JP2009060759A - Power supply system and charge control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress AC components in a charging current in an electricity storage device, in a power supply system having a constitution in which AC power from an AC power supply outside an electric vehicle is converted into DC power, to charge the electricity storage device. <P>SOLUTION: In a converter control part 205, a voltage Vh on a power line to which a DC voltage converted from the AC power from an external power supply is controlled to a target voltage Vhr. In a voltage-control part 210a, the basic amount β0 of a voltage conversion ratio β of a converter is obtained, based on the input voltage Vb of the converter, the voltage Vh and the target voltage Vhr. In a voltage-smoothing control part 210b, the correction amount βc of the voltage conversion ratio β required for changing the voltage Vh is set so as to suppress a voltage fluctuation Vlac generated by fluctuations in the charging current. In a modulation part 270, switching control signals S1, S2 are generated so that the duty ratio of a semiconductor switching element, constituting the converter, conforms to the voltage conversion ratio β, based on the sum of the basic amount β0 and the correction amount βc. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply system and a charge control method thereof, and more specifically, charge control of a power storage device in a power supply system mounted on an electric vehicle capable of generating a driving force using electric power stored in the power storage device. About.

  Electric vehicles equipped with an electric motor as a driving force source such as a hybrid vehicle and an electric vehicle are widely used. In such an electric vehicle, a method of improving fuel consumption is generally used by using the electric power generated by the electric motor during regenerative braking as the charging electric power of the power storage device during vehicle operation.

  Furthermore, in recent years, a configuration has been proposed for such an electric vehicle in which the power storage device is charged by an external power source during parking after the operation is stopped. For example, Japanese Patent No. 2695083 (Patent Document 1) discloses an electric motor drive capable of operating so as to supply electric power from a power source external to a vehicle connected to an input / output port to a storage battery mounted on the vehicle. And a power processor. According to the configuration of Patent Document 1, a storage battery mounted on a vehicle by converting AC power to DC power from a single-phase power source in which an input / output port is connected to a neutral point of a motor winding via an EMI filter is provided. It is possible to charge.

  JP-A-8-126121 (Patent Document 2) is mounted on a vehicle by connecting an external power source to the neutral point of two vehicle-driven permanent magnet motors and using the motor coils as reactors. An on-vehicle charging device for an electric vehicle that generates charging power for a battery is disclosed.

In Japanese Patent Laid-Open No. 5-207664 (Patent Document 3), a motor drive power converter is provided with bidirectional power conversion characteristics, and AC or DC power is supplied from the outside for charging a storage battery of an electric vehicle. In addition, a configuration in which step-up charging or step-down charging is performed in combination with chopper control of a power converter is disclosed. At this time, the winding of the AC motor is used as a reactor necessary for chopper control.
Japanese Patent No. 2695083 JP-A-8-126121 JP-A-5-207664

  When charging a DC power source (typically a secondary battery) mounted on a vehicle with an AC power source outside the vehicle, it is necessary to convert the AC power from the external power source into DC power for charging the secondary battery. is there. At this time, in the DC power obtained by converting AC power, a ripple component that fluctuates at a frequency related to the power supply frequency (for example, twice the power supply frequency) may be superimposed on the DC voltage and DC current.

  For this reason, in external charging in a cryogenic environment, the charging current of the secondary battery varies depending on the ripple component, so that the terminal voltage of the secondary battery varies accordingly. The battery voltage may reach an overvoltage level and charging may not be continued. On the other hand, if the average value (effective value) of the charging current is lowered in order to avoid such a phenomenon, the amount of charge per unit time is lowered, so that the charging time becomes longer.

  Furthermore, when a reactor as a converter component or the like is connected to the charging path of the power storage device, an alternating current of a ripple component always flows through the reactor, so that charging efficiency is reduced due to generation of reactive power.

  The present invention has been made to solve such a problem, and an object of the present invention is to convert an AC power from an AC power source outside the vehicle into a DC power and install the power storage device mounted on the vehicle. In the power supply system configured to be charged, efficient charging is performed by suppressing the AC component of the charging current of the power storage device.

  An electric vehicle according to the present invention is a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line, and is a chargeable / dischargeable power storage device, a converter, a voltage detector, and a control A device and a charging power conversion device. The converter is connected between the power line and the power storage device, and is configured to include a plurality of power semiconductor switching elements so as to perform DC voltage conversion bidirectionally between the power storage device and the power line. The voltage detector detects the voltage of the power line. The control device controls on / off of each power semiconductor switching element of the converter so as to maintain the voltage of the power line at the target voltage. The charging power conversion device converts an AC voltage from the external power source into a DC voltage on which a frequency component related to the frequency of the AC voltage is superimposed and outputs to the power line in a charging mode in which the electric vehicle is connected to the external power source. To do. The control device includes a voltage control unit, a current smoothing control unit, and a modulation unit. The voltage control unit sets a basic amount of the voltage conversion ratio by the converter based on the target voltage, the detection voltage by the voltage detector, and the output voltage of the power storage device. In the charging mode, the current smoothing control unit sets the correction amount of the voltage conversion ratio so as to change the voltage on the power line so as to cancel the current fluctuation corresponding to the frequency component superimposed on the charging current of the power storage device. The modulation unit generates a signal for controlling on / off of the plurality of power semiconductor switching elements based on the voltage conversion ratio according to the sum of the basic amount and the correction amount.

  In the power supply system charging control method according to the present invention, the power supply system includes a chargeable / dischargeable power storage device, a converter, a voltage detector, a control device, and a charge power conversion device. The converter is connected between the power line and the power storage device, and is configured to include a plurality of power semiconductor switching elements so as to perform DC voltage conversion bidirectionally between the power storage device and the power line. The voltage detector detects the voltage of the power line. The control device controls on / off of each power semiconductor switching element of the converter so that the voltage of the power line is maintained at the target voltage. The charging power conversion device converts an AC voltage from the external power source into a DC voltage on which a frequency component related to the frequency of the AC voltage is superimposed and outputs to the power line in a charging mode in which the electric vehicle is connected to the external power source. To do. The control method includes a step of calculating a basic amount of a voltage conversion ratio by a converter based on a target voltage, a detection voltage by a voltage detector, and an output voltage of the power storage device, and charging the power storage device in a charge mode. The step of calculating the correction amount of the voltage conversion ratio so as to change the voltage on the power line so as to cancel the current fluctuation corresponding to the frequency component superimposed on the current, and the voltage conversion ratio according to the sum of the basic amount and the correction amount And generating a signal for controlling on / off of the plurality of power semiconductor switching elements.

  According to the power supply system and the control method for the power supply system, charging is performed so as to cancel the current fluctuation (AC component) of the charging current of the power storage device caused by the AC component of the DC voltage converted from the AC voltage from the external power supply. The voltage of the power line from which the DC voltage is output from the power converter can be changed by correcting the voltage conversion ratio controlled by the converter. As a result, charging failure due to fluctuations in the terminal voltage of the power storage device due to fluctuations in charging current, and prolonged charging time by suppressing the average value (effective value) of charging current to avoid the charging failure Can be prevented.

  Preferably, the converter further includes a reactor electrically connected between the power line and the power storage device via one of the plurality of power semiconductor switching elements. Furthermore, the current smoothing control unit includes a voltage estimation unit, a frequency filter unit, and a control calculation unit. The voltage estimation unit estimates the voltage of the reactor based on the detection voltage by the voltage detector, the voltage conversion ratio determined by the voltage control unit and the current smoothing control unit, and the output voltage of the power storage device. A frequency filter part extracts the voltage fluctuation corresponding to a frequency component from the reactor voltage estimated by the voltage estimation part. The control calculation unit obtains a correction amount of the voltage conversion ratio for changing the voltage on the power line so as to cancel the voltage fluctuation extracted by the frequency filter unit. Alternatively, the step of calculating the correction amount includes the sub-step of estimating the reactor voltage based on the detection voltage by the voltage detector, the voltage conversion ratio, and the output voltage of the power storage device, and the estimated reactor voltage. A sub-step for extracting a voltage fluctuation corresponding to the frequency component; and a sub-step for performing a control calculation for obtaining a correction amount of the voltage conversion ratio for changing the voltage on the power line so as to cancel the extracted voltage fluctuation. .

  By setting it as such a structure, the electric current fluctuation | variation (alternating current component) of the charging current of an electrical storage apparatus can be indirectly detected based on the voltage fluctuation of the reactor arrange | positioned in a converter. For this reason, converter control which suppresses the current fluctuation of the charging current of the power storage device can be realized without using the value of the current sensor provided in the power storage device. Thus, for example, in a vehicle layout in which the power storage device and the converter are spaced apart from each other, it is possible to execute the converter control while avoiding the occurrence of a control error due to the transmission delay of the current sensor value. Furthermore, since the AC component of the DC current that flows during charging of the reactor in the converter is suppressed, the power conversion efficiency in the converter can be improved.

  Preferably, the power supply system further includes a current detector for detecting an input / output current of the power storage device. The current smoothing control unit includes a frequency filter unit and a control calculation unit. Current fluctuation is extracted from the charging current detected by the current detector in the frequency filter section and the charging mode. The control calculation unit obtains a correction amount of the voltage conversion ratio for changing the voltage on the power line so as to cancel the current fluctuation extracted by the frequency filter unit. Alternatively, the step of calculating the correction amount includes a sub-step for extracting current fluctuation from the charging current detected by the current detector and a voltage on the power line so as to cancel the extracted current fluctuation in the charging mode. Performing a control operation for obtaining a correction amount of the voltage conversion ratio.

  By adopting such a configuration, it is possible to more accurately execute converter control for suppressing current fluctuation (AC component) of the charging current based on the detected value of the charging current of the power storage device. This configuration is suitable for a vehicle layout in which a current detector for detecting a charging current and a converter control device are arranged relatively close to each other.

  More preferably, the electric vehicle includes a first AC rotating electric machine including a star-connected first multi-phase winding as a stator winding, and a star-connected second multi-phase winding as a stator. And a second AC rotating electric machine included as a winding. The power supply system further includes first and second inverters, an inverter control device that controls on / off of the power semiconductor switching elements of the first and second inverters, and a connector unit. The first inverter is connected to the first multiphase winding and performs power conversion between the first AC rotating electric machine and the power line. The second inverter is connected to the second multiphase winding and performs power conversion between the second AC rotating electric machine and the power line. The connector portion electrically connects between the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding and the external power source in the charging mode. . Furthermore, at least one of the first and second AC rotating electric machines is used for generating a driving force. In the charging mode, the inverter control device operates as the charging power conversion device by operating the first and second inverters and the inductances of the first and second multiphase windings via the connector portion. Each of the first and second inverters is controlled so that the AC voltage from the external power source supplied to the first and second neutral points is converted into a DC voltage and output to the power line.

  With such a configuration, the first and second AC rotating electric machines and the first and second inverters used for generating the driving force are supplied from an external power source without providing new equipment. In a vehicle configuration that can convert electric power into a charging current for a power storage device, the AC component of the charging current for the power storage device can be reduced by converter control.

  According to this invention, in a power supply system configured to convert AC power from an AC power supply outside the vehicle into DC power and charge the power storage device mounted on the vehicle, the AC component of the charging current of the power storage device is suppressed. , Efficient charging can be performed.

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

  FIG. 1 is a circuit diagram showing the overall configuration of an electric vehicle equipped with a power supply system according to an embodiment of the present invention.

  Referring to FIG. 1, electrically powered vehicle 100 includes a power storage device 10, a converter 20, a smoothing capacitor C1, inverters 30-1 and 30-2, motor generators MG1 and MG2, and a control device 200.

  Since the power storage device 10 is typically constituted by a secondary battery such as a nickel hydride secondary battery or a lithium ion secondary battery, the power storage device 10 is also simply referred to as a secondary battery or a battery. However, it will be described in a confirming manner that a power storage device other than the secondary battery, such as an electric double layer capacitor, can be applied in place of the secondary battery 10.

  The secondary battery 10 is provided with at least a current sensor 106. The current sensor 106 detects the input / output current Ib of the secondary battery 10. In the following, it is assumed that Ib> 0 when the secondary battery 10 is discharged and Ib <0 when charging. The detected current Ib is transmitted to the control device 200.

  Converter 20 includes a reactor L1, power semiconductor switching elements Q1, Q2, and antiparallel diodes D1, D2. As a power semiconductor switching element (hereinafter simply referred to as “semiconductor switching element”), an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor), or the like can be applied.

  Semiconductor switching element Q1 is electrically connected between main negative bus MNL and node Nd, and semiconductor switching element Q2 is electrically connected between main positive bus MPL and node Nd. Hereinafter, the semiconductor switching element Q1 is also referred to as a lower arm element, and the semiconductor switching element Q2 is also referred to as an upper arm element. The semiconductor switching elements Q1, Q2 are controlled to be turned on / off by switching control signals S1, S2 from the control device 200.

  Reactor L1 is connected between the positive electrode of power storage device 10 and node Nd. That is, reactor L1 is electrically connected between main positive bus MPL and power storage device 10 via semiconductor switching element Q2.

  Voltage sensor 105 detects an input side (secondary battery side) voltage of converter 20, that is, output voltage Vb of secondary battery 10. Note that the voltage Vb may be usually measured by a voltage sensor (not shown) provided corresponding to the secondary battery 10. The detected voltage Vb is transmitted to the control device 200.

  Smoothing capacitor C1 is connected between main positive bus MPL and main negative bus MNL. Voltage sensor 110 detects a DC voltage Vh between main positive bus MPL and main negative bus MNL. The detected voltage Vb is sent to the control device 200.

  Inverters 30-1 and 30-2 are connected in parallel to main positive bus MPL and main negative bus MNL. Inverter 30-1 is a normal three-phase inverter composed of semiconductor switching elements Q11 to Q16 and antiparallel diodes D11 to D16. The semiconductor switching elements Q11 to Q16 are controlled to be turned on / off by switching control signals S11 to S16 from the control device 200. Similarly, inverter 30-2 is a normal three-phase inverter composed of semiconductor switching elements Q21 to Q26 and antiparallel diodes D21 to D26. The semiconductor switching elements Q21 to Q26 are controlled to be turned on / off by switching control signals S21 to S26 from the control device 200.

  U, V and W phases of inverter 30-1 are connected to U phase coil winding U1, V phase coil winding V1 and W phase coil winding W1 of motor generator MG1, respectively. Similarly, U, V and W phases of inverter 30-2 are connected to U phase coil winding U2, V phase coil winding V2 and W phase coil winding W2 of motor generator MG2, respectively.

  Motor generators MG1 and MG2 are connected in common to an engine (not shown) and a power split mechanism (not shown), and motor generator MG2 is a driving force of wheels (not shown), that is, driving of electric vehicle 100. It is configured to generate force. Motor generator MG2 performs regenerative power generation during regenerative braking of electrically powered vehicle 100. Note that regenerative braking here refers to braking that involves regenerative power generation when the driver operating the hybrid vehicle performs a footbrake operation, or regenerative braking by turning off the accelerator pedal while the vehicle is running, although the footbrake is not operated. This includes decelerating (or stopping acceleration) the vehicle while generating electricity.

  Motor generator MG1 is driven to rotate by the rotational force of the engine and operates as a generator, and can operate as a motor as a starter of the engine when the engine is started. At this time, inverter 30-1 performs bidirectional power conversion between AC power that is driving power or generated power of motor generator MG1 and DC power on main positive bus MPL. Similarly, inverter 30-2 performs bidirectional power conversion between AC power that is drive power or generated power of motor generator MG2 and DC power on main positive bus MPL.

  It is noted that a power split mechanism (not shown) is constituted by a planetary gear mechanism connected to the engine output shaft and the output shafts of motor generators MG1 and MG2, so that the rotational speeds of motor generators MG1 and MG2 and the engine rotational speeds can be reduced. Since the continuously variable transmission mechanism that variably controls the ratio can be configured, the operating point of the engine can be set appropriately.

  Current sensor 121 and rotation angle sensor 125 are arranged corresponding to motor generator MG1. Current sensor 121 is provided to detect motor current MRC1, which is a current of each phase of motor generator MG1. The rotation angle sensor 125 detects the rotor rotation angle θ1 of the motor generator MG1. The detected motor current MRC1 and rotor rotation angle θ1 are transmitted to control device 200. Control device 200 can calculate the rotational speed (rotational angular velocity) of motor generators MG1 and MG2 based on rotor rotational angles θ1 and θ2.

  Similarly, current sensor 122 and rotation angle sensor 126 are arranged corresponding to motor generator MG2. Current sensor 122 is provided to detect motor current MRC2 that is a phase current of motor generator MG2. Rotation angle sensor 126 detects rotor rotation angle θ2 of motor generator MG2. The detected motor current MRC2 and rotor rotation angle θ2 are transmitted to control device 200. Since the sum of instantaneous values of the phase currents is zero, it is sufficient to arrange the current sensors 121 and 122 to detect currents for two phases as shown in FIG.

  The control device 200 is typically composed of an electronic control unit (ECU) that incorporates a microcomputer (not shown) and a memory (not shown), and in accordance with a predetermined program process, an upper electronic control unit (ECU) Switching control signals S1, S2 (converter 20), S11 for switching control of converter 20 and inverters 30-1, 30-2 so that motor generators MG1, MG2 operate according to the command values input from S16 (inverter 30-1) and S21 to S26 (inverter 30-2) are generated.

  The command value input to control device 200 is a motor generator MG1, which is set based on a signal from a sensor (not shown) for detecting the traveling state of electric vehicle 100, or on the accelerator opening and the brake depression amount. It includes torque target values TR1 and TR2 of MG2 and target voltage Vhr of voltage Vh. Based on detected motor currents MRC1, MRC2 and rotor rotation angles θ1, θ2, control device 200 controls inverters 30-1, 30- so that output torque of motor generators MG1, MG2 becomes torque target values TR1, TR2. In order to control the supply current (or supply voltage) from 2 to motor generators MG1 and MG2, switching control signals S11 to S16 and S21 to S26 are generated. Generally, during power running operation in which motor generators MG1 and MG2 generate travel driving force, torque target values TR1 and TR2 are set to positive values, and during regenerative braking, torque target values TR1 and TR2 are set to negative values. Is done.

  Control device 200 generates switching control signals S1 and S2 of converter 20 based on detected voltages Vb and Vh so that voltage Vh becomes target voltage Vhr. Then, control device 200 controls the on-period ratio (duty ratio) of semiconductor switching elements Q1 and / or Q2 within a certain switching cycle (the sum of on-period and off-period).

  Converter 20 performs bidirectional DC voltage conversion between secondary battery 10 and main positive bus MPL and main negative bus MNL based on switching control signals S 1 and S 2 from control device 200. Converter 20 basically boosts the DC power received from secondary battery 10 when secondary battery 10 is discharged (Ib> 0), and when secondary battery 10 is charged (Ib <0). The DC power (regenerative power) received from the main positive bus MPL and the main negative bus MNL is stepped down.

  During the boosting operation, control device 200 maintains upper arm element Q2 in the off state and turns on and off lower arm element Q1 to control the duty ratio. Thereby, in the ON period of lower arm element Q1, a pump current flows from secondary battery 10 through reactor L1, lower arm element Q1, and main negative bus MNL in this order. Reactor L1 accumulates electromagnetic energy by this pump current. When lower arm element Q1 transitions from the on state to the off state, reactor L1 superimposes the accumulated electromagnetic energy on the discharge current. As a result, the average voltage of the DC power supplied from converter 20 to main positive bus MPL and main negative bus MNL corresponds to the electromagnetic energy of reactor L1 and the energy supplied from secondary battery 10 according to the duty ratio. The voltage is boosted. During the boosting operation, the converter 20 may be controlled so that the upper arm element Q2 is turned on and the upper arm element and the lower arm element are turned on and off in a complementary manner during the off period of the lower arm element Q1. Is possible.

  On the other hand, during the step-down operation, as a basic operation, control device 200 maintains lower arm element Q1 in the off state and turns on and off upper arm element Q2 to control the duty ratio. Thereby, in the ON period of upper arm element Q2, the charging current flows to secondary battery 10 via main arm bus MPL and upper arm element Q2 and reactor L1 in this order. When upper arm element Q2 transitions from the on state to the off state, magnetic flux is generated so that reactor L1 prevents the current from changing, so that the charging current continues to flow through diode D1 and reactor L1. On the other hand, in terms of electrical energy, since the DC power is supplied from the main positive bus MPL and the main negative bus MNL only during the ON period of the upper arm element Q2, the charging current is assumed to be kept constant. (Assuming that the inductance of reactor L1 is sufficiently large), the average voltage of the DC power supplied from converter 20 to secondary battery 10 is stepped down according to the duty ratio of the DC voltage between main positive bus MPL and main negative bus MNL. Value. Even during the step-down operation, converter 20 is controlled so that lower arm element Q1 is turned on and upper arm element and lower arm element are turned on and off in a complementary manner during the off period of upper arm element Q2. Is also possible.

  As is well known, in the converter 20 composed of a step-up / step-down chopper, the boosting operation is emphasized as the ON period ratio of the lower arm element Q1 during the boosting operation becomes higher, and between the main positive bus MPL and the main negative bus MNL. The DC voltage Vh increases. Further, during the step-down operation, voltage conversion with a higher voltage ratio Vh / Vb is performed as the ON period ratio of the upper arm element Q2 becomes lower (in other words, the OFF period ratio becomes higher).

  Furthermore, electric vehicle 100 according to the embodiment of the present invention is configured such that secondary battery (power storage device) 10 can be charged by AC power supplied from external power supply 90 or 90 # as described below. .

  Electric vehicle 100 further includes a connector 50 for connecting neutral point NP1 of motor generator MG1 and neutral point NP2 of motor generator MG2 to external power supply 90, a relay switch 51, and a capacitor C2. In other words, electric vehicle 100 can supply AC power from external power supply 90 (typically commercial power supply) connected to connector 50 by connector 92 between neutral points NP1 and NP2 via relay switch 51. It is configured. Capacitor C <b> 2 is arranged to remove a high frequency component of the AC voltage supplied from external power supply 90.

  Therefore, external power supply 90 can be electrically connected to neutral points NP1 and NP2 by connecting connector 50 and connector 92 and turning on relay switch 51 while electric vehicle 100 is stopped. In this case, AC components from the external power supply 90 are generated by the reactor components of motor generators MG1 and MG2 (inductances of coil windings U1, V1, W1, U2, V2, and W2) and inverters 30-1 and 30-2. A “charging power conversion device” according to the present invention that converts a voltage into a DC voltage is configured. The converted DC voltage is output between the main positive bus MPL and the main negative bus MNL and used for charging the secondary battery 10.

  Alternatively, instead of the neutral point charging method as described above, an external charging power converter 95 that converts an AC voltage from the external power supply 90 # into a DC voltage without using the inverters 30-1 and 30-2 is provided. It is good also as a structure provided separately. In that case, AC voltage from external power supply 90 # connected to electrically powered vehicle 100 is removed by high-frequency component by capacitor C2 # by connection of connector 50 # and connector 92 #, and then by power converter 95. Converted to DC voltage. The DC voltage output from power converter 95 between main positive bus MPL and main negative bus MNL is used for charging secondary battery 10 (power storage device). In this case, the power converter 95 corresponds to the “charging power conversion device” in the present invention.

  Thus, electrically powered vehicle 100 according to the present embodiment uses secondary power supplied from external power sources 90 and 90 # in addition to charging secondary battery (power storage device) 10 by regenerative braking power generation while the vehicle is running. The battery 10 can be charged. Hereinafter, such an operation mode in which the secondary battery (power storage device) 10 is charged by the external power sources 90 and 90 # will be referred to as an “external charging mode”. Generally, the external charging mode is executed for a relatively long time (for example, at night) when the vehicle is parked.

  Here, in the configuration of the electric vehicle shown in FIG. 1, the secondary battery (power storage device) 10, the converter 20, the inverters 30-1 and 30-2, and the sensor groups 105, 106, 110, and the like arranged on these. In addition, the control device 200 constitutes a “power supply system” according to the present invention. In particular, main positive bus MPL corresponds to “power line” in the present invention, voltage sensor 110 corresponds to “voltage detector” in the present invention, and current sensor 106 corresponds to “current detector” in the present invention. . Semiconductor switching elements Q1 and Q2 constituting converter 20 correspond to “a plurality of power semiconductor switching elements” in the present invention. The inverters 30-1 and 30-2 correspond to the “first inverter” and the “second inverter” in the present invention. Further, motor generators MG1 and MG2 correspond to “first AC rotating electric machine” and “second AC rotating electric machine” in the present invention. The external charging mode corresponds to the “charging mode” in the present invention. The control device 200 corresponds to the “control device” and the “inverter control device” in the present invention.

  Next, charging control in the external charging mode in the power supply system mounted on the electric vehicle according to the embodiment of the present invention will be described.

FIG. 2 is a schematic waveform diagram of the charging current of the secondary battery 10 in the external charging mode.
As shown in FIG. 2, in the external charging mode, charging current | Ib | includes a frequency related to the power supply frequency of external power supplies 90 and 90 #, for example, when external power supplies 90 and 90 # are single-phase AC power supplies. Is superimposed with an AC component having a frequency twice the power supply frequency. That is, the AC component corresponds to the current fluctuation of the charging current Ib. For example, the fluctuation range of the charging current | Ib | is | I1-I2 |.

  If the fluctuation range is large, the voltage between the terminals of the secondary battery 10 fluctuates with the fluctuation of the charging current. Therefore, the voltage between the terminals of the secondary battery 10 is reduced in external charging in a cryogenic environment where the internal resistance is large. Reaching the upper limit may make it impossible to continue charging. On the other hand, if the average value (effective value) of the charging current | Ib | is reduced in order to avoid such a phenomenon, the amount of charge per unit time is reduced, so that the charging time becomes longer. Further, since the alternating current of the ripple component always flows through the reactor L1 connected to the charging path, charging efficiency is reduced due to generation of reactive power.

  Therefore, as will be described below, in the power supply system according to the present embodiment, current fluctuation (AC component) of the charging current caused by the power supply frequency of such an external power supply is controlled by DC voltage Vh by converter 20. Suppress by.

  FIG. 3 is a schematic block diagram illustrating the configuration of converter control unit 205 in the power supply system according to the embodiment of the present invention.

  The converter control unit 205 shown in FIG. 3 is a part of the function achieved by the control device 200 shown in FIG. 1, and each block shown in FIG. 3 is processed by hardware or software by the control device 200. Is realized.

  Referring to FIG. 3, converter control unit 205 includes a voltage control unit 210a, a current smoothing control unit 210b, an addition unit 260, and a modulation unit 270.

  Converter control unit 205 calculates voltage conversion ratio β by converter 20, and modulation unit 270 performs switching so that semiconductor switching elements Q 1 and / or Q 2 are on / off controlled at a duty ratio according to the calculated voltage conversion ratio β. It is configured to generate control signals S1, S2. The voltage control unit 210 a includes a feedforward control unit 215, a feedback control unit 220, and a subtraction unit 225.

  Here, the voltage conversion ratio β is represented by the inverse ratio of the input / output voltage of the converter 20, that is, Vb / Vh. Therefore, if the duty ratio (on period ratio) α is defined by the following equation (1) by at least the on period Ton and the off period Toff of the semiconductor switching element Q1 that is turned on / off at the time of the boost operation, the voltage conversion ratio β is (2) It is shown by the formula. That is, the voltage conversion ratio β corresponds to at least the duty ratio (on period ratio) of the semiconductor switching element Q2 that is turned on / off during the step-down operation.

α = Ton / (Ton + Toff) (1)
β = Vb / Vh = 1−α (2)
The feedforward control unit 215 calculates β (FF) as the reciprocal of the theoretical boost ratio based on the target voltage Vhr of the voltage Vh and the voltage Vb, that is, the input voltage of the converter 20, according to the following equation (3).

β (FF) = Vb / Vhr (3)
Feedback control unit 220 includes a subtraction unit 222, a PI control unit 224, and a calculation unit 226.

  The subtractor 222 calculates a voltage deviation ΔVh (ΔVh = Vhr−Vh) between the voltage Vh detected by the voltage sensor 110 and the target voltage Vhr. The PI control unit 224 performs a proportional integration calculation on the voltage deviation ΔVh obtained by the subtraction unit 222 and outputs the calculation result. The calculation unit 226 calculates β (FB) indicating a voltage conversion ratio to be corrected based on the feedback of the voltage Vh by dividing the voltage deviation proportionally integrated by the PI control unit 224 by the target voltage Vhr. To do.

  The subtraction unit 225 uses the voltage conversion ratio β for controlling the voltage Vh to the target voltage Vhr based on β (FF) obtained by the feedforward control unit 215 and β (FE) obtained by the feedback control unit 220. The basic amount β0 is calculated. As a result, when the target voltage Vhr> the voltage Vh with respect to the theoretical voltage conversion ratio based on the target voltage Vhr set by the feedforward control, the voltage conversion ratio β (β0) is reduced, that is, the voltage Vh. Feedback control acts in the direction of increasing the.

  The current smoothing control unit 210b that operates in the external charging mode includes a reactor voltage estimation unit 240, a bandpass filter 245, and a correction amount calculation unit 250.

  Reactor voltage estimation unit 240 includes a multiplication unit 242 and a subtraction unit 244. Multiplier 242 calculates estimated voltage Vd # at node Nd by multiplying voltage conversion ratio β by converter 20 and the detected value of voltage Vh by voltage sensor 110. Then, subtraction unit 244 calculates estimated voltage Vl # of voltage Vl of reactor L1 based on the detected value of voltage Vb by voltage sensor 105 and estimated voltage Vd # obtained by multiplication unit 242 (Vl # = Vb-Vd #). Since Ib <0 during external charging, Vl # <0 also holds for Vl #.

  Bandpass filter 245 extracts an AC component corresponding to the power supply frequency of external power supplies 90 and 90 # from estimated voltage Vl # estimated by reactor voltage estimating unit 240. For example, when the power supply frequency of external power supplies 90 and 90 # is 60 (Hz), bandpass filter 245 is designed to extract a frequency component near 120 (Hz) in estimated voltage Vl #. . The extracted AC voltage component is output as a voltage fluctuation Vlac.

  The correction amount calculation unit 250 receives the voltage fluctuation Vlac extracted by the bandpass filter 245 as an input, a PI control unit 252 that performs proportional control calculation, and a calculation for dividing the control calculation result by the PI control unit 252 by the target voltage Vhr. Part 254. The calculation result by the calculation unit 254 is output as the correction amount βc.

  In this way, the current smoothing control unit 210b can set the correction amount βc of the voltage conversion ratio β necessary for changing the voltage Vh so as to suppress the voltage fluctuation Vlac. The correction amount βc is basically a value that changes at the same frequency as the frequency component extracted by the bandpass filter 245. When the charging current | Ib | increases (Ib decreases), the estimated voltage Vl # (Vl # <0) also changes in a decreasing direction. Therefore, the correction amount βc decreases the voltage conversion ratio β. That is, the current smoothing control unit 210b acts so as to change the voltage Vh in the increasing direction. Note that the correction amount βc = 0 is fixed during normal operation other than the external charging mode.

  The adding unit 260 determines the voltage at the converter 20 according to the sum of the basic amount β0 of the voltage conversion ratio β obtained by the voltage control unit 210a and the correction amount βc of the voltage conversion ratio β obtained by the current smoothing control unit 210b. A conversion ratio β is calculated. That is, β = β0 is set in the normal operation other than the external charging mode, while β = β0 + βc is set in the external charging mode.

  Modulation unit 270 receives voltage conversion ratio β and generates switching control signals S1 and S2 such that the duty ratio of semiconductor switching elements Q1 and Q2 conforms to voltage conversion ratio β. As understood from the equation (2), during the step-up operation, the ON period ratio of the lower arm element Q1 decreases as the voltage conversion ratio β increases. On the other hand, during the step-down operation including the external charging mode, the on-period ratio of the upper arm element Q2 increases as the voltage conversion ratio β increases.

  As a result, when the charging current | Ib | increases (Ib decreases), the correction amount βc changes in a direction to decrease the voltage conversion ratio β so that the ON period ratio of the upper arm element Q2 decreases. The Vh control by the converter 20 is corrected. On the other hand, when the charging current | Ib | is decreased (Ib is increased), the correction amount βc is changed in the direction of increasing the voltage conversion ratio β, so that the ON period ratio of the upper arm element Q2 is increased. The Vh control by the converter 20 is corrected. That is, the current smoothing control unit 210b corrects the Vh control by the converter 20 in the direction that prevents the change in the current Ib (charging current), that is, the direction that cancels the AC component (current fluctuation), based on the voltage fluctuation Vlac. It will be.

  In the configuration of FIG. 3, the reactor voltage estimation unit 240 corresponds to the “voltage estimation unit” of the present invention, and the bandpass filter 245 corresponds to the “frequency filter unit” of the present invention, and the correction amount calculation unit 250. Corresponds to the “control operation unit” of the present invention.

  FIG. 4 is a flowchart for executing converter control according to the embodiment of the present invention shown in FIG. 3 by a program stored in control device 200 in advance.

  Referring to FIG. 4, in step S110, control device 200 determines based on detected values of voltage Vb and voltage Vh corresponding to the input voltage and output voltage of converter 20, respectively, and target voltage Vhr of voltage Vh, as shown in FIG. The basic amount β0 of the voltage conversion ratio β is calculated by the same calculation as the voltage control unit 210a shown in FIG.

  And control device 200 judges whether it is an external charge mode by Step S110. If the external charging mode is selected (YES in S110), control device 200 indirectly transmits the AC component (current fluctuation) of the charging current without using the detection value of the current sensor in step S120. To detect. Step S120 includes sub-steps S122, S124, and S126.

  In sub-step S122, control device 200 obtains estimated value Vl # of reactor voltage Vl by the same calculation as that performed by reactor voltage estimating unit 240 shown in FIG. In sub-step S124, voltage variation Vlac is extracted from estimated voltage Vl # by the same processing as that of bandpass filter 245 in FIG. Further, in sub-step S126, control device 200 performs voltage conversion ratio β necessary for changing voltage Vh so as to suppress voltage fluctuation Vlac by the same calculation as correction amount calculation unit 250 shown in FIG. The correction amount βc is calculated.

  In step S130, control device 200 calculates voltage conversion ratio β of converter 20 according to the following equation (4).

β = β0 + βc (4)
On the other hand, when the mode is other than the external charging mode (when NO is determined in S110), that is, during normal operation, control device 200 directly sets basic amount β0 obtained in step S110 as voltage conversion ratio β in step S140 (β = β0).

  Further, in step S150, control device 200 determines switching control signals S1 and S2 such that semiconductor switching elements Q1 and / or Q2 are turned on / off according to voltage conversion ratio β obtained in step S130 or S140.

  Through the above series of processing, converter control similar to the block diagram shown in FIG. 3 can be executed.

  In the flowchart of FIG. 4, step S100 corresponds to “a step of calculating the basic amount of the voltage conversion ratio” in the present invention, and step S120 corresponds to “a step of calculating the correction amount of the voltage conversion ratio”. Step S150 corresponds to “a step of generating a signal”. In particular, the sub-step S122 corresponds to the “sub-step for estimating the voltage of the reactor” in the present invention, and the sub-step S124 corresponds to the “sub-step for extracting voltage fluctuation” in the present invention, and the sub-step S126. Corresponds to “a sub-step for performing a control calculation for obtaining a correction amount” in the present invention.

  As described above, according to the power supply system of the present embodiment, in the external charging mode, the voltage fluctuation Vlac caused by the AC component of the charging current is obtained based on the estimation of the reactor voltage, and the voltage fluctuation Vlac is canceled. The voltage conversion ratio β in the converter 20 can be corrected. Therefore, the Vh control by the converter 20 can be performed so as to suppress the current fluctuation of the charging current, so that the charging trouble caused by the fluctuation of the charging current can be eliminated, the charging time can be shortened, or the converter efficiency at the time of charging can be improved. It becomes possible to plan.

  Further, since the converter control can be realized only by detecting the input / output voltage of the converter 20 without using the current detection value of the secondary battery 10 directly, the secondary battery 10 (power storage device) and the converter 20 are arranged separately. Also in the vehicle layout, fluctuations in the charging current (alternating current component) are suppressed in the external charging mode without eliminating problems such as a delay in transmission of the detected charging current value or without newly arranging a current sensor in the converter 20. Converter control can be realized.

(Modification)
Next, a modification of the power supply system according to the embodiment of the present invention will be described. In this modification, the configurations of the power supply system and the electric vehicle are basically the same as those shown in FIG. 1, and thus detailed description will not be repeated.

  FIG. 5 is a block diagram illustrating converter control in a power supply system according to a modification of the embodiment of the present invention.

  Referring to FIG. 5, converter control unit 205 # according to the modification of the embodiment omits arrangement of reactor voltage estimation unit 240 in current smoothing control unit 210b as compared with converter control unit 205 shown in FIG. Is different. Further, the current Ib detected by the current sensor 106 is input to the band pass filter 245.

  In the modification of the embodiment of the present invention, the current sensor 106 controls the transmission time from the current sensor 106 to the control device 200 according to the vehicle layout in which the secondary battery 10 (power storage device) and the converter 20 are arranged close to each other. It is assumed that it is placed in a place that does not affect Alternatively, the current sensor 106 is assumed to be disposed in advance in the converter 20 so that the charge / discharge current (current Ib) of the secondary battery 10 can be detected.

  The band pass filter 245 outputs an alternating current component of the charging current Ib, that is, a current fluctuation Ibac, based on the detection value of the current sensor 106. The current fluctuation Ibac is an alternating current having a frequency similar to that of the voltage fluctuation Vlac shown in FIG.

  Correction amount calculation unit 250 includes a PI control unit 252 # and a calculation unit 254. PI control unit 252 # receives current fluctuation Ibac extracted by bandpass filter 245 as input and performs proportional control calculation. Arithmetic unit 254 obtains correction amount βc of voltage conversion ratio β by dividing the control calculation result by PI control unit 252 # by target voltage Vhr.

  In this manner, the current smoothing control unit 210b can set the correction amount βc of the voltage conversion ratio β necessary for changing the voltage Vh so as to suppress the current fluctuation Ibac. That is, as in the case of FIG. 2, when the charging current | Ib | increases (Ib decreases), the current fluctuation Ibac changes in a decreasing direction, so that the correction amount βc decreases the voltage conversion ratio β. That is, the current smoothing control unit 210b operates so as to change in the direction of increasing the voltage Vh. Note that the correction amount βc = 0 is fixed during normal operation other than the external charging mode.

  Since the configuration and operation of other parts of converter control unit 205 # are similar to those of converter control unit 205, detailed description will not be repeated.

  If it does in this way, it will become possible to perform converter control which suppresses the current fluctuation (alternating current component) more correctly using the detection value of charging current Ib of secondary battery 10 as it is. Although current fluctuation Ibac and voltage fluctuation Vlac are different in phase, the switching frequency of converter 20 is relatively higher than the frequency of the fluctuation component related to the power supply frequency of the external power supply. Therefore, PI control units 252 and 252 # By appropriately adjusting the gain, it is possible to suppress the fluctuation (alternating current component) of the charging current of the secondary battery 10 by either converter control of FIG. 2 or FIG.

  FIG. 6 is a flowchart for executing the converter control shown in FIG.

  Referring to FIG. 6, the converter control according to the modification of the embodiment is different from the flowchart shown in FIG. 4 in that step S120 includes sub-steps S122 #, S124 # and S126 #. . Processes other than step S120 are the same as those in FIG. 4, and thus detailed description will not be repeated.

  In sub step S122 #, control device 200 acquires current Ib based on the detection value of current sensor 106. In sub-step S124 #, current fluctuation Ibac, which is an AC component of a frequency related to the power supply frequency in current Ib, is extracted by the same processing as that of band-pass filter 245 (FIG. 5). Further, in sub-step S126 #, control device 200 performs a voltage conversion ratio necessary for changing voltage Vh so as to suppress current fluctuation Ibac by the same calculation as correction amount calculation unit 250 shown in FIG. A β correction amount βc is calculated.

  Converter control similar to the block diagram shown in FIG. 5 can be executed by a series of processes according to the flowchart shown in FIG. In the flowchart of FIG. 6, sub-step S124 # corresponds to “sub-step for extracting current fluctuation” in the present invention, and sub-step S126 # corresponds to “sub-step for performing control calculation for obtaining correction amount” in the present invention. ".

  In the above-described embodiment and its modifications, electric vehicle 100 is not only a hybrid vehicle equipped with an internal combustion engine that generates kinetic energy using fuel, but also an electric vehicle not equipped with an internal combustion engine, and electricity using fuel. It may be a fuel cell vehicle further equipped with a fuel cell that generates energy.

  Further, the control device 200 reads a program including each step of the flowcharts shown in FIGS. 4 and 6 from a memory (not shown) (for example, ROM: Read Only Memory), executes the read program, and performs processing according to the flowchart. It can be configured to execute. Therefore, the memory corresponds to a computer (CPU) readable recording medium in which a program including the steps of the flowcharts described in the present embodiment and its modifications is recorded.

  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 a circuit diagram showing an overall configuration of an electric vehicle equipped with a power supply system according to an embodiment of the present invention. It is a schematic waveform diagram of the charging current of the secondary battery (power storage device) in the external charging mode. It is a block diagram explaining converter control in a power supply system by an embodiment of the invention. It is a flowchart for performing the converter control shown in FIG. 3 by the program previously stored in the control apparatus. It is a block diagram explaining the converter control in the power supply system by the modification of embodiment of this invention. 6 is a flowchart for executing the converter control shown in FIG. 5 by a program stored in advance in a control device.

Explanation of symbols

10 Secondary battery (power storage device), 20 converter, 30-1, 30-2 inverter, 50, 50 #, 92, 92 # connector, 51 relay switch, 90, 90 # external power supply, 95 power converter (external charging) ), 100 electric vehicle, 105 voltage sensor (Vb)
106 current sensor, 110 voltage sensor (Vh), 121, 122 current sensor (MG), 125, 126 rotation angle sensor, 200 controller (ECU), 205 converter control unit, 210a voltage control unit, 210b current smoothing control unit, 215 feedforward control unit, 220 feedback control unit, 222, 225, 244 subtraction unit, 224, 252, 252 # PI control unit, 226, 254 arithmetic unit (division), 240 reactor voltage estimation unit, 242 multiplication unit, 245 band Pass filter, 250 correction amount calculation unit, 260 addition unit, 270 modulation unit, C1 smoothing capacitor, C2 capacitor, D1, D2, D11 to D16, D21 to D26 antiparallel diode, Ib current (charging current), Ibac current fluctuation ( Charging current), MG1, MG2 motor generator , MNL main negative bus (power line), MPL main positive bus (power line), MRC1, MRC2 motor current, Nd node, NP1, NP2 neutral point, Q1 power semiconductor switching element (converter lower arm element), Q2 for power Semiconductor switching elements (converter upper arm elements), Q11 to Q16, Q21 to Q26 Power semiconductor switching elements (inverters), S1, S2 switching control signals (converters), S11 to S16, S21 to S26 switching control signals, TR1, TR2 Torque target value, U1, U2 U phase coil winding, V1, V2 V phase coil winding, Vb voltage (power storage device), Vh voltage (power line), Vhr target voltage Vl reactor voltage, Vl # estimated voltage (reactor voltage) , Vlac voltage fluctuation, W1, W2 W phase coil winding, β voltage換比 rate, the basic [beta] 0 amount (voltage conversion ratios), .beta.c correction amount (voltage conversion ratios), .DELTA.Vh voltage deviation, .theta.1, .theta.2 rotor rotation angle.

Claims (8)

A power supply system mounted on an electric vehicle capable of generating a driving force using electric power on a power line,
A chargeable / dischargeable power storage device;
A converter connected between the power line and the power storage device and configured to include a plurality of power semiconductor switching elements for bidirectionally converting DC voltage between the power storage device and the power line;
A voltage detector for detecting the voltage of the power line;
A control device for controlling on / off of each of the power semiconductor switching elements of the converter so as to maintain the voltage of the power line at a target voltage;
In a charging mode in which the electric vehicle is connected to an external power source, the AC voltage from the external power source is converted into a DC voltage on which a frequency component related to the frequency of the AC voltage is superimposed and output to the power line Charging power conversion device,
The controller is
A voltage control unit for setting a basic amount of a voltage conversion ratio by the converter based on the target voltage, a detection voltage by the voltage detector, and an output voltage of the power storage device;
Current smoothing that sets the correction amount of the voltage conversion ratio so as to change the voltage on the power line so as to cancel the current fluctuation corresponding to the frequency component superimposed on the charging current of the power storage device in the charging mode A control unit;
And a modulation unit that generates a signal for controlling on / off of the plurality of power semiconductor switching elements based on the voltage conversion ratio according to a sum of the basic amount and the correction amount. The converter is
Further including a reactor electrically connected between the power line and the power storage device via one of the plurality of power semiconductor switching elements,
The current smoothing control unit
A voltage estimation unit that estimates a voltage of the reactor based on a detection voltage by the voltage detector, the voltage conversion ratio, and an output voltage of the power storage device;
A frequency filter unit for extracting a voltage fluctuation corresponding to the frequency component from the reactor voltage estimated by the voltage estimation unit;
The power supply system according to claim 1, further comprising: a control calculation unit that obtains a correction amount of the voltage conversion ratio for changing a voltage on the power line so as to cancel the voltage fluctuation extracted by the frequency filter unit. A current detector for detecting an input / output current of the power storage device;
The current smoothing control unit
In the charging mode, a frequency filter unit for extracting the current fluctuation from the charging current detected by the current detector;
The power supply system according to claim 1, further comprising: a control calculation unit that obtains a correction amount of the voltage conversion ratio for changing a voltage on the power line so as to cancel the current fluctuation extracted by the frequency filter unit. The electric vehicle is
A first AC rotating electric machine including a first multiphase winding connected in a star shape as a stator winding;
A second AC rotating electric machine including a second multi-phase winding connected in a star shape as a stator winding;
The power supply system includes:
A first inverter connected to the first multiphase winding and performing power conversion between the first AC rotating electric machine and the power line;
A second inverter connected to the second multiphase winding and performing power conversion between the second AC rotating electric machine and the power line;
In the charging mode, the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding are electrically connected to the external power source. A connector part for,
An inverter control device for controlling on / off of the power semiconductor switching elements of the first and second inverters;
At least one of the first and second AC rotating electric machines is used to generate the traveling driving force,
In the charging mode, the inverter control device is configured such that the first and second inverters and the inductances of the first and second multiphase windings operate as the charging power conversion device, whereby the connector unit The first and second inverters convert the AC voltage from the external power source supplied to the first and second neutral points via the DC to the DC voltage and output it to the power line. The power supply system of any one of Claims 1-3 which controls each of these. A control method for a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line,
The power supply system includes:
A chargeable / dischargeable power storage device;
A converter connected between the power line and the power storage device and configured to include a plurality of power semiconductor switching elements for bidirectionally converting DC voltage between the power storage device and the power line;
A voltage detector for detecting the voltage of the power line;
A control device for controlling on / off of each of the power semiconductor switching elements of the converter so as to maintain the voltage of the power line at a target voltage;
In a charging mode in which the electric vehicle is connected to an external power source, the AC voltage from the external power source is converted into a DC voltage on which a frequency component related to the frequency of the AC voltage is superimposed and output to the power line Charging power conversion device,
The control method is:
Calculating a basic amount of a voltage conversion ratio by the converter based on the target voltage, a detection voltage by the voltage detector, and an output voltage of the power storage device;
Calculating the correction amount of the voltage conversion ratio so as to change the voltage on the power line so as to cancel the current fluctuation corresponding to the frequency component superimposed on the charging current of the power storage device in the charging mode; ,
Generating a signal for controlling on / off of the plurality of power semiconductor switching elements based on the voltage conversion ratio according to the sum of the basic amount and the correction amount. The converter is
Further including a reactor electrically connected between the power line and the power storage device via one of the plurality of power semiconductor switching elements,
The step of calculating the correction amount includes:
A sub-step of estimating a voltage of the reactor based on a detection voltage by the voltage detector, the voltage conversion ratio, and an output voltage of the power storage device;
A sub-step of extracting a voltage fluctuation corresponding to the frequency component from the estimated reactor voltage;
6. The charging control of the power supply system according to claim 5, further comprising a sub-step of performing a control calculation for obtaining a correction amount of the voltage conversion ratio for changing the voltage on the power line so as to cancel the extracted voltage fluctuation. Method. The power supply system includes:
A current detector for detecting an input / output current of the power storage device;
The step of calculating the correction amount includes:
Sub-step of extracting the current fluctuation from the charging current detected by the current detector in the charging mode;
6. The charging of the power supply system according to claim 5, further comprising a sub-step of performing a control operation for obtaining a correction amount of the voltage conversion ratio for changing a voltage on the power line so as to cancel the extracted current fluctuation. Control method. The electric vehicle is
A first AC rotating electric machine including a first multiphase winding connected in a star shape as a stator winding;
A second AC rotating electric machine including a second multiphase winding connected in a star shape as a stator winding;
The power supply system includes:
A first inverter connected to the first multiphase winding and performing power conversion between the first AC rotating electric machine and the power line;
A second inverter connected to the second multiphase winding and performing power conversion between the second AC rotating electric machine and the power line;
In the charging mode, the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding are electrically connected to the external power source. A connector part for,
An inverter control device for controlling on / off of the power semiconductor switching elements of the first and second inverters;
At least one of the first and second AC rotating electric machines is used to generate the traveling driving force,
In the charging mode, the inverter control device is configured such that the first and second inverters and the inductances of the first and second multiphase windings operate as the charging power conversion device, whereby the connector unit The first and second inverters convert the AC voltage from the external power source supplied to the first and second neutral points via the DC to the DC voltage and output it to the power line. The charge control method for the power supply system according to any one of claims 5 to 7, wherein each of the power supply systems is controlled.

Images