JP2009071898A - Charging control system for power storage mechanism and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the generation of an excessive current at the start of charging without reducing efficiency in charging, even if an error occurs in a voltage sensor for measuring an output voltage of an external power supply in a vehicle equipped with a power storage mechanism capable of being charged with the external power supply. <P>SOLUTION: A voltage VH of a power line outputting an external power supply voltage which is converted is stepped up to an upper limit voltage VHmax in a time period T1 while the external power supply is interrupted. While the external power supply is connected at a time t1, since the voltage VH has been stepped up, an excessive rush current flowing from the external power supply is prevented. In a time period T2, the direction of a current Iac is monitored while gradually reducing the voltage VH, thereby obtaining a voltage VH* of the power line equilibrium to the converted voltage of the external power supply. In a time period T4, the battery (power storage mechanism) is charged using the power from the external power supply in conformity with a charging command in a state where the voltage VH is lowered at not more than VH*. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a charge control system for a power storage mechanism and a control method therefor, and more specifically to a technique for charging a power storage mechanism mounted on a vehicle with power supplied from a power source outside the vehicle.

  Conventionally, vehicles using an electric motor as a drive source, such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle, are known. Such a vehicle is equipped with a power storage mechanism such as a battery in order to store power supplied to the electric motor. The battery stores power generated during regenerative braking and power generated by a generator mounted on the vehicle.

  In recent years, a configuration has been proposed in which the power storage mechanism is charged with a power source outside the vehicle (hereinafter also simply referred to as an external power source) such as a power source for a house. Specifically, the power storage mechanism (battery) of the vehicle is charged by the power supplied from the power source of the house by connecting the outlet provided in the house and the connector provided in the vehicle with a cable. Hereinafter, a vehicle capable of charging a power storage mechanism such as a battery mounted on the vehicle by an external power source of the vehicle is also referred to as a “plug-in vehicle”.

  The standard for plug-in vehicles is established in Japan by “General Requirements for Conductive Charging Systems for Electric Vehicles” (Non-Patent Document 1), and in the United States by “SA Electric Vehicle Conductive Charge Coupler” (Non-Patent Document 2). Is done.

As one form of such a charging system in a plug-in vehicle, as disclosed in Japanese Patent Laid-Open No. 11-205909 (Patent Document 1), a voltage sensor is arranged so as to measure an AC voltage from an external AC power source. A configuration is proposed. Furthermore, in the configuration of Patent Document 1, an earth leakage circuit breaker having a hall sensor, a detection circuit, an earth leakage relay, an earth leakage test relay, and an earth leakage resistance is detected between the outlet of the external AC power supply and the electric vehicle. Provide. Then, at the time of charging, the leakage test relay is forcibly short-circuited in a closed state, and charging is started after confirming whether the leakage relay is cut off.
JP-A-11-205909 “General Requirements for Conductive Charging Systems for Electric Vehicles”, Japan Electric Vehicle Association Standard (Japan Electric Vehicle Standard), March 29, 2001 “SAE Electric Vehicle Conductive Charge Coupler” (USA), SAE Standards, SAE International, November 2001

  If the configuration is such that the output voltage of the external power supply can be detected by a voltage sensor as in Patent Document 1, no overcurrent occurs when the power storage mechanism is charged by the external power supply (hereinafter also referred to as “external charging”). As described above, appropriate charge control can be performed.

  However, in such charge control, there is a possibility that a malfunction may occur in charging when an error occurs in the voltage sensor. In particular, when charging starts, an unintended voltage difference may cause an excessive current such as an inrush current.

  Alternatively, it is possible to prevent the occurrence of a large inrush current from the external power supply if the charging operation is performed while maintaining the state where the power storage mechanism cannot be charged unless the supply voltage from the external power supply is significantly increased. . On the other hand, if the control configuration requires a large step-up operation at all times during external charging, there is a possibility that the charging efficiency may be reduced due to the occurrence of switching loss related to voltage conversion.

  The present invention has been made to solve such problems, and an object of the present invention is to accurately detect the output voltage of an external power supply in a vehicle equipped with a power storage mechanism that can be charged by an external power supply. Even if it is not possible, it is to realize charging control that can reliably prevent the occurrence of excessive current without reducing the efficiency during charging.

  A charge control system for a power storage mechanism according to the present invention is a charge control system for a power storage mechanism mounted on an electric vehicle, and includes a converter, a feeder, a current detector, a switching device, a charge power converter, and a control. Device. The converter controls the voltage of the power line, which is configured to be capable of bi-directional power conversion between the power storage mechanism and the power line, to a target voltage. The power supply line is electrically connected to the external power source via the connector in the external charging mode in which the power storage mechanism is charged by the external power source of the electric vehicle. The current detector detects a current flowing through the feeder line. The switchgear is inserted and connected to the power supply line. The charging power converter is provided between the power supply line and the power line, converts an AC voltage from an external power source into a DC voltage, and outputs the DC voltage to the power line. The control device controls the operation of the charging control system in the external charging mode. The control device includes a pre-charging boosting unit, a voltage balance condition determining unit, and a charging control unit. The pre-charging boosting unit sets the target voltage to a predetermined voltage higher than the highest voltage that the charging power conversion device converts the AC voltage and outputs to the power line with the switchgear opened. The voltage balance condition determining unit closes the switchgear after the power line is set to a predetermined voltage by the pre-charging booster, and further monitors the detection current by the current detector while gradually decreasing the target voltage. Then, an equilibrium voltage, which is a target voltage when the output voltage of the charging power converter becomes equal to the voltage on the power line, is determined. The charge control unit sets the target voltage to be equal to or lower than the equilibrium voltage, and charges the power storage mechanism by controlling the operation of the charging power conversion device according to the charge command for the power storage mechanism.

  Or this invention is a control method of the charge control system of the electrical storage mechanism mounted in the electric vehicle, Comprising: A charge control system is a converter, a feeder, a current detector, a switching device, and a charging power converter. With. The converter controls the voltage of the power line, which is configured to be capable of bi-directional power conversion between the power storage mechanism and the power line, to a target voltage. The power supply line is electrically connected to the external power source via the connector in the external charging mode in which the power storage mechanism is charged by the external power source of the electric vehicle. The current detector detects a current flowing through the feeder line. The switchgear is inserted and connected to the power supply line. The charging power converter is provided between the power supply line and the power line, converts an AC voltage from an external power source into a DC voltage, and outputs the DC voltage to the power line. And, in the external charging mode, the control method includes setting the target voltage to a predetermined voltage higher than the highest voltage that the charging power conversion device converts the AC voltage and outputs to the power line in a state in which the switching device is opened, and After the power line is set to a predetermined voltage, the step of closing the switchgear and charging the battery by monitoring the current detected by the current detector while gradually lowering the target voltage while the switchgear is closed A step of determining an equilibrium voltage that is a target voltage when the output voltage of the power conversion device is equivalent to a voltage on the power line; setting the target voltage below the equilibrium voltage; and charging the power conversion device in accordance with a charge command of the power storage mechanism Charging the power storage mechanism by controlling the operation.

  With this configuration, by performing a pre-charge boosting operation in advance, it is possible to reliably prevent an inrush current from an external power source when the switchgear is closed, and to stably perform a charging operation without causing an overcurrent. Can start. Furthermore, the charging operation can be executed in a state in which the voltage of the power line is gradually decreased from the pre-charging step-up operation to a voltage level that does not require excessive boosting of the output voltage of the external power supply. As a result, even if the output voltage of the external power source cannot be accurately detected, it is possible to realize charge control that can reliably prevent the occurrence of an excessive current without reducing the efficiency during charging.

  Preferably, the charging control system further includes a voltage detector that detects a voltage on the power supply line, and the control device corrects the detected voltage based on a voltage ratio between the balanced voltage and a peak value of the detected voltage by the voltage detector. A gain setting unit for calculating the gain is further included. Alternatively, the control method further includes a step of calculating a correction gain of the detection voltage based on a voltage ratio between the balanced voltage and the peak value of the detection voltage by the voltage detector.

  More preferably, the charging control unit controls the operation of the charging power conversion device according to feedback control based on the detection current by the current detector and the detection voltage corrected according to the correction gain. Alternatively, in the charging step, the operation of the charging power converter is controlled according to feedback control based on the detection current by the current detector and the detection voltage corrected according to the correction gain.

  Preferably, the control device further includes an abnormality detection unit. The abnormality detection unit detects an abnormality of the charge control system when the voltage ratio is higher than a first predetermined value greater than 1.0 or when the voltage ratio is lower than a second predetermined value smaller than 1.0. Stop external charging operation. Alternatively, the control method detects an abnormality of the charge control system when the voltage ratio is higher than a first predetermined value greater than 1.0, or when the voltage ratio is lower than a second predetermined value smaller than 1.0. And a step of stopping the external charging operation.

  With this configuration, when the charging power conversion device obtains an equilibrium voltage corresponding to the voltage level on the power supply line, which is balanced with the DC voltage output by converting the AC voltage from the external power supply, the output voltage of the external power supply is calculated. The measurement accuracy of the voltage detector to be measured can be evaluated. In particular, the accuracy of charging control can be improved by performing feedback control in which the detection value of the voltage detector is corrected based on the voltage ratio between the detected voltage of the peak value of the external power supply voltage and the balanced voltage. Alternatively, it is possible to prevent a trouble from occurring by detecting that the error of the voltage detector is excessive based on the voltage ratio and stopping the charging operation.

  Alternatively, preferably, the charge control system further includes a voltage detector that detects a voltage on the power supply line, and the voltage balance condition determination unit determines the amount of voltage decrease per time when the target voltage is gradually decreased as the target voltage. And variably set according to the difference between the peak value of the detected voltage by the voltage detector. Alternatively, in the determining step, the amount of voltage decrease per time when the target voltage is gradually decreased is variably set according to the difference between the target voltage and the peak value of the voltage detected by the voltage detector.

  If comprised in this way, the operation | movement which lowers the voltage of a power line to an equilibrium voltage from the voltage level boosted at the time of boosting operation before charge can be rapidly complete | finished. Thereby, the charging operation can be started promptly.

  Preferably, the charging control system further includes a voltage detector that detects a voltage on the power supply line, and the charging power conversion device includes an inverter configured by a plurality of power semiconductor switching elements. When searching for the balanced voltage by the voltage balancing condition determining unit or searching for the balanced voltage by the determining step, the plurality of power semiconductor switching elements are turned on / off according to a predetermined switching pattern, while the charging operation by charging control is performed. Then, on / off of the plurality of power semiconductor switching elements is controlled in accordance with feedback control based on detection values by the current detector and the voltage detector.

  By adopting such a configuration, it is possible to suppress the current passing through the charging power conversion device during the boosting operation before charging and to prevent the occurrence of current loss.

  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 including a stator winding. A second AC rotating electric machine included as a line; first and second inverters; and an inverter control device for controlling on / off of the power semiconductor switching elements of the first and second inverters. 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. At least one of the first and second AC rotating electric machines is used to generate a driving force for driving the electric vehicle. In the external charging mode, the feeder line is connected to the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding via the connector and the charging cable. It arrange | positions so that between external power supplies may be electrically connected. Further, in the external charging mode, the inverter control device is connected to the first and second inverters and the first and second multiphase windings via the feeder line so as to operate as the charging power converter. 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 capable of converting electric power into charging power of a power storage mechanism,
Even if the output voltage of the external power source cannot be accurately detected by the voltage detector, it is possible to reliably prevent the generation of an excessive current without reducing the efficiency during charging.

  According to the charging control system for a power storage mechanism and the control method thereof according to the present invention, in a vehicle equipped with a power storage mechanism that can be charged by an external power supply, the efficiency at the time of charging can be improved even if the output voltage of the external power supply cannot be accurately detected. It is possible to realize charge control that can reliably prevent the occurrence of an excessive current without being reduced.

  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.

(overall structure)
FIG. 1 is a schematic configuration diagram showing a plug-in hybrid vehicle.

  With reference to FIG. 1, a plug-in hybrid vehicle equipped with a charging system for a power storage mechanism according to the present embodiment will be described. This vehicle includes an engine 100, a first MG (Motor Generator) 110, a second MG 120, a power split mechanism 130, a speed reducer 140, and a battery 150 shown as a representative example of the “power storage mechanism”.

  This vehicle travels by driving force from at least one of engine 100 and second MG 120. FIG. 1 illustrates a plug-in hybrid vehicle, but in addition to a charging system for a power storage mechanism mounted on a plug-in vehicle constituted by an electric vehicle or a fuel cell vehicle that travels only by driving force from a motor. However, the point to which the present invention is applicable will be described in a confirming manner.

  Engine 100, first MG 110, and second MG 120 are connected via power split mechanism 130. The power generated by the engine 100 is divided into two paths by the power split mechanism 130. One is a path for driving the front wheels 160 via the speed reducer 140. The other is a path for driving the first MG 110 to generate power.

  First MG 110 is typically a three-phase AC rotating electric machine. First MG 110 generates power using the power of engine 100 divided by power split mechanism 130. The electric power generated by first MG 110 is selectively used according to the running state of the vehicle and the state of charge (SOC) of battery 150. For example, during normal traveling, the electric power generated by first MG 110 becomes electric power for driving second MG 120 as it is. On the other hand, when the SOC of battery 150 is lower than a predetermined value, the power generated by first MG 110 is converted from AC to DC by an inverter described later. Thereafter, the voltage is adjusted by a converter described later and stored in the battery 150.

  When first MG 110 acts as a generator, first MG 110 generates a negative torque. Here, the negative torque means a torque that becomes a load on engine 100. When first MG 110 is supplied with electric power and acts as a motor, first MG 110 generates a positive torque. Here, the positive torque means a torque that does not become a load on the engine 100, that is, a torque that assists the rotation of the engine 100. The same applies to the second MG 120.

  Second MG 120 is typically a three-phase AC rotating electric machine. Second MG 120 is driven by at least one of the electric power stored in battery 150 and the electric power generated by first MG 110.

  The driving force of second MG 120 is transmitted to front wheel 160 via reduction gear 140. Thereby, second MG 120 assists engine 100 or causes the vehicle to travel by the driving force from second MG 120. The rear wheels may be driven instead of or in addition to the front wheels 160.

  During regenerative braking of the plug-in hybrid vehicle, the second MG 120 is driven by the front wheel 160 via the speed reducer 140, and the second MG 120 operates as a generator. Thus, second MG 120 operates as a regenerative brake that converts braking energy into electric power. The electric power generated by second MG 120 is stored in battery 150.

  Power split device 130 includes a planetary gear including a sun gear, a pinion gear, a carrier, and a ring gear. The pinion gear engages with the sun gear and the ring gear. The carrier supports the pinion gear so that it can rotate. The sun gear is connected to the rotation shaft of first MG 110. The carrier is connected to the crankshaft of engine 100. The ring gear is connected to the rotation shaft of second MG 120 and speed reducer 140.

  Engine 100, first MG 110 and second MG 120 are connected via power split mechanism 130 formed of a planetary gear, so that the rotational speeds of engine 100, first MG 110 and second MG 120 are collinear as shown in FIG. The relationship is connected by a straight line.

  Returning to FIG. 1, the battery 150 is an assembled battery configured by connecting a plurality of battery modules in which a plurality of secondary battery cells are integrated in series. The voltage of the battery 150 is about 200V, for example. Battery 150 is charged with electric power supplied from an external power source of the vehicle in addition to first MG 110 and second MG 120.

  Engine 100, first MG 110, and second MG 120 are controlled by an ECU (Electronic Control Unit) 170. ECU 170 may be divided into a plurality of ECUs.

(Electric system configuration)
Next, the configuration of the electrical system of the plug-in hybrid vehicle including the charging system for the power storage mechanism according to the present embodiment will be described with reference to FIGS. 3 and 4.

  Referring to FIG. 3, the plug-in hybrid vehicle includes a converter 200, a first inverter 210, a second inverter 220, a DC / DC converter 230, an auxiliary battery 240, and an SMR (System Main Relay) 250. A DFR (Dead Front Relay) 260, a connector 270, and an LC filter 280.

  Converter 200 includes a reactor, two power semiconductor switching elements (hereinafter also simply referred to as switching elements) connected in series between power lines 190 and 195, and antiparallel diodes provided corresponding to the switching elements. Including reactors. As the power semiconductor switching element, an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor) transistor, a power bipolar transistor, or the like can be appropriately employed. The reactor has one end connected to the positive electrode side of the battery 150 and the other end connected to a connection point between the two switching elements.

  On / off of each switching element is controlled by the ECU 170 so that a DC voltage (also referred to as a system voltage) VH between the power lines 190 and 195 matches the target voltage VR. That is, converter 200 is configured to be capable of bidirectional power conversion between power lines 190, 195 and battery 150, and controls system voltage VH between power lines 190, 195 to target voltage VR.

  When power discharged from the battery 150 is supplied to the first MG 110 or the second MG 120, the voltage is boosted by the converter 200 and output between the power lines 190 and 195. Conversely, when the battery 150 is charged with the electric power generated by the first MG 110 or the second MG 120, the voltage between the power lines 190 and 195 is stepped down by the converter 200.

  System voltage VH between power lines 190 and 195 connecting converter 200 and first inverter 210 and second inverter 220 is detected by voltage sensor 180. The detection result of voltage sensor 180 is transmitted to ECU 170.

  First inverter 210 is formed of a general three-phase inverter, and includes a U-phase arm, a V-phase arm, and a W-phase arm connected in parallel between power lines 190 and 195. Each of the U-phase arm, the V-phase arm, and the W-phase arm has two switching elements (upper arm element and lower arm element) connected in series. An antiparallel diode is connected to each switching element.

  First MG 110 has a star-connected U-phase coil, V-phase coil, and W-phase coil as stator windings. One end of each phase coil is connected to each other at a neutral point 112. The other end of each phase coil is connected to the connection point of the switching element of each phase arm of first inverter 210.

  When the vehicle travels, the first inverter 210 has the first MG 110 in accordance with an operation command value (typically a torque command value) set to generate an output (vehicle drive torque, power generation torque, etc.) required for vehicle travel. The current or voltage of each phase coil of the first MG 110 is controlled so as to operate. First inverter 210 converts a DC power supplied from battery 150 into an AC power and supplies it to first MG 110, and a power conversion operation that converts the AC power generated by first MG 110 into DC power. Bidirectional power conversion can be performed.

  Similar to the first inverter 210, the second inverter 220 is configured by a general three-phase inverter. Similar to first MG 110, second MG 120 has a U-phase coil, a V-phase coil, and a W-phase coil connected in a star shape as stator windings. One end of each phase coil is connected to each other at a neutral point 122. The other end of each phase coil is connected to the connection point of the switching element of each phase arm of second inverter 220.

  When the vehicle travels, the second inverter 220 is a second MG 120 according to an operation command value (typically a torque command value) set to generate an output (vehicle drive torque, regenerative braking torque, etc.) required for vehicle travel. The current or voltage of each phase coil of the second MG 120 is controlled so as to operate. Also for second inverter 220, a power conversion operation for converting DC power supplied from battery 150 into AC power and supplying it to second MG 120, and a power conversion operation for converting AC power generated by second MG 120 into DC power, Bidirectional power conversion can be performed.

  As will be described in detail later, first inverter 210 and second inverter 220 convert the AC voltage between neutral points 112 and 122 into a DC voltage in the external charging mode in which battery 150 is charged by an external power source. To be controlled. That is, the AC voltage from the external power supply 402 is converted into a DC voltage by the reactor component of each of the first MG 110 and the second MG 120 (inductance of each phase coil winding) and the first inverter 210 and the second inverter 220, and the power line 190 , 195 to output a “charging power conversion device”.

  At this time, each element included in the charging path in the electrical system shown in FIGS. 3 and 4 and ECU 170 that controls the operation of the power storage mechanism charging system according to the present embodiment are configured.

  In each of inverters 210 and 220, a set of U-phase coil and U-phase arm, a set of V-phase coil and V-phase arm, and a set of W-phase coil and W-phase arm have the same configuration as converter 200. Therefore, it is understood that the first inverter 210 and the second inverter 220 can also perform voltage conversion in which the voltages at the neutral points 112 and 122 are boosted and output to the converter 200 side. For example, when the battery 150 is charged with power supplied from a power supply outside the vehicle, the first inverter 210 and the second inverter 220 boost the voltage. For example, 100 VAC can be boosted and converted to a DC voltage of about 200V.

  SMR (System Main Relay) 250 is provided between battery 150 and converter 200 and DC / DC converter 230. The SMR 250 is a relay that switches between a state where the battery 150 and the electrical system are connected and a state where the battery 150 is disconnected. When SMR 250 is opened, battery 150 is disconnected from the electrical system. On the other hand, when SMR 250 is closed, battery 150 is connected to the electrical system. The state of SMR 250 is controlled by ECU 170. For example, the SMR 250 is closed in response to an ON operation of a power-on switch (not shown) instructing system activation of a plug-in hybrid vehicle, while the SMR 250 is in response to an OFF operation of the power-on switch. Opened.

  DC / DC converter 230 is connected to battery 150 in parallel with converter 200. DC / DC converter 230 steps down the DC voltage output from battery 150. The auxiliary battery 240 is charged with the output voltage of the DC / DC converter 230. The electric power charged in the auxiliary battery 240 is supplied to the auxiliary machine 242 such as an electric oil pump and the ECU 170.

Next, a configuration for external charging will be described.
A DFR (Dead Front Relay) 260 is inserted and connected to power supply lines 290 and 295 that electrically connect the neutral point 112 of the first MG 110 and the neutral point 122 of the second MG 120 and an external power source (FIG. 4). Is done. That is, DFR 260 is a relay (switching device) that switches connection / disconnection between the electrical system of the plug-in hybrid vehicle and the external power supply. When DFR 250 is opened, the electrical system of the plug-in hybrid vehicle is cut off from the external power source. On the other hand, when DFR 250 is closed, the electrical system of the plug-in hybrid vehicle is connected to an external power source.

  Connector 270 is provided, for example, on the side of a plug-in hybrid vehicle. As will be described later, the connector 270 is connected to a connector of a charging cable that connects the plug-in hybrid vehicle and the external power source. The LC filter 280 is provided between the DFR 260 and the connector 270.

The configuration for external charging will be described in more detail with reference to FIG.
Referring to FIG. 4, charging cable 300 that connects the plug-in hybrid vehicle and the external power source includes a connector 310, a plug 320, and a CCID (Charging Circuit Interrupt Device) 330. Charging cable 300 corresponds to EVSE (Electric Vehicle Supply Equipment) in the standards established in Non-Patent Documents 1 and 2.

  Connector 310 of charging cable 300 is connected to connector 270 provided in the plug-in hybrid vehicle. The connector 310 is provided with a switch 312. When the switch 312 is closed while the connector 310 of the charging cable 300 is connected to the connector 270 provided in the plug-in hybrid vehicle, the connector 310 of the charging cable 300 is connected to the connector 270 provided in the plug-in hybrid vehicle. Connector signal CNCT indicating that the state has been achieved is input to ECU 170.

  The switch 312 opens and closes in conjunction with a latch (not shown) that latches the connector 310 of the charging cable 300 to the connector 270 of the plug-in hybrid vehicle. The locking metal fitting (not shown) swings when an operator presses a button (not shown) provided on the connector 310.

  For example, when the operator releases the button while the connector 310 of the charging cable 300 is connected to the connector 270 provided on the plug-in hybrid vehicle, the locking bracket is provided on the plug-in hybrid vehicle. And the switch 312 is closed. When the operator presses the button, the engagement between the locking fitting and the connector 270 is released, and the switch 312 is opened. The method for opening and closing the switch 312 is not limited to this.

  Plug 320 of charging cable 300 is connected to an outlet 400 provided in the house. AC power is supplied to the outlet 400 from an external power supply 402 of the plug-in hybrid vehicle.

  The CCID 330 has a relay 332 and a control pilot circuit 334. When the relay 332 is opened, the path for supplying power from the external power supply 402 of the plug-in hybrid vehicle to the plug-in hybrid vehicle is blocked. When the relay 332 is closed, power can be supplied from the external power supply 402 of the plug-in hybrid vehicle to the plug-in hybrid vehicle. The state of relay 332 is controlled by ECU 170 in a state where connector 310 of charging cable 300 is connected to connector 270 of the plug-in hybrid vehicle.

  The control pilot circuit 334 is connected to the control pilot line when the plug 320 of the charging cable 300 is connected to the outlet 400, that is, the external power source 402, and the connector 310 is connected to the connector 270 provided in the plug-in hybrid vehicle. Send signal (square wave signal) CPLT.

  The pilot signal is oscillated from an oscillator provided in the control pilot circuit 334. The pilot signal is output or stopped with a delay corresponding to the delay in the operation of the oscillator.

  When the plug 320 of the charging cable 300 is connected to the outlet 400, the control pilot circuit 334 can output a constant pilot signal CPLT even if the connector 310 is disconnected from the connector 270 provided in the plug-in hybrid vehicle. . However, ECU 170 cannot detect pilot signal CPLT output with connector 310 disconnected from connector 270 provided in the plug-in hybrid vehicle.

  When plug 320 of charging cable 300 is connected to outlet 400 and connector 310 is connected to connector 270 of the plug-in hybrid vehicle, control pilot circuit 334 causes pilot signal CPLT having a predetermined pulse width (duty cycle). Oscillates.

  The plug-in hybrid vehicle is notified of the current capacity that can be supplied based on the pulse width of pilot signal CPLT. For example, the current capacity of charging cable 300 is notified to the plug-in hybrid vehicle. The pulse width of pilot signal CPLT is constant without depending on the voltage and current of external power supply 402.

  On the other hand, if the type of charging cable used is different, the pulse width of pilot signal CPLT may be different. That is, the pulse width of pilot signal CPLT can be determined for each type of charging cable.

  In the present embodiment, in external charging mode, battery 150 is charged with electric power supplied from external power supply 402 in a state where plug-in hybrid vehicle and external power supply 402 are connected by charging cable 300.

  A voltage sensor 171 for detecting an output voltage (AC voltage) of the external power supply 402 is provided on the power supply lines 290 and 295 electrically connected to the external power supply 402 by the charging cable 300 and the connector 270. Note that a plurality of voltage sensors 171 may be arranged in parallel for backup.

  The voltage Vac between the feed lines 290 and 295 detected by the voltage sensor 171 is sent to the ECU 170. In addition, a current sensor 173 is provided in at least one of the power supply lines 290 and 295, and the detected current Iac is sent to the ECU 170.

(Control in external charging mode)
FIG. 5 is a flowchart illustrating an outline of an operation procedure in the external charging mode of the charging system for the power storage mechanism according to the embodiment of the present invention.

  Referring to FIG. 5, in the external charging mode, ECU 170 first performs system activation confirmation in step S100. In step S100, based on the pilot signal CPLT, the connector signal CNCT, and the power-on signal, it is determined whether or not the preparation for starting the charging operation by the external power supply is ready. While step S100 is NO, the subsequent processing is not executed and the charging operation does not proceed.

  When the system activation is confirmed (YES in S100), ECU 170 closes SMR 250 after opening DFR 260 in step S110. Then, with the DFR 260 opened, the pre-charge boosting operation is performed in step S120 in a state where the power supply from the external power supply 402 is shut off. Further, when the pre-charge boosting operation is completed, ECU 170 closes DFR 260 in step S130. Thereby, the external power source 402 and the neutral points 112 and 122 are electrically connected, and the power supplied from the external power source 402 is guided into the electrical system of the plug-in hybrid vehicle.

  Subsequently, in step S140, ECU 170 executes a voltage balance condition search operation to obtain DC voltage VH on power line 195 that balances with the DC voltage obtained by converting the external power supply voltage by first inverter 210 and second inverter 220. Ask. Hereinafter, the DC voltage VH at this time is also referred to as a balanced voltage VH *.

  When the balanced voltage VH * is determined, the ECU 170 starts the charging operation in a state where the DC voltage VH is lower than the balanced voltage VH * in step S150 until the battery 150 is charged to a desired level. During this time, the charging operation is executed.

Next, voltage-current behavior in each operation of FIG. 5 will be described with reference to FIG.
Referring to FIG. 6, in the period T1 up to time t1, the pre-charge boosting operation in step S120 (FIG. 5) is executed. That is, since DFR 260 is open, DC voltage VH is increased by increasing target voltage VR of converter 200 while current Iac = 0. The target value VHmax (upper limit voltage) of the DC voltage VH in the pre-charging boosting operation is expressed by, for example, the following equation (1), assuming that the external power supply voltage VAC = Va · sinωt, which is the output voltage of the external power supply 402.

VHmax = Va · √2 + Vh (1)
In Expression (1), the voltage Vh is a voltage corresponding to the maximum error of the voltage sensor 180. Voltage Va · √2 is the maximum value of the DC voltage output by the rectification operation by the antiparallel diodes of inverters 110 and 120. The voltage Va is preferably determined corresponding to the maximum voltage (effective value) that can be assumed by the external power supply 402 in consideration of the difference in the rated voltage of the commercial AC power supply in each country.

  As a result, by setting VH = VHmax, it is ensured that an excessive inrush current is generated inside the electric system due to the voltage difference between the output voltage of the external power supply 402 and the system voltage VH in response to the closing of the DFR 260. Can be prevented.

  When VH = VHmax is set, at time t1, DFR 260 is closed corresponding to step S130 (FIG. 5), and the voltage balance condition search operation shown in step S140 (FIG. 5) is performed at times t1 to t2. In the period T2.

  In period T2, target voltage VR of converter 200 is gradually decreased from upper limit voltage VHmax, and system voltage VH is decreased accordingly. At time t1, since system voltage VH (VH = VHmax) is higher than the output voltage of inverters 110 and 120, current Iac on feeder line 290 flows in the direction of flowing into external power supply 402. That is, the peak value of the current Iac is a negative value. As the system voltage VH decreases, the peak value of the current Iac increases, and the current Iac flowing into the external power supply 402 gradually decreases.

  Further, at time t2, system voltage VH and the output voltages of inverters 110 and 120 are in balance. For example, when the peak value of the current Iac changes from a negative value to zero, it can be detected that the state is balanced as described above. By determining the system voltage VH at this time as the balanced voltage VH *, the voltage balanced condition search operation is terminated.

  When the voltage balance condition search operation is finished at time t2, converter 200 is controlled to further lower system voltage VH from balanced voltage VH * in preparation for charging operation in period T3 from time t2 to t3. The In a period T4 after time t3, the external power supply voltage is converted into a DC voltage and output to the power line 190 with the system voltage VH <VH *, and the DC voltage on the power line 190 is converted by the converter 200 to the battery 150. The battery 150 is charged by performing a voltage conversion operation for converting to a charging voltage of.

  The duty of the switching elements of the inverters 110 and 120 is feedback-controlled so that electric power according to the command value is supplied from the external power source 402 in the period T4 during which the charging operation is performed, as will be described later.

  On the other hand, during the voltage balance condition search operation (period T2), the current Iac only needs to be at a level at which the current sensor 193 can detect the reversal of the current direction. Therefore, the duty is fixed to a value required to flow a current at the lowest level necessary for detection as described above without being feedback-controlled. Basically, at this time, the boosting operation in the inverters 210 and 220 is not executed, and the balanced voltage VH * at this time corresponds to the amplitude value (peak value) Vacp of the external power supply voltage. .

  FIG. 7 is a functional block diagram illustrating a control configuration of the external charging control unit for executing the external charging mode described in FIGS. 5 and 6. The function of each block shown in FIG. 7 can be realized by hardware or software processing of the ECU 170.

  Referring to FIG. 7, external charge control unit 1000 includes a precharge boosting unit 1010, a relay control unit 1020, a voltage balance condition searching unit 1030, a charge control unit 1040, a correction gain setting unit 1050, and an abnormality detection. Part 1060.

  The pre-charging boosting unit 1010 performs the pre-charging boosting operation in the period T1 in FIG. 6 based on the mode signal MD indicating the external charging mode. For example, mode signal MD is turned on when step S100 in FIG. 5 is YES.

  Pre-charging booster 1010 sets target voltage VR of converter 200 to upper limit voltage VHmax during the pre-charging boost operation. Note that when the target voltage VR is set to the upper limit voltage VHmax, the target voltage VR may be gradually increased based on the current value of the system voltage VH.

  When the DC voltage VH detected by the voltage sensor 180 reaches the upper limit voltage VHmax, the pre-charging booster 1010 turns on the flag FL1 for notifying that the pre-charging boosting operation has been completed.

  When the mode signal MD is turned on, the relay control unit 1020 generates the control signal SDFR so as to open the DFR 260. Then, when the pre-charging boosting unit 1010 turns on the flag FL1 indicating that the pre-charging boosting operation has been completed, the control signal SDFR is generated so as to close the DFR 260. Then, in response to the completion of the pre-charging boost operation, the flag FL2 for notifying that the DFR 260 is closed is turned on.

  In the configuration shown in FIG. 4, when the DFR 260 is closed, the DFR 260 is closed with the CCID relay 332 open, and then the CCID relay 332 is closed in order to perform self-diagnosis of the DFR 260. There is a need. Further, when it is necessary to detect the external power supply voltage by the voltage sensor 171 in order to prevent the occurrence of overcurrent at the start of the charging operation, the CCID relay 332 is closed before the DFR 260 is closed. Thus, it is necessary to electrically connect between the feeder lines 290 and 295 and the external power source 402. In other words, as in the present embodiment, by performing the pre-charging boosting operation and the voltage balance condition searching operation, the charging operation can be stably started without measuring the external power supply voltage by the voltage sensor 171. Since the number of times of opening / closing the CCID relay 332 can be reduced by one per external charging mode, the durability performance can be improved.

  When the flag FL2 is turned on by the relay control unit 1020, the voltage balance condition search unit 1030 sets the duty of the inverters 210 and 220 to the fixed duty described with reference to FIG. Switching control signals SIV1 and SIV2 whose timing is fixed are generated. Further, voltage balance condition search unit 1030 gradually reduces target voltage VR of converter 200 from VHmax during the pre-charging boost operation in a state where inverters 210 and 220 are controlled to a fixed duty.

  Further, the voltage balance condition search unit 1030 starts the voltage balance condition search operation based on the current Iac detected by the current sensor 193 each time the target voltage VR is decreased by ΔVR. It is determined whether or not the direction has changed from the direction of time (the direction in which the external power supply 402 flows into the power supply lines 290 and 295).

  Then, the system voltage VH and the output voltages of the inverters 110 and 120 are balanced, and the DC voltage VH when the current Iac≈0 is stored as the balanced voltage VH *. The balanced voltage VH * may be the target voltage VR at this time, or may be determined based on the detection voltage VH detected by the voltage sensor 180. Then, the voltage balance condition search unit 1030 may turn on the flag FL3 for notifying that the determination of the balance voltage VH * is completed.

  When the flag FL3 is turned on, the correction gain setting unit 1050 obtains a voltage ratio between the balanced voltage VH * and the peak value of the voltage Vac at that time (that is, the peak value of the external power supply voltage), and based on this voltage ratio Thus, the voltage correction gain kv is determined. As described above, the correction gain kv based on the voltage ratio Vacp / VH * is a value corresponding to the measurement error of the voltage sensor 171. That is, the voltage correction gain kv is kv = 1.0 when the voltage sensor 171 has no error.

  Therefore, the abnormality detection unit 1060 detects that an abnormality has occurred in the voltage sensor 171 when the voltage correction gain kv is kv >> 1.0 or kv << 1.0. Then, assuming that an abnormality has been detected in the voltage sensor 171, the charging stop flag STP for prohibiting the charging operation is turned on.

  Charging control unit 1040 controls converter 200 and inverters 210 and 220 so that battery 150 is charged by the power supplied from external power supply 402 when flag FL3 is turned on by voltage balance condition searching unit 1030. However, when the abnormality detection unit 1060 turns on the charging stop flag STP, the charging control unit 1040 is configured not to start the charging operation even if the flag FL3 is turned on.

  When flag FL3 is turned on, charging control unit 1040 reduces target voltage VR of converter 200 so that system voltage VH is lower than balanced voltage VH * in order to realize the operation in period T3 in FIG. Let Then, under such system voltage VH, feedback control based on voltage Vac detected by voltage sensor 171 and current Iac detected by current sensor 173 causes battery 150 to be charged according to charge command PWR. In order to control the duty of inverters 210 and 220, switching control signals SIV1 and SIV2 are generated.

  Next, details of step S140 for executing the voltage balance condition search shown in FIG. 5 will be described with reference to FIG. The flowchart shown in FIG. 8 corresponds to processing for realizing the functions of the voltage balance condition search unit 1030, the correction gain setting unit 1050, and the abnormality detection unit 1060 shown in FIG.

  Referring to FIG. 8, ECU 170 determines in step S200 whether system voltage VH has reached upper limit voltage VHmax. If the pre-charge boosting operation in step S120 (FIG. 5) has been normally executed, step S200 is determined as YES. On the other hand, when system voltage VH is lower than upper limit voltage VHmax, ECU 170 sets target voltage VR to increase system voltage VH to upper limit voltage VHmax in step S205, and then again in step S200. Make a decision.

  When it is confirmed that VH ≧ VHmax is satisfied (when YES is determined in S200), ECU 170 confirms whether current sensor 173 is abnormal by checking the peak value of current Iac detected by current sensor 173 in step S210. . For example, if the peak value of Iac at this time is equal to or larger than a predetermined value (during NG determination in S210), ECU 170 determines that an abnormality has occurred in current sensor 193, and proceeds to step S290. When the current sensor 173 is abnormal, it is difficult to normally control the external charging operation according to the charging command. Therefore, in step S290, the ECU 170 detects a system abnormality and stops the external charging operation in an emergency manner.

  On the other hand, when current Iac is normal (when OK is determined in step S210), ECU 170 causes step S220 to determine the voltage ratio between current system voltage VH and peak value Vacp of voltage Vac detected by voltage sensor 171 ( Based on Vacp / VH), a voltage correction gain kv is calculated. As an example, it is assumed here that kv = Vacp / VH.

  Further, ECU 170 proceeds to step S230 to determine whether or not the peak value of current Iac is equal to or greater than 0, and the current direction on feeder line 290 is the direction at the start of the voltage balance condition search operation. It is determined whether or not the direction has changed from the direction in which the external power supply 402 flows into the power supply lines 290 and 295.

  When peak value of current Iac <0 (NO determination in S230), ECU 170 has converter 200 because system voltage VH is higher than the DC voltage obtained by inverters 110 and 120 converting the external power supply voltage (AC). The system voltage VH is lowered by lowering the target voltage VR (step S240). Specifically, the target voltage VR is reduced by ΔVR from the previous value and updated to VR−ΔVR.

  Here, regarding the amount of decrease ΔVR of the target voltage VR per time, as shown in FIG. 9, the voltage difference between the DC voltage VH (or the target voltage VR) and the peak value Vacp of the detection voltage Vac at this time It is also possible to variably set based on the above.

  As shown in FIG. 9, when the voltage difference VH−Vacp (or VR−Vacp) is large, the amount of voltage decrease required to decrease the system voltage VH to the balanced voltage VH * is large, and thus the target voltage ΔVR Is set relatively large so that the system voltage VH is brought close to the balanced voltage VH * quickly. On the other hand, when the voltage difference is small, the balanced voltage VH * can be set more accurately by setting the target voltage ΔVR to be relatively small.

  Referring to FIG. 8 again, ECU 170 decreases target voltage VR by ΔVR in step S240, and then determines whether target voltage VR has reached the lower limit value in step S250. The lower limit value in S250 is set, for example, corresponding to the minimum voltage that can be assumed of the output voltage amplitude of external power supply 402.

  On the other hand, when system voltage VH is reduced to a state in which the system voltage VH is balanced with the output voltages of inverters 110 and 120, the peak value of current Iac changes to 0 (when YES is determined in S230), ECU 170 The process proceeds to step S260.

  On the other hand, until the peak value of current Iac is reversed (when NO is determined in step S230), the processes of steps S220 to S250 are repeatedly executed until current Iac is reversed, that is, system voltage VH. Until system voltage VH is balanced with the output voltages of inverters 110 and 120, system voltage VH is gradually decreased.

  In step S260, ECU 170 sets target voltage VR or voltage detected by voltage sensor 180 (system voltage VH) to balanced voltage VH *. Further, the voltage correction gain kv is determined based on the voltage ratio Vacp / VH at this time.

  Further, in step S270, ECU 170 determines whether or not voltage correction gain kv (originally kv = 1.0) determined in step S260 is kv >> 1.0 or kv << 1.0. To do. For example, in step S270, kv> 1.0 + α (α: determination value) (kv >> 1.0) or kv <1.0−β (β: determination value) (kv << 1.0), it is determined that the voltage sensor 171 is abnormal. If the determination in step S270 is YES, ECU 170 detects a system abnormality in step S290, and emergency-stops the external charging operation. That is, the charging operation as in the period T4 in FIG. 6 is not executed.

  On the other hand, when voltage correction gain kv (voltage ratio) is within the normal range (when NO is determined in S270), ECU 170 turns on the charging operation permission flag in step S280. This charging operation permission flag corresponds to the flag FL3 shown in FIG.

  Next, the charging operation in step S150 of FIG. 5, that is, the external charging control by the charging control unit 1040 shown in FIG. 7 will be described with reference to FIGS.

  Referring to FIG. 10, charging control unit 1040 includes a Vac correction unit 1080, a charging command generation unit 1090, and an inverter control unit 1100. The inverter control unit 1100 is a functional block that generates the switching control signals SIV1 and SIV2 of the inverters 210 and 220 in the external charging mode.

  Vac correction unit 1080 calculates voltage Vac # used for charge control in the external charge mode based on voltage Vac detected by voltage sensor 171 and voltage correction gain kv set by correction gain setting unit 1050. .

  As shown in FIG. 11, voltage Vac # used for charging control is calculated by multiplying measured value Vac by voltage sensor 171 by voltage correction gain kv. Thereby, even if an error occurs in the voltage sensor 171, the error can be corrected and the charging operation in the external charging mode can be controlled.

  Referring to FIG. 10 again, charging command generation unit 1090 generates charging command PWR for battery 150. Charging command PWR includes, for example, charging current command value RC. The charge command PWR is basically determined based on the EVSE rated current and the like. Alternatively, the charging command PWR may be variably set in accordance with the state of the battery 150, reflecting the state of charge (SOC) and temperature of the battery.

  Inverter control unit 1100 supplies the charging power of battery 150 from external power supply 402 according to charge command PWR by feedback control using voltage Vac # obtained by Vac modification unit 1080 and current Iac detected by current sensor 173. As described above, the switching control signals SIV1 and SIV2 of the inverters 210 and 220 are generated.

  Next, a specific example of inverter control by the inverter control unit 1100 will be described with reference to FIGS. 12 and 13.

FIG. 12 is a functional block diagram for explaining inverter control in the external charging mode.
Referring to FIG. 12, external charge control unit 600 includes a phase detection unit 610, a sine wave generation unit 620, a multiplication unit 630, a subtraction unit 640, and a current control unit 650.

  Phase detector 610 detects a zero cross point of voltage Vac, and detects the phase of voltage Vac based on the detected zero cross point. The sine wave generation unit 620 generates a sine wave in phase with the voltage Vac based on the phase of the voltage Vac detected by the phase detection unit 610. The sine wave generation unit 620 can generate a sine wave in phase with the voltage Vac based on the phase information from the phase detection unit 610 using, for example, a table of sine wave functions.

  Multiplier 630 multiplies charging current command value RC by the sine wave from sine wave generation unit 620 and outputs the calculation result as a current command value. Subtraction unit 640 subtracts current Iac detected by current sensor 173 from the current command output from multiplication unit 630, and outputs the calculation result to current control unit 650.

  The current control unit 650 is based on the deviation between the current command output from the multiplication unit 630 and the current Iac detected by the current sensor 173 when the mode signal MD indicating the external charging mode is turned on. A zero-phase voltage command E0 for causing the current Iac to follow the current command is generated. The zero-phase voltage command E0 is a voltage that is uniformly added to at least one of the first inverter 210 and the second inverter 220. The zero-phase voltage command E0 itself is the first MG110 and the second MG120. It does not contribute to the rotational torque.

  FIG. 13 is a diagram showing a zero-phase equivalent circuit of first and second inverters 210 and 220 and first and second MGs 110 and 120 shown in FIG. Each of first and second inverters 210 and 220 is formed of a three-phase bridge circuit as shown in FIG. 3, and there are eight patterns of ON / OFF combinations of six switching elements in each inverter. Two of the eight switching patterns have zero interphase voltage, and such a voltage state is called a zero voltage vector. For the zero voltage vector, the three switching elements of the upper arm can be regarded as the same switching state (all on or off), and the three switching elements of the lower arm can also be regarded as the same switching state.

  When the battery 150 is charged by the external power source 402, the zero voltage vector is controlled in at least one of the first and second inverters 210 and 220 based on the zero-phase voltage command E0 generated by the external charge control unit 600 (FIG. 12). Is done. Therefore, in FIG. 13, the three switching elements of the upper arm of the first inverter 210 are comprehensively described as the upper arm 210A, and the three switching elements of the lower arm of the first inverter 210 are comprehensively described as the lower arm 210B. be written. Similarly, the three switching elements of the upper arm of the second inverter 220 are generically described as an upper arm 220A, and the three switching elements of the lower arm of the second inverter 220 are generically described as a lower arm 220B.

  As shown in FIG. 13, this zero-phase equivalent circuit is a single-phase PWM that receives the single-phase AC power supplied from the external power source 402 to the neutral point 112 of the first MG 110 and the neutral point 122 of the second MG 120. It can be seen as a converter. Therefore, the zero voltage vector is changed based on the zero phase voltage command E0 in at least one of the first and second inverters 210 and 220 so that the first and second inverters 210 and 220 operate as an arm of the single phase PWM converter. By performing switching control, the AC power supplied from the external power source 402 can be converted into a DC voltage for charging the battery 150.

  The inverter control in the external charging mode shown in FIGS. 12 and 13 is merely an example, and in the application of the present invention, an inverter that converts the power supplied from the external power source 402 into the charging power of the battery 150 (power storage mechanism). The point of control is not particularly limited, and will be described in a confirming manner.

  As described above, according to the charging system of the power storage mechanism according to the embodiment of the present invention, the system voltage VH is raised to the upper limit voltage VHmax by the boosting operation before charging, so that the inrush from the external power supply 402 is performed when the DFR 260 is closed. While reliably preventing current from being generated, the charging operation can be started stably without causing overcurrent. Furthermore, the charging operation can be performed in a state where the system voltage VH is lowered to the equilibrium voltage VH * or less to a voltage level that does not require excessive boosting of the external power supply voltage. As a result, it is possible to reliably prevent the occurrence of an excessive current without depending on the detection of the external power supply voltage and without reducing the efficiency during charging.

  Furthermore, the measurement accuracy of the voltage sensor 171 can be evaluated by obtaining the balanced voltage VH * by the voltage balance condition search operation. In particular, by performing feedback control reflecting the voltage correction gain kv determined based on the voltage ratio Vacp / VH *, it is possible to improve the accuracy of charge control in the external charge mode. Alternatively, when it is detected that the error of the voltage sensor 171 is excessive based on the voltage ratio, it is possible to prevent a trouble beforehand by stopping the charging operation.

  In the present embodiment, external power source 402 is connected to neutral points 112 and 122, and the reactor components of first MG 110 and second MG 120 (inductance of each phase coil winding), first inverter 210 and second inverter 220 illustrates the configuration in which AC power from the external power source 402 is converted into charging power for the battery 150 (power storage mechanism). However, the application of the present invention is not limited to such a configuration, and an AC voltage from the external power source 402 is applied between the power supply lines 290 and 295 (inside the DFR 260 inside the vehicle) and the power lines 190 and 195. The present invention can also be applied to a plug-in vehicle having a configuration in which a power converter (not shown) dedicated to external charging that changes to a DC voltage is separately arranged.

  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.

It is a schematic block diagram which shows a plug-in hybrid vehicle. It is a figure which shows the alignment chart of a power split device. It is a figure (the 1) which shows the electric system of a plug-in hybrid vehicle. It is FIG. (2) which shows the electrical system of a plug-in hybrid vehicle. It is a flowchart explaining the outline | summary of the operation | movement procedure in the external charge mode of the charging system of the electrical storage mechanism by embodiment of this invention. It is a wave form diagram for demonstrating roughly the voltage-current behavior in the external charge mode of the charging system of the electrical storage mechanism by embodiment of this invention. It is a functional block diagram explaining the control structure of the external charge control part for performing the external charge mode demonstrated in FIG. 5 and FIG. It is a flowchart explaining the detail of the step for performing the voltage balance condition search shown in FIG. It is a conceptual diagram explaining the example of a setting of the fall amount of the target voltage at the time of voltage balance condition search. It is a block diagram explaining the structure of the charge control part shown in FIG. It is a conceptual diagram explaining the correction of the voltage used for the charge control using a voltage correction gain. It is a functional block diagram explaining inverter control at the time of external charge mode. It is the figure which showed the zero-phase equivalent circuit of the 1st and 2nd inverter and 1st and 2nd MG at the time of external charge mode.

Explanation of symbols

  100 Engine, 110 1st MG, 112 Neutral point (1st MG), 120 2nd MG, 122 Neutral point (2nd MG), 130 Power split mechanism, 140 Reducer, 150 Battery (power storage mechanism), 160 Front wheel, 170 ECU , 171 Voltage sensor (Vac), 173 Current sensor, 180 Voltage sensor (VH), 190, 195 Power line, 200 Converter, 210 Inverter (first MG), 220 Inverter (second MG), 210A, 220A Upper arm, 210B, 220B Lower arm, 230 DC / DC converter, 240 Auxiliary battery, 242 Auxiliary machine, 250 SMR, 260 DFR (switching device), 270 connector (vehicle), 280 LC filter, 290,295 Feed line, 300 Charging cable, 310 connector (Charging cable 312 switch, 320 plug, 332 relay, 334 control pilot circuit, 400 outlet, 402 external power supply, 510 DFR control unit, 520 inverter control unit, 530 DFR abnormality detection unit, 600 external charge control unit, 610 phase detection unit , 620 sine wave generation unit, 630 multiplication unit, 640 subtraction unit, 650 current control unit, 1000 external charge control unit, 1010 pre-charge boost unit, 1020 relay control unit, 1030 voltage balance condition search unit, 1040 charge control unit, 1050 Correction gain setting unit, 1060 abnormality detection unit, 1080 Vac correction unit, 1090 charge command generation unit, 1100 inverter control unit, CNCT connector signal, CPLT pilot signal, E0 zero phase voltage command, FL1-FL3 flag, Iac current (AC ), Kv voltage correction gain, MD mode signal (external charging mode), RC charging current command value, PWR charging command, SDFR control signal (DFR), SIV1, SIV2 switching control signal, STP charging stop flag, T1 period (before charging) Step-up operation), T2 period (voltage balance condition search operation), T3 period (charge preparation operation), T4 period (charge operation), VAC external power supply voltage, Vac voltage (sensor measured value), Vac # voltage (control use value) , Vacp peak value (external power supply voltage), VH DC voltage (system voltage), VH * equilibrium voltage, VHmax upper limit voltage, VR target voltage, ΔVR target voltage drop amount.

Claims (14)

A charge control system for a power storage mechanism mounted on an electric vehicle,
A converter configured to be capable of bi-directional power conversion between the power storage mechanism and the power line, and controlling a voltage of the power line to a target voltage;
In an external charging mode in which the power storage mechanism is charged by an external power source of the electric vehicle, a power supply line electrically connected to the external power source via a connector;
A current detector for detecting a current flowing through the feeder line;
A switchgear connected to the feeder line;
A charging power conversion device that is provided between the power supply line and the power line, converts an AC voltage from the external power source into a DC voltage, and outputs the DC voltage to the power line;
A control device for controlling the operation of the charging control system in the external charging mode,
The controller is
A pre-charging booster that sets the target voltage to a predetermined voltage higher than the highest voltage that the charging power conversion device converts the AC voltage and outputs to the power line in a state where the switchgear is opened;
After the power line is set to the predetermined voltage by the pre-charging booster, the switchgear is closed, and further, by monitoring the current detected by the current detector while gradually reducing the target voltage, A voltage balance condition determination unit that determines an equilibrium voltage that is the target voltage when the output voltage of the charging power converter is equal to the voltage on the power line;
A charging control unit configured to charge the power storage mechanism by setting the target voltage to be equal to or lower than the balanced voltage and controlling the operation of the charging power conversion device according to a charge command for the power storage mechanism. system. A voltage detector for detecting a voltage on the feeder line;
The controller is
The charge control system for a power storage mechanism according to claim 1, further comprising a gain setting unit that calculates a correction gain of the detection voltage based on a voltage ratio between the balanced voltage and a peak value of the detection voltage detected by the voltage detector.   The power storage mechanism according to claim 2, wherein the charge control unit controls the operation of the charge power conversion device according to feedback control based on a detection current detected by the current detector and the detection voltage corrected according to the correction gain. Charging control system. The controller is
When the voltage ratio is higher than a first predetermined value larger than 1.0, or when the voltage ratio is lower than a second predetermined value smaller than 1.0, an abnormality of the charge control system is detected, and The charge control system for a power storage mechanism according to claim 2, further comprising an abnormality detection unit that stops the external charging operation. A voltage detector for detecting a voltage on the feeder line;
The voltage balance condition determination unit variably sets a voltage drop amount per time when the target voltage is gradually reduced according to a difference between the target voltage and a peak value of a detection voltage by the voltage detector. The charge control system for a power storage mechanism according to claim 1. A voltage detector for detecting a voltage on the feeder line;
The charging power conversion device includes an inverter composed of a plurality of power semiconductor switching elements,
The control device turns on and off the plurality of power semiconductor switching elements in accordance with a predetermined switching pattern when searching for the balanced voltage by the voltage balance condition determining unit, and at the time of charging operation by the charge control, the current detector The charge control system for a power storage mechanism according to claim 1, wherein on / off of the plurality of power semiconductor switching elements is controlled according to feedback control based on a detection value by the voltage detector. 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;
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;
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 for generating a driving force for driving the electric vehicle,
In the external charging mode, the power supply line is connected to the first neutral point of the first multiphase winding and the second middle of the second multiphase winding via the connector and the charging cable. Arranged to electrically connect the sex point and the external power source,
In the external charging mode, the inverter control device is configured to allow the inductance of the first and second inverters and the first and second multiphase windings to operate as the charging power conversion device. 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 system for a power storage mechanism according to any one of claims 1 to 6, wherein each of the control units is controlled. A control method of a charge control system for a power storage mechanism mounted on an electric vehicle,
The charge control system includes:
A converter configured to be capable of bi-directional power conversion between the power storage mechanism and the power line, and controlling a voltage of the power line to a target voltage;
In an external charging mode in which the power storage mechanism is charged by an external power source of the electric vehicle, a power supply line electrically connected to the external power source via a connector;
A current detector for detecting a current flowing through the feeder line;
A switchgear connected to the feeder line;
A charging power conversion device that is provided between the power supply line and the power line, converts an AC voltage from the external power source into a DC voltage, and outputs the DC voltage to the power line;
The control method is:
Setting the target voltage to a predetermined voltage higher than the highest voltage that the charging power conversion device converts the AC voltage and outputs to the power line in a state in which the switching device is opened during the external charging mode;
After the power line is set to the predetermined voltage, closing the switchgear;
By monitoring the current detected by the current detector while gradually lowering the target voltage while the switchgear is closed, the output voltage of the charging power converter is equal to the voltage on the power line. Determining an equilibrium voltage that is the target voltage when
Charging the power storage mechanism by setting the target voltage below the equilibrium voltage and controlling the operation of the charging power conversion device according to a charge command for the power storage mechanism. Control method. The charge control system includes:
A voltage detector for detecting a voltage on the power supply line;
The control method is:
9. The control method for a charge control system for a power storage mechanism according to claim 8, further comprising a step of calculating a correction gain of the detection voltage based on a voltage ratio between the balanced voltage and a peak value of a detection voltage detected by the voltage detector. .   The power storage mechanism according to claim 9, wherein the charging step controls operation of the charging power converter according to feedback control based on a detection current by the current detector and the detection voltage corrected according to the correction gain. Charge control system control method.   When the voltage ratio is higher than a first predetermined value larger than 1.0, or when the voltage ratio is lower than a second predetermined value smaller than 1.0, an abnormality of the charge control system is detected, and The method for controlling a charging control system for a power storage mechanism according to claim 9, further comprising the step of stopping the external charging operation. The charge control system includes:
A voltage detector for detecting a voltage on the feeder line;
The determining step variably sets the amount of voltage decrease per time when the target voltage is gradually decreased according to the difference between the target voltage and the peak value of the detection voltage by the voltage detector. The control method of the charge control system of the electrical storage mechanism according to claim 8. The charge control system includes:
A voltage detector for detecting a voltage on the feeder line;
The charging power conversion device includes an inverter composed of a plurality of power semiconductor switching elements,
The plurality of power semiconductor switching elements are turned on / off in accordance with a predetermined switching pattern when searching for the balanced voltage in the determining step, while the current detector and the voltage detection are performed in a charging operation in the charging step. The control method of the charge control system of the electrical storage mechanism according to claim 8, wherein on / off is controlled according to feedback control based on a detection value by a battery. 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;
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;
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 for generating a driving force for driving the electric vehicle,
In the external charging mode, the power supply line is connected to the first neutral point of the first multiphase winding and the second middle of the second multiphase winding via the connector and the charging cable. Arranged to electrically connect the sex point and the external power source,
In the external charging mode, the inverter control device is configured to allow the inductance of the first and second inverters and the first and second multiphase windings to operate as the charging power conversion device. 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 control method of the charge control system of the electrical storage mechanism of any one of Claims 8-13 which controls each of these.

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