step of setting the input power target value of each power storage device according to the input request power and the charge power distribution ratio to the power supply system, and the power generation request to the load device Selecting one of the third and fourth modes, and when selecting the third mode, the charging power upper limit value of the predetermined power storage device among the plurality of power storage devices, the charging power upper limit value and the charging power Power generation of the load device for limiting the required input power so that the sum of the input power target value of each remaining power storage device according to the product of the distribution ratio and the maximum value of the input power is the input upper limit power of the power supply system A step of setting a power limit value, a step of setting a power generation upper limit power value so that a sum of charge power upper limit values of the respective power storage devices is set as an input upper limit power when the fourth mode is selected, At the time of selection, the step of maintaining the input power target value set according to the charging power distribution ratio, and at the time of selecting the fourth mode, the input power to each power storage device is within a range not exceeding the corresponding charging power upper limit value, Resetting the input power target value of each power storage device.

  In this way, even when charging a plurality of power storage devices with the generated power of the load device, the input power to the plurality of power storage devices is controlled according to the charge power distribution ratio by the selection of the third mode at the normal time. By selecting the fourth mode according to the power generation request to the load device, the generated power of the load device can be expanded to the upper limit power according to the sum of the charge power upper limit values (Win) of each power storage device. it can. Therefore, while normally charging a plurality of power storage devices in a well-balanced manner, when the demand for power generation to the load device increases, it is possible to respond to the power generation requests to the maximum within the range of allowable charging power for the plurality of power storage devices as a whole. it can.

  Preferably, the power supply system and the load device are mounted on an electric vehicle. The load device includes a rotating electric machine arranged so that power can be transmitted to and from the drive wheels of the electric vehicle, and the rotating electric machine and the power line so that the rotating electric machine outputs torque according to the torque command value. And a second power converter configured to control power conversion therebetween. The power balance management unit or the selecting step is configured to select one of the first and second modes based on the operation of the accelerator pedal.

  In this way, in an electric vehicle equipped with a rotating electrical machine for generating vehicle driving force, when the required power to the power supply system is increased in order to increase the driving force of the electric vehicle according to the accelerator pedal operation. While the output power from the power supply system can be increased to the full allowable value, a plurality of power storage devices in the power supply system can be used in a balanced manner during normal times.

  More preferably, the consumption upper limit power value of the load device indicates the consumption upper limit power value of the rotating electrical machine, and the torque upper limit value of the rotating electrical machine is set based on the rotation speed of the rotating electrical machine and the consumption upper limit power value.

  In this way, the torque command value of the rotating electrical machine can be appropriately set within the range of power consumption allowed for the rotating electrical machine in consideration of the power balance of the entire electric vehicle.

  According to the present invention, in a power supply system including a plurality of power storage devices, a plurality of power devices are normally used in a well-balanced manner, while the maximum of the plurality of power storage devices as a whole is met according to a request to the load device. Control capable of meeting the output request can be realized. As a result, the power supply system can be fully utilized.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

  FIG. 1 is an overall block diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with a power supply system according to the present embodiment.

  Referring to FIG. 1, hybrid vehicle 1000 includes an engine 2, motor generators MG <b> 1 and MG <b> 2, a power split mechanism 4, and wheels 6. Hybrid vehicle 1000 further includes power storage devices B 1 and B 2, converters 10 and 12, capacitor C, inverters 20 and 22, and ECU (Electronic Control Unit) 100.

  Power storage devices B1 and B2 correspond to “a plurality of power storage devices” in the present invention, and converters 10 and 12 correspond to “a plurality of first power converters” in the present invention. Inverters 20 and 22 and motor generators MG1 and MG2 constitute a “load device” in the present invention. In particular, motor generator MG2 corresponds to “rotary electric machine”, and inverters 20 and 22 correspond to “second power converter”.

  Power storage devices B1 and B2, converters 10 and 12, power lines PLM and PLN, and sensors and control elements associated therewith constitute a “power supply system” of the present invention.

  Hybrid vehicle 1000 travels using engine 2 and motor generator MG2 as power sources. That is, motor generator MG2 is arranged to be able to transmit power to and from the drive wheels.

  Power split device 4 is coupled to engine 2 and motor generators MG1, MG2 to distribute power between them. Power split device 4 is composed of, for example, a planetary gear mechanism having three rotation shafts of a sun gear, a planetary carrier, and a ring gear, and these three rotation shafts are connected to the rotation shafts of engine 2 and motor generators MG1 and MG2, respectively. It should be noted that engine 2 and motor generators MG1, MG2 can be mechanically connected to power split mechanism 4 by hollowing the rotor of motor generator MG1 and passing the crankshaft of engine 2 through the center thereof. Further, the rotating shaft of motor generator MG2 is coupled to wheel 6 by a reduction gear and an operating gear (not shown).

  Motor generator MG1 is incorporated in hybrid vehicle 1000 as operating as a generator driven by engine 2 and operating as an electric motor that can start engine 2. Motor generator MG2 is incorporated in hybrid vehicle 1000 as an electric motor that drives wheels 6.

  The power storage devices B1 and B2 are DC power sources that can be charged and discharged, and include, for example, secondary batteries such as nickel metal hydride and lithium ions. Power storage device B1 supplies power to converter 10 and is charged by converter 10 during power regeneration. Power storage device B2 supplies power to converter 12 and is charged by converter 12 during power regeneration.

  For example, a secondary battery having a maximum outputable power larger than that of power storage device B2 can be used for power storage device B1, and a secondary battery having a larger storage capacity than power storage device B1 can be used for power storage device B2. be able to. Thus, a high-power and large-capacity DC power source can be configured using the two power storage devices B1 and B2. Further, a large-capacity capacitor may be used for at least one of the power storage devices B1 and B2.

  Converter 10 boosts the voltage from power storage device B1 based on signal PWC1 from ECU 100, and outputs the boosted voltage to power line PLM. Converter 10 steps down the regenerative power supplied from inverters 20 and 22 via power line PLM to the voltage level of power storage device B1 based on signal PWC1, and charges power storage device B1. Furthermore, converter 10 stops the switching operation when it receives shutdown signal SD1 from ECU 100.

  Converter 12 is connected to power line (positive electrode) PLM and power line (negative electrode) NL in parallel with converter 10. Converter 12 boosts the voltage from power storage device B2 based on signal PWC2 from ECU 100, and outputs the boosted voltage to power line PLM. Converter 12 steps down the regenerative power supplied from inverters 20 and 22 via power line PLM to the voltage level of power storage device B2 based on signal PWC2, and charges power storage device B2. Furthermore, converter 12 stops the switching operation when it receives shutdown signal SD2 from ECU 100.

  Capacitor C is connected between power lines PLM and NL, and smoothes voltage fluctuations between power lines PLM and NL. DC voltage VH between power lines PLM and NL is changed to an output voltage from “power supply system” including power storage devices B1 and B2 and converters 10 and 12 to “load device” by inverters 20 and 22 and motor generators MG1 and MG2. Equivalent to. Hereinafter, the DC voltage VH is also referred to as a system voltage VH.

  Inverter 20 converts a DC voltage from power line PLM into a three-phase AC voltage based on signal PWI1 from ECU 100, and outputs the converted three-phase AC voltage to motor generator MG1. Inverter 20 converts the three-phase AC voltage generated by motor generator MG1 using the power of engine 2 into a DC voltage based on signal PWI1, and outputs the converted DC voltage to power line PLM.

  Inverter 22 converts a DC voltage from power line PLM into a three-phase AC voltage based on signal PWI2 from ECU 100, and outputs the converted three-phase AC voltage to motor generator MG2. Further, inverter 22 converts the three-phase AC voltage generated by motor generator MG2 by receiving the rotational force from wheel 6 during regenerative braking of the vehicle into a DC voltage based on signal PWI2, and converts the converted DC voltage to a power line. Output to PLM.

  Each of motor generators MG1 and MG2 is a three-phase AC rotating electric machine, for example, a three-phase AC synchronous motor generator. Motor generator MG1 is regeneratively driven by inverter 20, and outputs a three-phase AC voltage generated using the power of engine 2 to inverter 20. Motor generator MG1 is driven by power by inverter 20 when engine 2 is started, and cranks engine 2. Motor generator MG <b> 2 is driven by power by inverter 22, and generates a driving force for driving wheels 6. Motor generator MG <b> 2 is regeneratively driven by inverter 22 during regenerative braking of the vehicle, and outputs a three-phase AC voltage generated using the rotational force received from wheels 6 to inverter 22.

  In the power supply system, the voltage sensor 42, the current sensor 52, and the temperature sensor 62 that are disposed with respect to the power storage device B1, and the voltage sensor 44, the current sensor 54, and the temperature that are disposed with respect to the power storage device B2. A sensor 64 is provided.

  Voltage sensor 42 detects voltage VB1 of power storage device B1 and outputs it to ECU 100. Temperature sensor 62 detects temperature T1 of power storage device B1 and outputs it to ECU 100. Current sensor 52 detects current IB1 input / output from power storage device B1 to converter 10 and outputs the detected current to ECU 100.

  Voltage sensor 44 detects voltage VB2 of power storage device B2 and outputs it to ECU 100. Temperature sensor 64 detects temperature T2 of power storage device B2 and outputs it to ECU 100. Current sensor 54 detects current IB2 input / output from power storage device B2 to converter 12 and outputs the detected current to ECU 100.

  Furthermore, a voltage sensor 46 for detecting a voltage between terminals of the capacitor C, that is, a system voltage VH is arranged. The value detected by the voltage sensor 46 is output to the ECU 100.

  ECU 100 generates signals PWC <b> 1 and SD <b> 1 for controlling converter 10, and outputs any signal selected according to the state of the load device to converter 10. ECU 100 also generates signals PWC <b> 2 and SD <b> 2 for controlling converter 12, and outputs either signal to converter 12.

  Further, ECU 100 receives an input of power (hereinafter referred to as “required power”) PR required for the power supply system for driving the load device. For example, the required power PR is calculated by a vehicle ECU (not shown) that integrally controls the entire hybrid vehicle 1000 based on the accelerator pedal opening, the vehicle speed, and the like. PR> 0 is set when power is output from the power supply system, and PR <0 is set when power is input to the power supply system by the power generated by the load device.

  Further, ECU 100 generates signals PWI1 and PWI2 for driving inverters 20 and 22, respectively, and outputs the generated signals PWI1 and PWI2 to inverters 20 and 22, respectively.

FIG. 2 is a circuit diagram showing a configuration of converters 10 and 12 shown in FIG.
Referring to FIG. 2, converter 10 includes power semiconductor switching elements Q1, Q2, diodes D1, D2, and a reactor L1.

  In the present embodiment, an IGBT (Insulated Gate Bipolar Transistor) is applied as a power semiconductor switching element (hereinafter also simply referred to as “switching element”), but can be controlled on / off by a control signal. Any switching element can be applied. For example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or a bipolar transistor can be used.

  Switching elements Q1, Q2 are connected in series between power lines PLM and NL. Diodes D1 and D2 are connected in antiparallel to switching elements Q1 and Q2, respectively. Reactor L1 has one end connected to a connection node of switching elements Q1 and Q2, and the other end connected to positive line PL1.

  Converter 12 has the same configuration as converter 10. In the configuration of converter 10, switching elements Q1 and Q2 are replaced with switching elements Q3 and Q4, diodes D1 and D2 are replaced with diodes D3 and D4, respectively, and reactor L1 and positive line PL1 are replaced with reactor L2 and positive line PL2, respectively. The configuration corresponds to the configuration of the converter 12.

  Converters 10 and 12 are formed of a chopper circuit. Based on signal PWC1 (PWC2) from ECU 100 (FIG. 1), converter 10 (12) boosts the voltage of positive line PL1 (PL2) using reactor L1 (L2), and the boosted voltage is increased. Output to the power line PLM. Specifically, the step-up ratio of the output voltage from power storage devices B1 and B2 can be controlled by controlling the on / off period ratio (duty) of switching element Q1 (Q3) and / or switching element Q2 (Q4). .

  On the other hand, converter 10 (12) steps down the voltage of power line PLM based on signal PWC1 (PWC2) from ECU 100 (not shown), and outputs the stepped down voltage to positive line PL1 (PL2). Specifically, the step-down ratio of the voltage of power line PLM can be controlled by controlling the on / off period ratio (duty) of switching element Q1 (Q3) and / or switching element Q2 (Q4).

FIG. 3 is a first functional block diagram of ECU 100 shown in FIG.
Referring to FIG. 3, ECU 100 includes a converter control unit 200 and inverter control units 110 and 120. The function of each block shown in the following functional block diagrams including FIG. 3 is performed by software processing by execution of a predetermined program in the ECU 100 or hardware processing by a dedicated electronic circuit built in the ECU 100. It shall be realized.

  Converter control unit 200 turns on switching elements Q1 and Q2 of converter 10 based on voltage VB1 detected by voltage sensor 42, voltage VH detected by voltage sensor 46, and current IB1 detected by current sensor 52. Generates a PWM (Pulse Width Modulation) signal PWC1 for turning off. Converter control unit 200 generates shutdown signal SD1 for forcibly turning off switching elements Q1, Q2 when converter 10 is stopped.

  Similarly, converter control unit 200 turns on / off switching elements Q3, Q4 of converter 12 based on voltage VB2, voltage VH detected by voltage sensor 44, and current IB2 detected by current sensor 54. PWM signal PWC2 is generated. Converter control unit 200 generates shutdown signal SD2 for forcibly turning off switching elements Q3 and Q4 when converter 12 is stopped.

  Inverter control unit 110 generates a PWM signal for turning on / off a switching element included in inverter 20 based on torque command value TR1 of motor generator MG1, motor current MCRT1 and rotor rotation angle θ1, and voltage VH. The generated PWM signal is output to the inverter 20 as a signal PWI1.

  Converter control unit 200 further receives remaining capacities SOC1 and SOC2 which are respective remaining capacities (also referred to as SOC (State of Charge)) of power storage devices B1 and B2. For example, this remaining capacity is defined as 100% when the power storage device is fully charged, and is defined as 0% when the power storage device is completely discharged. The remaining capacity SOC1 (SOC2) can be calculated by various known methods using the voltage VB1 (VB2), the current IB1 (or IB2), the temperature T1 (or T2), and the like.

  Inverter control unit 120 generates a PWM signal for turning on / off a switching element included in inverter 22 based on torque command value TR2 of motor generator MG2, motor current MCRT2 and rotor rotation angle θ2, and voltage VH. The generated PWM signal is output to the inverter 22 as the signal PWI2.

  Torque command values TR1 and TR2 are calculated by a vehicle ECU (not shown) based on, for example, the accelerator opening, the brake depression amount, the vehicle speed, and the like. Motor currents MCRT1 and MCRT2 and rotor rotation angles θ1 and θ2 are detected by sensors (not shown).

  Next, charge / discharge control of power storage devices B1 and B2 by converters 10 and 12 will be described with reference to FIG.

  Referring to FIG. 4, converter control unit 200 (FIG. 3) includes a target value setting unit 210, a voltage control unit 215-1 and a current control unit 215-2. In the example of FIG. 4, converter 10 controls system voltage VH to target voltage VR by voltage control, while converter 12 controls charging / discharging current of corresponding power storage device B2 to target current IR by current control.

  Target value setting unit 210 includes torques of motor generators MG1 and MG2 (typically torque command values TR1 and TR2) and rotation speeds MRN1 and MRN2 (command values or detection values based on detection of rotation angles θ1 and θ2). Based on SOC1 and SOC2 of power storage devices B1 and B2, voltage-controlled converter target voltage VR and current-controlled converter target current IR are generated.

  Target value setting unit 210 applies system voltage VH according to torque command values TR1, TR2 and rotational speeds MRN1, MRN2 of motor generators MG1, MG2 during power running operation and regenerative braking of motor generators MG1 and / or MG2. Is set to an appropriate level. For example, target voltage VR is set such that system voltage VH is higher than the induced voltage at motor generators MG1, MG2.

  Referring to FIG. 4 again, voltage control unit 215-1 includes subtraction units 222-1 and 226-1, PI control unit 224-1 and modulation unit 228-1. Subtraction unit 222-1 subtracts system voltage VH from target voltage VR and outputs the calculation result to PI control unit 224-1. The PI control unit 224-1 performs a proportional integration calculation with the deviation between the target voltage VR and the system voltage VH as an input, and outputs the calculation result to the subtraction unit 226-1.

  Subtraction unit 226-1 subtracts the output of PI control unit 224-1 from the reciprocal of the theoretical boost ratio of converter 10 indicated by voltage VB1 / target voltage VR, and uses the calculation result as duty command Ton1 to modulation unit 228-1. Output to. Modulator 228-1 generates PWM signal PWC1 based on duty command Ton1 and a carrier wave (carrier wave) generated by an oscillating unit (not shown).

  Current control unit 215-2 includes subtraction units 222-2 and 226-2, PI control unit 224-2, and modulation unit 228-2. Subtraction unit 222-2 subtracts current IB2 from target current IR, and outputs the calculation result to PI control unit 224-2. The PI control unit 224-2 performs a proportional integration calculation with the deviation between the target current IR and the current IB2 as an input, and outputs the calculation result to the subtraction unit 226-2.

  Subtraction unit 226-2 subtracts the output of PI control unit 224-2 from the inverse of the theoretical boost ratio of converter 12 indicated by VB2 / VR, and outputs the calculation result to modulation unit 228-2 as duty command Ton2. . Modulation section 228-2 generates PWM signal PWC2 based on duty command Ton2 and a carrier wave (carrier wave) generated by an oscillation section (not shown).

  When the system voltage VH is lower than the target voltage VR and when the reciprocal of the theoretical boost ratio (VB1 / VR) is reduced, the voltage control unit 215-1 sets the on-period ratio of the lower arm element (Q2). The PWM signal PWC1 is generated so as to increase (or the OFF period ratio of the upper arm element (Q1) increases).

  On the other hand, current control unit 215-2 includes lower arm element (Q4) when output current IB2 from power storage device B2 is lower than target current IR and when the inverse of the theoretical boost ratio (VB2 / VR) increases. ) To generate the PWM signal PWC2.

  Note that the current control unit 215-2 has a current IB2 (IB2 <0) higher than the target current IR when the power storage device B2 is charged, that is, when the target current IR is set to a negative value (IR <0). When low (| IR | <| IB2 |, that is, when the charging current is excessive), the PWM signal PWC2 is generated so that the on-period ratio of the upper arm element (Q3) decreases. On the other hand, when the charging current is insufficient (when IR <IB2, that is, when | IR |> | IB2 |), the PWM signal PWC2 is generated so that the on-period ratio of the upper arm element (Q3) increases.

  With the control configuration shown in FIG. 4, voltage control of converter 10 and current control of converter 12 by switching (on / off) operation of upper arm elements Q1 and / or Q2 and lower arm elements Q3 and / or Q4, the system Voltage VH can be controlled to an appropriate level, and charge / discharge power of power storage devices B1 and B2 can be controlled.

  FIG. 4 shows a configuration example in which voltage control is executed by the converter 10 while current control is executed by the converter 12. However, in which converter the voltage control and current control are executed is switched. Is possible. For example, it is possible to switch the converter that performs voltage control / current control in accordance with the SOC of power storage devices B1, B2.

  Furthermore, the setting of the power target value for charge / discharge control of power storage devices B1 and B2 will be described using FIG.

  Referring to FIG. 5, target value setting unit 210 (FIG. 4) includes a battery power management unit 250. Battery power management unit 250 receives discharge power upper limit values Wout1, Wout2 (Wout1, Wout2 ≧ 0) and charge power upper limit values Win1, Win2 (Win1, Win2 ≦ 0), and SOC1, SOC2 of power storage devices B1, B2. For example, Win1 and Wout1 are set based on SOC1 and temperature T1, and Win2 and Wout2 are set based on SOC2 and temperature T2.

  Further, the battery power management unit 250 is configured to supply power from the power supply system to the load device based on the state comparison of the power storage devices B1 and B2 represented by the SOC1 and SOC2, for example, by the same method as described in Patent Document 2. The discharge power distribution ratio between the power storage devices B1 and B2 and the charge power distribution ratio between the power storage devices B1 and B2 when the power supply system is charged with the power from the load device are calculated. In the following, it is assumed that the discharge power distribution ratio (or charge power distribution ratio) is indicated by the ratio k of the discharge power (or charge power) of power storage device B2 to the discharge power (or charge power) from power storage device B1.

  Battery power management unit 250 sets power target values Pb1 and Pb2 of power storage devices B1 and B2 according to the required power PR for the power supply system and the ratio k. That is, Pb1 = PR / (1 + k) and Pb2 = k · Pb1 = k / (1 + k) · PR are set. When power is output from the power supply system where PR> 0, Pb1, Pb2 ≧ 0, and the power target values Pb1, Pb2 correspond to “output power target values”. Further, when charging the power supply system where PR <0, Pb1, Pb2 ≦ 0, and the power target values Pb1, Pb2 correspond to “input power target values”.

  Here, as described in FIG. 4, converter 10 corresponding to power storage device B1 performs voltage control, while converter 12 for power storage device B2 controls the input / output current of power storage device B2. That is, by setting the target current IR of converter 12 to IR = Pb2 / VR, the charge / discharge power of power storage device B2 can be controlled to power target value Pb2. Further, since the charge / discharge power of the remaining power storage device B1 is Pb1 = PR−Pb2, it is possible to control to the power target value Pb1 by charging / discharging with the remaining power.

  Thus, battery power management unit 250 basically sets power target values Pb1 and Pb2 of power storage devices B1 and B2 according to discharge (charging) distribution ratio k based on the states of power storage devices B1 and B2. To do.

  Next, the setting of the power consumption upper limit power value of motor generator MG2 in the load device as part of the power balance control in the entire hybrid vehicle 1000 will be described.

  A vehicle ECU (not shown) that integrally controls the entire hybrid vehicle 1000 calculates the required power of the entire hybrid vehicle 1000 that reflects the pedal operation by the user, and the output power of the engine 2 and the motor with respect to the total required power. Control is performed so that the distribution with the generated power of generators MG1 and MG2 is optimum. Then, torque command values TR1 and TR2 are calculated according to this power distribution, and the required power PR of the power supply system is set. Therefore, by appropriately setting the power consumption upper limit value of motor generator MG2 that is a power source at the time of the power distribution, it is possible to avoid requesting excessive discharge to the power supply system.

  For this purpose, ECU 100 sets a consumption upper limit power value (hereinafter also referred to as MG2 upper limit power) Pmg2max of motor generator MG2 as follows.

  FIG. 6 is a functional block diagram showing a control configuration related to setting of MG2 upper limit power Pmg2max in the electric power balance control of hybrid vehicle 1000 by ECU 100 as a whole.

  Referring to FIG. 6, MG1 power calculation unit 310 calculates MG1 power Pmg1 input / output from motor generator MG1 based on torque command value TR1 and rotation speed MRN1 of motor generator MG1. When power is generated by motor generator MG1, Pmg1 <0.

Capacitor boost power calculation unit 320 calculates capacitor boost power Pc indicating the amount of increase in stored energy of capacitor C due to change in system voltage VH. That is, capacitor boost power Pc is calculated according to Pc = ΔVH ² / C according to voltage increase amount ΔVH when system voltage VH increases.

  In addition to capacitor boost power Pc from capacitor boost power calculation unit 320 and MG1 power Pmg1 from MG1 power calculation unit 310, power balance management unit 350 calculates rotation speed MR2 of motor generator MG2 for calculating engine direct power. Further receives torque command value TR1. Furthermore, power balance management unit 350 receives discharge power upper limit values Wout1 and Wout2 of power storage devices B1 and B2 and power target value Pb2 of power storage device B2.

  Here, the direct power corresponds to a component of the output power of the engine 2 that acts as the drive power of the motor generator MG2 via the power split mechanism 4. That is, the direct power PD can be calculated according to the product of the direct torque that is the direct torque from the engine 2 and the rotational speed MR2. Here, the direct torque can be obtained by the product of the torque command value TR1 of MG1 and a predetermined gear ratio according to the nomograph according to the power split mechanism 4. That is, it can be calculated by PD = TR1 · (gear ratio) · MR2.

  Using these parameters, power balance management unit 350 sets MG2 upper limit power Pmg2max according to the following equation (1). In equation (1), m represents a predetermined margin amount, and POmax represents an upper limit power that can be output from the power supply system.

Pmg2max = POmax−Pmg1−Pc + PD + m (1)
In this way, MG2 upper limit power Pmg2max can be set reflecting the output upper limit power POmax of the power supply system while taking into consideration the operating states of motor generator MG1 and engine 2.

  From the MG2 upper limit power Pmg2max set in this way and the rotational speed of the motor generator MG2, the upper limit value of the torque command value TR2 can be set. For example, when the power distribution is executed so that the drive torque required for the entire hybrid vehicle 1000 can be obtained, the upper limit value of the torque command value TR2 is set as described above, so that the required power PR to the power supply system is set. Is prevented from exceeding output upper limit power POmax, and motor generator MG2 can be driven.

  In the present embodiment, power balance management unit 350 is a power supply system that is used to calculate MG2 upper limit power Pmg2max according to driving force request flag FDV that is turned on / off in response to an output request to load device (motor generator MG2). The setting of the output upper limit power POmax is switched.

  For example, the driving force request flag FDV is turned on when the vehicle acceleration request is high based on the accelerator pedal operation by the driver, specifically, the accelerator opening or the accelerator pedal depression speed, while Sometimes it can be turned off. Alternatively, on / off of the driving force request flag FDV may be controlled by combining the accelerator pedal operation and the running state (road gradient or the like). In general, the driving force request flag FDV is turned on when a high output request is made to the load device (motor generator MG2).

  At normal time when driving force request flag FDV is turned off, output upper limit power POmax is set according to the sum of discharge power upper limit value Wout1 of power storage device B1 and power target value Pb2 of power storage device B2. On the other hand, at the time of a high output request when driving force request flag FDV is turned on, output upper limit power POmax of the power supply system is set according to the sum of discharge power upper limit values Wout1 and Wout2 of power storage devices B1 and B2.

  FIG. 7 schematically shows changes in setting of power target values Pb1 and Pb2 of power storage devices B1 and B2 due to switching of output upper limit power POmax as described above. FIG. 7A shows the setting of power target values Pb1 and Pb2 at the normal time when the driving force request flag FDV is turned off, while FIG. 7B shows that the driving force request flag FDV is turned on. The setting of power target values Pb1 and Pb2 at the time of a high output request is shown.

  As shown in FIG. 7A, during normal times, the power target values Pb1 and Pb2 are set with priority given to maintaining the discharge power distribution ratio k (Pb2 / Pb1). Therefore, output upper limit power POmax of the power supply system follows the sum of discharge power upper limit value Wout1 of power storage device B1 and power target value Pb2 (= Wout1 · k) at this time. Therefore, when the discharge upper limit powers of power storage devices B1 and B2 are equal by the charge / discharge control according to the discharge power distribution ratio k (Wout1≈Wout2), there is a surplus power in the output power of power storage device B2. (That is, Pb2 <Wout2), the output upper limit power POmax may be set.

  On the other hand, as shown in FIG. 7 (b), at the time of a high output request in which the driving force request flag FDV is turned on, priority is given to an increase in the output power from the power supply system over the maintenance of the discharge power distribution ratio k. Output upper limit power POmax is set according to the sum of discharge power upper limit values Wout1, Wout2 of power storage devices B1, B2. In this case, according to the discharge power distribution ratio k, there is a possibility that Pb1> Wout1. Therefore, while maintaining Pb1 ≦ Wout1, the excess power (Pb1-Wout) is set to the power target value Pb2. The power target value Pb2 is set so as to be added.

  At this time, it is necessary to reset the power target values Pb1 and Pb2 in order to correct the setting of the power target value according to the discharge power distribution ratio k described in FIG. As a result, the reset discharge power ratio (Pb2 / Pb1) after resetting is higher than the initial discharge power distribution ratio k. As a result, when the driving force request flag FDV is on, the output upper limit power POmax of the power supply system can be increased from the normal time to meet a high output request to the load device.

  Referring to FIG. 6 again, power balance management unit 350 calculates MG2 upper limit power Pmg2max according to the equation (1) where POmax = Wout1 + Wout2 as described above when driving force request flag FDV is on, and battery power Resetting request RQAG for power target values Pb1, Pb2 of power storage devices B1, B2 is generated for management unit 250.

  Referring to FIG. 5 again, when battery power management unit 250 receives reset request RQAG from power balance management unit 350, as shown in FIG. 7B, output upper limit power POmax = Wout1 + Wout2 of the power supply system. Then, the power target values Pb1 and Pb2 are set again so that the power target values Pb1 and Pb2 do not exceed Wout1 and Wout2 and Pb1 + Pb2 = PR, respectively, for the set required power PR.

  FIGS. 8 and 9 are flowcharts illustrating a control processing procedure for realizing the power balance control described with reference to FIGS. Each step of the flowcharts shown in FIGS. 8 and 9 can also be realized by software processing or hardware processing by the ECU 100.

FIG. 8 shows a procedure for setting the MG2 upper limit power.
Referring to FIG. 8, ECU 100 confirms whether or not driving force request flag FDV is turned on in step S100. In the normal time when the driving force request flag FDV is turned off (NO in S100), the ECU 100 proceeds to step S120 and calculates the MG2 upper limit power based on normal power management (power distribution). To do. That is, as shown in FIG. 7A, the MG2 upper limit power Pmg2max is calculated such that the output power of the power supply system is set within the range of Pb1 ≦ Wout1 and Pb2 ≦ Wout1 · k.

  On the other hand, at the time of high output request when the driving force request flag is turned on (YES determination at S100), the ECU 100 proceeds to step S110 and resets the power distribution as shown in FIG. 7B. , The MG2 upper limit power Pmg2max is calculated so that the output power of the power supply system is set within the range of Pb1 ≦ Wout1 and Pb2 ≦ Wout2. As described above, when the power distribution is reset, the discharge power distribution ratio indicated by Pb2 / Pb1 is larger than the original distribution ratio k in step S120.

  FIG. 9 shows a setting processing procedure of power target values Pb1 and Pb2 of power storage devices B1 and B2 including a response to a power distribution resetting request when power is supplied from the power supply system to the load.

  Referring to FIG. 9, ECU 100 sets charging power upper limit values Win1, Win2 and discharging power upper limit values Wout1, Wout2 based on the state (battery state) of power storage devices B1, B2 in step S200. For example, the process of step S200 is realized by referring to a map created in advance based on the combination of SOCs of power storage devices B1 and B2 and temperatures T1 and T2.

  In step S210, ECU 100 determines discharge power distribution ratio k (k = Pb2 / Pb1) by comparing the states of power storage devices B1 and B2, and in step S220, the required power PR for the power supply system is set in step S210. Power target values Pb1 and Pb2 of power storage devices B1 and B2 are determined from the discharged power distribution rate k.

  Further, in step S230, ECU 100 determines whether or not a power distribution resetting request is generated in association with turning on of driving force request flag FDV. Then, when the reset request is not generated (NO determination in S230), ECU 100 proceeds to step S240 and sets target power values Pb1, Pb2 according to discharge power distribution ratio k set in step S220. To maintain.

  On the other hand, when a reset request is generated (YES in S230), ECU 100 proceeds to step S250 and discharge power after setting MG2 upper limit power Pmg2max based on the sum of discharge power upper limit values Wout1 and Wout2. The power target values Pb1 and Pb2 are recalculated using the value (required power PR).

  In step S260, ECU 100 controls power storage devices B1, B2 according to power target values Pb1, Pb2 finally determined in step S240 or S250. Specifically, target current IR for current control by converter 12 corresponding to power storage device B2 is set according to power target value Pb2 of power storage device B2. Then, since the discharge power of power storage device B1 becomes a remainder obtained by subtracting the discharge power of power storage device B2 from the output power from the power supply system, it is automatically controlled according to power target value Pb1 (Pb1 = PR−Pb2). It will be.

  As described above, according to the present embodiment, during normal times, the output power from power storage devices B1 and B2 is controlled according to the discharge power distribution ratio, while at the time of a high output request by an accelerator pedal operation or the like, power storage devices B1 and B2 The output power to the load device including motor generator MG2 can be expanded to the upper limit power according to the sum of the discharge power upper limit values (Wout1 + Wout2). Therefore, while the plurality of power storage devices B1 and B2 are normally used in a balanced manner, when the demand for output to the load device increases, it is maximized within the range of allowable discharge power of the plurality of power storage devices B1 and B2 as a whole. It can meet the output demand. As a result, the power supply system can be fully utilized.

(Application to charge control)
In the above description, the power output from the power supply system, that is, the discharge of power storage devices B1 and B2, has been described. However, the present embodiment is modified to input power to the power supply system, that is, power storage device B1. , B2 can also be applied during charging.

  When power is input to the power supply system, the required power PR and the power target values Pb1, Pb2 are negative values, and the MG2 upper limit power Pmg2max is also a negative value that defines the upper limit value of the regenerative power generation power. In normal times, power target values Pb1 and Pb2 are set according to the above-described charge power distribution ratio and required power PR (<0), and MG2 upper limit power Pmg2max is also calculated based on Win1 + k · Win1. Thus, charging is controlled so that the plurality of power storage devices B1 and B2 are used in a balanced manner.

  On the other hand, when the regenerative braking request by the motor generator MG2, that is, the power generation request to the motor generator MG2, is increased by the brake pedal operation or the traveling road gradient (steep descent), the input power is more than the maintenance of the charge power distribution ratio MG2 upper limit power Pmg2max is calculated based on Win1 + Wout2. The power target values Pb1 and Pb2 are also reset for correcting the setting according to the charge power distribution rate.

  Specifically, instead of the driving force request flag, a power generation request flag that is turned on when the power generation request to the motor generator MG2 as described above is increased, and Wout1 and Wout2 are appropriately replaced with Win1, Win2 By executing the processing replaced with MG2, the battery power management unit 250 and the power balance management unit 350 can also charge the power storage devices B1 and B2 in the same way as during the above-described discharging, in the same manner as in the above-described discharging. Pb1 and Pb2 can be set.

  In the flowchart of FIG. 8, in step S100, it is determined whether the power generation request flag is on or off. In steps S110 and S120, the discharge power distribution ratio is replaced with the charge power distribution ratio, and Wout1 and Wout2 are replaced with Win1 and Wout2. Accordingly, the MG2 upper limit power Pmg2max can be set similarly to the above-described discharge. Further, in the flowchart of FIG. 8, the charging power distribution values and the power target values Pb1 and Pb2 based on these values are calculated in steps S210 and S220, and in step S250, the power is replaced by replacing Wout1 and Wout2 with Win1 and Wout2. The target values Pb1 and Pb2 can be reset. As a result, the charging control according to the present embodiment can be executed in step S260.

(Modification of power system configuration)
In the embodiment described above, the power storage system provided with the power storage devices B1 and B2 and the converters 10 and 12 corresponding to the power storage devices B1 and B2, respectively, that is, provided with two sets of power storage devices and converters has been described. Is not limited to such a configuration.

  That is, as shown in FIG. 10, the charge / discharge control according to the present embodiment can also be applied to a power supply system having a configuration in which three or more sets of power storage devices and corresponding converters are connected in parallel. When there are three or more power storage devices, voltage control may be performed by any one converter and current control may be performed by the remaining converters.

  Instead of the hybrid vehicle 1000, the present invention can also be applied to an electric vehicle not equipped with an internal combustion engine, and a fuel cell vehicle further equipped with a fuel cell that generates electric energy using fuel. Further, the load device is not limited to an electric motor (motor generator) for generating vehicle driving force, and a power supply system applied to other load devices includes a plurality of sets of power storage devices and converters (power conversion devices). If it is a structure, application of this invention is possible.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is an overall block diagram of a hybrid vehicle shown as an example of an electric vehicle equipped with a power supply system according to the present embodiment. It is a circuit diagram which shows the structure of the converters 10 and 12 shown in FIG. FIG. 2 is a first functional block diagram of ECU 100 shown in FIG. 1. It is a functional block diagram explaining charging / discharging control of the electrical storage apparatus by a converter. It is a functional block diagram explaining the setting of the electric power target value for charging / discharging control of electrical storage apparatus B1, B2. FIG. 2 is a functional block diagram showing a control configuration relating to setting of a consumption upper limit power value in a motor generator as part of power balance control in the entire hybrid vehicle shown in FIG. 1. It is a conceptual diagram explaining switching of the output upper limit electric power of a power supply system accompanying ON / OFF of a driving force flag. It is a flowchart explaining the setting process sequence of MG2 upper limit power in the power supply system by this Embodiment. It is a flowchart explaining the setting process sequence of the electric power target value of each electrical storage apparatus at the time of the electric power supply to the load from the power supply system in the power supply system by this Embodiment. It is a block diagram which shows the modification of a structure of the power supply system by this Embodiment.

Explanation of symbols

  2 engine, 4 power split mechanism, 6 wheels, 10, 12 converter, 20, 22 inverter, 42, 44, 46 voltage sensor, 52, 54 current sensor, 62, 64 temperature sensor, 110, 120 inverter control unit, 200 converter Control unit, 210 Target value setting unit, 215-1 Voltage control unit, 215-2 Current control unit, 222-1, 222-2, 226-1, 226-2 Subtraction unit, 224-1, 224-2 PI control Unit, 228-1, 228-2 modulation unit, 250 battery power management unit, 310 MG1 power calculation unit, 320 capacitor boost power calculation unit, 350 power balance management unit, 1000 hybrid vehicle, B1, B2 power storage device, C capacitor, D1-D4 diode, FDV power request flag, IB1, IB2 current (power storage device) , IR target current, k discharge power distribution ratio, L1, L2 reactor, MCRT1, MCRT2 motor current, MG1, MG2 motor generator, MR1, MR2 rotational speed (MG1, MG2), NL power line, Pb1, Pb2 power target value, Pc Capacitor boost power, PD direct power, PL1, PL2 positive line, PLM, PLN power line, Pmg1 MG1 power, Pmg2max MG2 upper limit power, POmax output upper limit power (power supply system), PR required power, PWC1, PWC2, PWI1, PWI2 signal, Q1-Q4 Power semiconductor switching element, RQAG reset request, SD1, SD2 shutdown signal, SOC1, SOC2 remaining capacity, T1, T2 temperature (power storage device), Ton1, Ton2 duty command, TR1 , TR2 Torque command value, VB1, VB2 voltage (power storage device), VH DC voltage (system voltage), VR target voltage, Win1, Win2 charge power upper limit value, Wout1, Wout2 discharge power upper limit value, θ1, θ2 rotor rotation angle.

Claims (8)

A power supply system for supplying power to a load device,
A power line connected to the load device;
A plurality of power storage devices;
The power lines are arranged between the power lines and the plurality of power storage devices, respectively, and are configured to control power conversion between the plurality of power storage devices and the power lines based on output power target values of the power storage devices. A plurality of first power converters;
Based on a comparison of the states of the plurality of power storage devices, setting a discharge power distribution ratio among the plurality of power storage devices when power is supplied to the load device, and output required power to the power supply system and the discharge power A power storage device power management unit that sets the output power target value of each power storage device according to a distribution ratio;
A power balance management unit for setting a power consumption upper limit power value of the load device for limiting the output required power,
The power balance management unit selects one of the first and second modes based on an output request to the load device, and when selecting the first mode, a predetermined one of the plurality of power storage devices is selected. The sum of the discharge power upper limit value of the power storage device and the maximum value of the output power target value of each of the remaining power storage devices according to the product of the discharge power upper limit value and the discharge power distribution ratio is the output upper limit power of the power supply system. While setting the consumption upper limit power value, when selecting the second mode, the consumption upper limit power value is set with the sum of the discharge power upper limit values of each power storage device as the output upper limit power,
The power balance management unit maintains the output power target value set in accordance with the discharge power distribution ratio when the first mode is selected, and from each power storage device when the second mode is selected. A power supply system that resets the output power target value of each power storage device within a range in which the output power does not exceed the corresponding discharge power upper limit value. The plurality of first power converters further control power conversion between the plurality of power storage devices and the power line based on an input power target value of each power storage device during power generation of the load device. Configured as
The power storage device power management unit further sets a charge power distribution ratio among the plurality of power storage devices when receiving power from the load device based on a state comparison of the plurality of power storage devices, and the power source Setting the input power target value of each power storage device according to the required power input to the system and the charge power distribution ratio;
The power balance management unit selects one of the third and fourth modes based on a power generation request to the load device during power generation of the load device, and selects the plurality of modes when selecting the third mode. The sum of the charging power upper limit value of a predetermined power storage device of the power storage devices and the maximum value of the input power target value of each of the remaining power storage devices according to the product of the charging power upper limit value and the charging power distribution ratio. While setting the power generation upper limit power value of the load device for limiting the input required power as the input upper limit power of the power supply system, when the fourth mode is selected, the charging power upper limit value of each power storage device The power generation upper limit power value is set using the sum of the above as the input upper limit power,
The power balance management unit maintains the input power target value set in accordance with the charge power distribution ratio when the third mode is selected, while each power storage device is selected when the fourth mode is selected. 2. The power supply system according to claim 1, wherein the input power target value of each of the power storage devices is reset within a range in which the input power does not exceed the corresponding charging power upper limit value. The power supply system and the load device are mounted on an electric vehicle,
The load device is:
A rotating electrical machine arranged to be able to transmit power to and from drive wheels of the electric vehicle;
A second power converter configured to control power conversion between the rotating electrical machine and the power line so that the rotating electrical machine outputs a torque according to a torque command value;
The power supply system according to claim 1, wherein the power balance management unit selects one of the first and second modes based on an operation of an accelerator pedal. The consumption upper limit power value of the load device indicates the consumption upper limit power value of the rotating electrical machine,
The power supply system according to claim 3, wherein a torque upper limit value of the rotating electric machine is set based on a rotation speed of the rotating electric machine and the consumption upper limit power value. A power line connected to the load device, a plurality of power storage devices, and the power line and the plurality of power storage devices, respectively, and based on an output power target value of each power storage device, the plurality of power storage devices and the A power balance control method for a power supply system comprising a plurality of first power converters configured to control power conversion to and from a power line, comprising:
Setting a discharge power upper limit value for each of the plurality of power storage devices based on the state of each of the plurality of power storage devices;
Based on a state comparison of the plurality of power storage devices, setting a discharge power distribution ratio among the plurality of power storage devices during power supply to the load device;
Setting an output power target value for each of the power storage devices according to the required output power to the power supply system and the discharge power distribution ratio;
Selecting one of the first and second modes based on an output request to the load device;
Each of the remaining power storage devices according to the product of the discharge power upper limit value of the predetermined power storage device of the plurality of power storage devices and the discharge power upper limit value and the discharge power distribution ratio when the first mode is selected. Setting a power consumption upper limit power value of the load device for limiting the output required power so that the output upper limit power of the power supply system is the sum of the output power target value and the maximum value of
Setting the consumption upper limit power value so that the sum of the discharge power upper limit values of the power storage devices is set as the output upper limit power when the second mode is selected;
Maintaining the output power target value set according to the discharge power distribution ratio when selecting the first mode;
Re-setting the output power target value of each power storage device within a range in which the output power from each power storage device does not exceed the corresponding discharge power upper limit value when selecting the second mode. , Power balance control method of power system. The plurality of first power converters further control power conversion between the plurality of power storage devices and the power line based on an input power target value of each power storage device during power generation of the load device. Configured as
Setting a charging power upper limit value of each of the plurality of power storage devices based on the state of each of the plurality of power storage devices;
Setting a charging power distribution ratio among the plurality of power storage devices when receiving power from the load device;
Setting an input power target value for each of the power storage devices according to the input required power to the power supply system and the charge power distribution ratio;
Selecting one of the third and fourth modes based on a power generation request to the load device;
Each of the remaining power storage devices according to the product of the charge power upper limit value of the predetermined power storage device of the plurality of power storage devices and the charge power upper limit value and the charge power distribution ratio when the third mode is selected. Setting the power generation upper limit power value of the load device for limiting the input required power so that the sum of the input power target value and the maximum value of the input power is the input upper limit power of the power supply system;
Setting the power generation upper limit power value so that the sum of the charging power upper limit values of the respective power storage devices is set as the input upper limit power when the fourth mode is selected;
Maintaining the input power target value set according to the charge power distribution ratio when selecting the third mode;
Re-setting the input power target value of each power storage device within a range in which the input power to each power storage device does not exceed the corresponding charge power upper limit value when selecting the fourth mode; A power balance control method for a power supply system according to claim 5. The power supply system and the load device are mounted on an electric vehicle,
The load device is:
A rotating electrical machine arranged to be able to transmit power to and from drive wheels of the electric vehicle;
A second power converter configured to control power conversion between the rotating electrical machine and the power line so that the rotating electrical machine outputs a torque according to a torque command value;
6. The power balance control method for a power supply system according to claim 5, wherein the selecting step selects one of the first mode and the second mode based on an operation of an accelerator pedal. The consumption upper limit power value of the load device indicates the consumption upper limit power value of the rotating electrical machine,
The power balance control method for a power supply system according to claim 7, wherein a torque upper limit value of the rotating electrical machine is set based on a rotation speed of the rotating electrical machine and the consumption upper limit power value.

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