JP2014082825A - Charging and discharging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging and discharging device capable of determining the states of relays installed in each of a charging path and a discharging path by a simple and low-cost system configuration while commonalizing a cable.SOLUTION: A charging and discharging device includes: a charging path for charging an external device including a secondary battery from an external power supply; a charge relay for opening and closing the charging path; a discharging path for supplying power to a general load from the secondary battery of the external device; a discharge relay for opening and closing the discharging path; a control unit for open/close controlling each relay; a first voltage detection unit provided on the external power supply side of the charge relay; a second voltage detection unit commonly provided for each relay on the external device side of the charge relay and the discharge relay; and a third voltage detection unit provided on the general load side of the discharge relay.

Description

  The present invention relates to a charging / discharging device having a charging function for charging an external device including a secondary battery from an external power source, and a discharging function for discharging power from the secondary battery to supply power to another general load. It is.

  In the present invention, an external power source is a system power source owned by an electric power company, and an external device having a secondary battery is a large-sized storage battery for vehicles / power storage equipped with a large-capacity on-board battery such as EV / PHV. The general load means a 100V / 200V load device used at home or the like.

  In recent years, technology for supplying power to general loads using the power storage function of secondary batteries (hereinafter referred to as in-vehicle batteries) mounted on electric vehicles has attracted attention, and various technologies have been developed for charge / discharge systems using in-vehicle batteries. (For example, Patent Document 1). According to the charging / discharging system using the in-vehicle battery, for example, in each home or company, by charging the in-vehicle battery at midnight, by supplying power from the in-vehicle battery to a general load at the daytime power peak, It becomes possible to perform peak cutting of electric power.

  The conventional technology is premised on the use of a dedicated charging cable when charging an in-vehicle battery and the use of a dedicated discharging cable when discharging from the in-vehicle battery, while improving the convenience of the system and promoting its use. From the viewpoint, it is desirable to simplify the system and make the connection cable compatible with both charging and discharging.

  As shown in FIG. 1 and FIG. 2, a conventional charging device used exclusively for charging includes a CPLT circuit 4 for generating a charging control signal (CPLT signal) in the control unit 3 and a relay based on the CPLT signal. 5 for detecting the open / close state of the relay based on the signal from the voltage detector 7 arranged on each of the power supply side and the load side across the relay 5 Means 8 are provided. Among these, the determination means 6 receives the signal indicating the open / close state of the relay from the contact detection means 8 in addition to the function of transmitting the charging circuit open / close signal to the relay 5 based on the CPLT signal as described above. Determine the consistency with the signal, for example, as shown in Table 1 below, perform relay status determination, and display the relay welding or non-operating status on the display unit so that the user can grasp it. It has a function.

  For example, in a charge / discharge system using in-vehicle batteries, the above technology is also applied to the discharge circuit when it is assumed that a dedicated cable for charging is used when charging the in-vehicle battery and a dedicated discharge cable is used when discharging from the in-vehicle battery. Then, it is possible to determine the state of the relay incorporated in each of the charging electric circuit and the discharging electric circuit, and to display on the display unit so that the user can grasp the welding or non-operating state of each relay. .

  However, in this case, each of the charging circuit and the discharging circuit has a voltage detection unit disposed upstream and downstream of the relay, and contact detection that detects the open / closed state of the relay based on a signal from the voltage detection unit By providing the means, there is a problem that the system configuration becomes complicated and the cost is high, and there is a problem that connection cables used at the time of charging and discharging cannot be made common.

JP 2010-35277 A

  The object of the present invention is incorporated in each of the charging circuit and the discharging circuit with a simple and low-cost system configuration while solving the above-mentioned problems and realizing common connection cables used during charging and discharging. It is providing the charging / discharging apparatus which can determine the state of a relay.

  The charging / discharging device of the present invention made to solve the above problems is a charging circuit that charges an external device including a secondary battery from an external power source, a charging relay that opens and closes the charging circuit, and a secondary of the external device. A discharge circuit for supplying power from the battery to a general load; a discharge relay for opening and closing the discharge circuit; a control unit for controlling opening and closing of each relay; a first voltage detection unit provided on the external power supply side of the charge relay; The external device side of the relay and the discharge relay is provided with a second voltage detection unit provided in common to each relay, and a third voltage detection unit provided on the general load side of the discharge relay It is.

  According to a second aspect of the present invention, in the charging / discharging device according to the first aspect, the control unit detects an open / close state of each relay based on a detection signal from each voltage detection unit, and outputs an open / close signal to each relay. It has a judging means which transmits and judges the state of each relay based on consistency with the above-mentioned opening-and-closing signal.

  According to a third aspect of the present invention, in the charging / discharging device according to the second aspect, the determining means determines the state of the charging relay from the first voltage detecting unit and the second voltage detecting unit. A signal indicating the open / closed state of the discharge relay from the second voltage detecting unit and the third voltage detecting unit, This is performed based on consistency with an open / close signal for the relay.

  According to a fourth aspect of the present invention, in the charging / discharging device according to the second aspect, the control unit includes a management circuit that appropriately generates a mode switching signal in any one of a charging mode and a discharging mode, The state determination of each relay is performed based on a mode switching signal.

  According to a fifth aspect of the present invention, in the charge / discharge device according to the fourth aspect, among the determination of the state of the discharge relay, the relay welding determination is performed in a charging mode.

  In the charging / discharging device according to the present invention, a charging circuit for charging an external device having a secondary battery from an external power source, a charging relay for opening and closing the charging circuit, and a power source for supplying power to a general load from the secondary battery of the external device Discharge circuit, discharge relay for opening / closing the discharge circuit, control unit for controlling opening / closing of each relay, first voltage detection unit provided on the external power supply side of the charge relay, and external device side of the charge relay and discharge relay In the configuration including the second voltage detection unit provided in common to each relay and the third voltage detection unit provided on the general load side of the discharge relay, voltage detection is performed upstream and downstream of each of the charge relay and the discharge relay. The number of voltage detection units can be suppressed as compared with the case where the unit is provided. In addition, a management circuit that generates a mode switching signal as appropriate in either the charge mode or the discharge mode, and detects the open / closed state of each relay based on the detection signal from each voltage detection unit, and transmits the open / close signal to each relay By receiving a signal indicating the open / closed state of each relay and transmitting an open / close signal to each relay, it is simpler than a configuration in which a CPLT circuit, a determination unit, and a voltage detection unit are provided independently for each relay. In addition, a low-cost system configuration can be realized.

  The determination means performs the state determination of the charging relay based on the consistency between the signals from the first voltage detection unit and the second voltage detection unit and the open / close signal for the charge relay, and determines the state of the discharge relay, The state of the relays incorporated in each of the charging circuit and the discharging circuit while performing based on the consistency between the signals from the second voltage detecting unit and the third voltage detecting unit and the open / close signal for the discharging relay It can be performed by a configuration that makes it possible to determine. The relay state determination is preferably performed based on a mode switching signal. Prior to determining the state of each relay, it is possible to more accurately determine the state of the relay by confirming that both relays are in the open state.

It is a block diagram of the charging device used for charge of the external apparatus controlled by the conventional CPLT signal. It is a block diagram of the control part of the conventional charging device. It is a block diagram of the charging / discharging apparatus of this invention. It is a block diagram of the control part in the charging / discharging apparatus of this invention. It is a flowchart explaining the charge start control in charge mode. It is a flowchart explaining the charge end control in charge mode. It is a flowchart explaining the discharge start control in discharge mode. It is a flowchart explaining the discharge end control in discharge mode.

  Preferred embodiments of the present invention are shown below. The present invention relates to a charging / discharging device having a charging function for charging an external device including a secondary battery from an external power source (system power source) and a discharging function for supplying power from the secondary battery to another general load. However, in the following embodiments, a CPLT signal (a pilot having a duty ratio set in accordance with the magnitude of the rated current) mounted with a large-capacity onboard battery such as EV / PHV is not limited. An example of a vehicle (so-called mode 2 type vehicle) controlled by a signal) will be described.

  As shown in FIG. 3, the charging / discharging device 14 is provided with an external power supply drawing unit 32 that draws the external power supply 15 and a general load outlet 17 to which the general load 16 is connected. The vehicle 1 and the charging / discharging device 14 are connected by a cable including two power supply lines 33, a CPLT signal line 34, and a ground line (not shown). In addition, the charging / discharging device 14 is provided with a display unit (not shown) that displays a charging state and an error. Here, the general load may be a residential distribution board as well as 100V / 200V load equipment used at home and the like. When the general load is a residential distribution board, the feed terminal connected to the distribution board bus can be connected to the charging / discharging device, and the charging / discharging device can be used as a distributed power source. Note that the charge mode and the discharge mode are exclusively controlled.

  The charging / discharging device 14 includes therein a charging electric path 18, a discharging electric path 19, and a control unit 20 that controls charging / discharging.

  The charging circuit 18 connects the external power supply 15 to the vehicle 1 via a cable and supplies power to the vehicle 1 connected to the cable.

  A charging relay 21 is provided in the charging electric circuit 18, and voltage application from the external power source 15 to the power supply port of the vehicle 1 is ON / OFF controlled by opening / closing control from the control unit 20. However, the actual charging start control for the in-vehicle battery is performed by the control circuit 10 on the vehicle side.

  A first voltage detection unit 22 and a second voltage detection unit 23 are disposed on each of the external power supply 15 side and the vehicle 1 side with the charging relay 21 interposed therebetween. In the first voltage detection unit 22, voltage detection on the external power supply 15 side of the charging relay 21 is performed, and in the second voltage detection unit 23, voltage detection on the vehicle side of the charging relay 21 is performed. Among these, the 2nd voltage detection part 23 also has a function which performs the voltage detection by the side of the vehicle of the discharge relay 24 mentioned later, and can also be provided in a discharge electric circuit.

  The discharge circuit 19 connects the vehicle 1 to the general load outlet 17 via a cable and supplies power to the general load 16. The general load 16 may be connected from the general load outlet 17 to the bus feed terminal of the distribution board.

  A discharge relay 24 is provided in the discharge circuit 19, and voltage application from the in-vehicle battery 25 of the vehicle 1 to the general load 16 is ON / OFF controlled by opening / closing control from the control unit 20. However, the actual discharge start control from the in-vehicle battery 25 is performed by the control circuit 10 on the vehicle side.

  The second voltage detection unit 23 is disposed at a position where the potential of the discharge circuit 19 on the vehicle 1 side can be measured across the discharge relay 24, and the third voltage detection unit 26 is disposed on the general load 16 side. Has been placed. The open / close state of the discharge relay 24 is determined by measuring the voltages detected by the second voltage detector 23 and the third voltage detector 26.

  As shown in FIG. 4, in addition to the CPLT circuit 27 that generates the CPLT signal, the control unit 20 includes a determination unit 28 that transmits a charging circuit open / close signal to the relays 21 and 24 based on the CPLT signal, and a voltage detection unit. Contact detection means 29 for detecting the open / closed state of the relays 21 and 24 based on the measurement results (voltage / no voltage) of 22, 23 and 26, a management circuit 30 for generating a charge mode / discharge mode switching signal, A discharge control unit 31 is provided that receives a closing / opening signal from the determination means 28 and transmits the opening / closing signal to the discharge relay 24. In addition, it is also possible to transmit a signal directly from the determination means 28 to the discharge relay 24. In this case, the discharge control unit 31 is unnecessary. Furthermore, the contact detection means 29 may determine the open / closed state of the relays 21, 24 based on the measurement results of the voltage detection units 22, 23, 26 by the determination means 28. Further, the management circuit 30 and the charge control circuit 10 of the vehicle 1 are connected by a signal line 35, and a command signal for charge mode / discharge mode is transmitted from the outside to the management circuit. The management circuit 30 determines the charging mode or discharging mode of the charging / discharging device based on the command signal. Note that the signal line 35 may communicate wirelessly.

  The management circuit 30 receives a command from the outside (for example, the vehicle 1) and generates a charge mode / discharge mode switching signal. The generated switching signal is output to the determination means 28. The generation of the switching signal is performed when the predetermined condition is satisfied (for example, switching to the discharge mode when the general load is connected and switching to the charging mode when the general load is removed). It is also possible to do this. The command signal is not limited to a signal transmitted from a vehicle equipped with a vehicle-mounted battery. For example, when a plurality of charge / discharge devices are installed, the command signal is managed from a central control unit that controls each charge / discharge device. It is also possible to send to.

  The determination unit 28 receives the switching signal from the management circuit 30 and exclusively switches the charging mode / discharging mode. That is, in both the charging mode and the discharging mode, the charging relay 21 and the discharging relay 24 are controlled so as not to be closed at the same time, and the voltage of the external power source of 200V is applied to a general load of 100V. It is avoiding.

  The CPLT circuit 27 generates a CPLT signal corresponding to the connection state of the vehicle 1 and outputs it to the determination means 28 at all times, as in the conventional case. When the vehicle is not connected to the CPLT signal, the potential of the CPLT signal in the charging / discharging device (the potential of the connector connecting portion to the vehicle) is a constant voltage of 12V. When the vehicle 1 is connected, the voltage is divided by the vehicle internal resistance R2 to be adjusted to a constant voltage of 9V. If the charge / discharge device is in a chargeable state (when conditions such as no timer control and no contract current problem are satisfied), the CPLT signal is oscillated to generate 9V oscillation. Subsequently, when the charging / discharging permission switch 12 on the vehicle side is turned on, the voltage shifts to R3 to shift to 6V oscillation. The determination means 28 receives 6V oscillation and outputs a relay closing signal, and receives 9V oscillation and outputs a relay opening signal under any mode of charge mode / discharge mode (hereinafter, mode 2 control). Since the management circuit 30 is set as a charging mode when the vehicle is not connected, charging is started even when the command signal for determining the mode of the management circuit is not received from the vehicle.

  As described above, the determination unit 28 transmits a charging circuit open / close signal to the relay 5 based on the CPLT signal, and also includes a signal indicating the open / close state of the relay from the contact detection units 22, 23, and 26, and the management circuit 30. In response to the mode switching signal, consistency with the relay open / close signal is determined, and the relay state is determined as shown in Table 2 below. Note that the function of the determination means 28 is continuously operating continuously.

  Specifically, first, when the vehicle 1 is connected, the determination unit 28 receives a mode switching signal from the management circuit 30 and switches the charging mode / discharging mode. In the initial setting, the charging mode is selected.

(Charge mode)
As shown in FIG. 5, when the charging mode is selected, first, a state determination for confirming that both relays 21 and 24 are in an open state is performed prior to the state determination of each relay 21 and 24. Here, as shown in the state A of Table 2, the measurement result of the first voltage detection unit 22 is a voltage, and the measurement results of the second and third voltage detection units 23 and 26 are no voltage. It is determined that the charging relay 21 is not welded (state B) and is in a normal state. In addition, the welding (state D) of the discharge relay 24 mentioned later is also judged simultaneously. When the state B or the state D is determined, the CPLT signal is not oscillated, the mode 2 control is stopped, and an abnormal display is made on the display unit.

  If it is determined in the initial state determination that the current state is normal, the charging relay 21 is closed through the mode 2 control. At this time, the discharge relay 24 maintains the open circuit state. After the closing operation of the charging relay 21, the measurement results of the first voltage detection unit 22 and the second voltage detection unit 23 are transmitted to the determination unit 28, and the state determination of the charging relay 21 is performed. Here, as shown in the state C of Table 2, the measurement results of the first voltage detection unit 22 and the second voltage detection unit 23 are in a state where a closing signal is transmitted from the determination unit 28 to the charging relay 21. When both have a voltage, it is determined that the charging relay 21 is not in a non-operating state (state E) due to a failure or the like and the discharge relay 24 is not in a welding state (state D), and is in a normal state. . When the non-operation determination (state E) of the charging relay 21 is made, an opening signal is output from the determination means 28 to the charging relay 21 and an error is displayed on the display unit. When the welding determination (state D) of the discharge relay 24 is made, the discharge relay 24 is immediately opened to avoid voltage application from the external power supply 15 (200 V) to the general load 16 (100 V).

  As shown in FIG. 6, when charging is stopped / expired, the charging control circuit 10 on the vehicle side opens the charging / discharging permission switch 12, and accordingly, the CPLT signal becomes 9V oscillation. An opening signal is output to the charging relay 21 and the charging relay 21 is opened. In the state determination at this time, as shown in the state A of Table 2, the measurement result of the first voltage detection unit 22 is a voltage, and the measurement results of the second and third voltage detection units 26 are no voltage. If the charging relay 21 is not welded (state B), it is determined that the charging relay 21 is in a normal state. In addition, when welding determination is made, an abnormal display is made on the display unit.

(Discharge mode)
The charging / discharging device switches from the charging mode to the discharging mode in response to a command signal from the vehicle. As shown in FIG. 7, when the discharge mode is selected, the state determination of both relays 21 and 24 is started. Here, as shown in the state F of Table 2, when the measurement results of the second and third voltage detectors 23 and 26 are no voltage, it is determined that they are in a normal state. If the vehicle is connected to the charging / discharging device and the charging / discharging device is ready, the 9-V oscillation of the CPLT signal is maintained, but before the discharge relay 24 is closed in the case of switching to the charging mode. When determination other than state F is made, the oscillation of the CPLT signal is stopped and an abnormal display is made on the display unit. When the oscillation of the CPLT signal is stopped, the charging control circuit 10 on the vehicle side cannot close the charging / discharging permission switch 12, and therefore no discharging is performed. Further, since the contact welding determination of the discharge relay 24 can be determined only in the state D, the determination is made in the charging mode, and if the contact welding is determined, an abnormality is displayed, and control is performed so as not to switch to the discharge mode thereafter.

  If it is determined in the state determination before the discharge relay 24 is closed that the normal state is present, the 9-V oscillation is maintained in the CPLT signal, and the charge control circuit 10 is charged / discharged when the vehicle-side discharge preparation is completed. When the permission switch 12 is closed, the CPLT signal becomes 6V oscillation. Upon receiving the 6V oscillation CPLT signal, the determination means 28 outputs a discharge relay closing signal to the discharge control means, and the discharge relay 24 is closed. At this time, the charging relay 21 maintains the open circuit state. After the closing operation of the discharge relay 24, the measurement results of the second voltage detection unit 23 and the third voltage detection unit 26 arranged on each of the vehicle side and the general load side across the discharge relay 24 are sent to the determination unit 28. It is transmitted and the state determination of the discharge relay 24 is performed. Here, as shown in the state G in Table 2, the measurement results of the second voltage detection unit 23 and the third voltage detection unit 26 are transmitted from the determination unit 28 to the discharge relay 24. If there is a voltage on both the vehicle side and the general load side, the discharge relay 24 is not in a non-operating state (state H) due to a failure or the like, and is determined to be in a normal state. . When the non-operation determination (state H) of the discharge relay 24 is made, an error is displayed on the display unit.

  The vehicle stops discharging when the discharge allowable value is exceeded. To stop discharging, the vehicle-side charge control circuit 10 opens the charge / discharge permission switch 12 as shown in FIG. In response to this, the determination means 28 outputs an open circuit signal to the discharge relay 24, and the discharge relay 24 is opened. Here, the open state of the discharge relay 5 is determined. In this state determination, as shown in the state G of Table 1, when the measurement result of the second voltage detection unit 23 is a voltage and the measurement result of the third voltage detection unit 26 is no voltage, the normal state It is determined that In the case other than the state G, an error is displayed on the display unit. In the discharge mode, since there is no voltage on the vehicle battery when the discharge is completed, the welding determination (state D) of the discharge relay 24 is determined under the charge mode (state D in Table 2) as described above.

  In the above embodiment, an example in which one vehicle is connected to one charging / discharging device has been described. However, as another embodiment, a plurality of vehicles can be connected to a plurality of charging / discharging devices. In this case, a command signal enabling switching between the charge mode / discharge mode is sent to the management circuit according to a command from a central control unit that controls each charge / discharge device. Furthermore, the management circuit can be controlled in the charging mode when the vehicle is connected, and can be switched to the discharging mode when the connection of the general load is detected. The connection detection of the general load can be performed, for example, by changing the potential of the capacitor.

  In addition, the power supply to the general load can be stopped by switching to the charging mode, or the charging mode can be switched when the allowable discharge amount of each vehicle is exceeded.

  In the above embodiment, each relay is opened and closed using the CPLT signal. However, if the vehicle side voltage detection unit is configured to use the discharge side and the charge side in common, the relay opening and closing control is applied to the CPLT signal. Regardless, for example, an operation button or the like provided on the charge / discharge device may be used. If the operation buttons of the charging / discharging device are provided for charging and discharging, and the charging mode and discharging mode are controlled exclusively from the charging / discharging device side, the management circuit for switching the mode is also omitted. Can do.

1 Vehicle (external equipment)
2 Charging Device 3 Control Unit 4 CPLT Circuit 5 Relay 6 Determination Unit 7 Voltage Detection Unit 8 Contact Detection Unit 9 Power Supply Unit 10 Charge Control Circuit 11 Oscillator 12 Charging Permission Switch 13 Display Unit 14 Charging / Discharging Device 15 External Power Supply 16 General Load 17 General Load socket 18 Charging electric circuit 19 Discharging electric circuit 20 Control unit 21 Charging relay 22 First voltage detection unit 23 Second voltage detection unit 24 Discharge relay 25 In-vehicle battery 26 Third voltage detection unit 27 CPLT circuit 28 Determination means 29 Contact point Detection unit 30 Management circuit 31 Discharge control means 32 External power supply unit 33 Power supply line 34 CPLT signal line 35 Signal line

Claims (5)

  A charging circuit for charging an external device with a secondary battery from an external power source, a charging relay for opening and closing the charging circuit, a discharging circuit for supplying power to the general load from the secondary battery of the external device, and opening and closing the discharging circuit Discharge relay, a control unit for controlling opening and closing of each relay, a first voltage detection unit provided on the external power supply side of the charging relay, and an external device side of the charging relay and discharging relay, provided in common to each relay A charge / discharge device comprising: a second voltage detection unit; and a third voltage detection unit provided on a general load side of the discharge relay.   The control unit detects an open / close state of each relay based on a detection signal from each voltage detection unit, transmits an open / close signal to each relay, and determines the state of each relay based on consistency with the open / close signal. The charging / discharging device according to claim 1, further comprising a determination unit that performs the operation. The determination means determines the state of the charging relay based on the consistency between the signal indicating the opening / closing state of the charging relay from the first voltage detecting unit and the second voltage detecting unit and the opening / closing signal for the charging relay,
The state determination of the discharge relay is performed based on consistency between a signal indicating an open / close state of the discharge relay from the second voltage detection unit and the third voltage detection unit and an open / close signal for the discharge relay. Item 3. The charge / discharge device according to Item 2.   The control unit includes a management circuit that appropriately generates a mode switching signal in either the charging mode or the discharging mode, and the determination unit performs state determination of each relay based on the mode switching signal. The charge / discharge device according to claim 2.   The charging / discharging device according to claim 4, wherein the determination unit performs relay welding determination in a charging mode among the state determinations of the discharge relay.

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