Power supply method for battery pack control circuit of power storage device, and power storage device

Abstract

The objective of the present invention is to supply operating electric power to a battery assembly control circuit in a satisfactory state, from both an electric power converting device and a battery module.　This electricity storage device is provided with a battery module (1) including battery cells (11) and a battery assembly control circuit (12), and an electric power converting device (2) which charges the battery module (1) using commercial electric power and supplies electric power to a load (8), wherein: if the output voltage of the electric power converting device (2) is higher than a set voltage, operating electric power is supplied to the battery assembly control circuit (12) from the electric power converting device (2); the start of the supply of electric power from the electric power converting device (2) to the battery assembly control circuit (12) is detected; operating electric power from the battery module (1) to the battery assembly control circuit (12) starts; and when the battery module (1) is in a discharge stopped state, the supply of electric power from the battery module (1) to the battery assembly control circuit (12) stops.

Description

[Technical field]

[0001] The present invention relates to a power supply system for an assembled battery control circuit of a power storage device including a power conversion device that charges a battery module and a battery module, and to the power storage device. [Background technology]

[0002] An energy storage device including a battery module has been developed (see Patent Document 1). The battery module is provided with a battery control circuit, and a battery module has also been developed in which the power supply circuit of this control circuit is a DC / DC converter that steps down the battery voltage of the battery module, and the battery module supplies operating power from the battery of the battery module. This battery module has the disadvantage that the battery consumes power to operate the control circuit. Even when the battery module is not in use, i.e., not being discharged, the control circuit operates at a predetermined time interval to detect the remaining capacity, and therefore consumes power in this state. Therefore, since this power supply circuit supplies operating power to the control circuit from the battery, the disadvantage of overdischarging occurs due to discharge caused by the dark current of the control circuit, and further, when the battery voltage of the battery module drops, the voltage supplied to the control circuit drops, making it impossible to maintain a normal operating state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-065518 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention was developed with the further objective of eliminating the above-mentioned drawbacks, and one of the objects of the present invention is to provide technology that can stably supply operating power to a battery control circuit from both commercial power and a battery module. [Means for solving the problem]

[0005] A power supply system for a battery pack control circuit of a power storage device according to an embodiment of the present invention is a power supply system for a battery pack control circuit in a power storage device that includes a battery module including a plurality of chargeable battery cells and a battery pack control circuit, and a power conversion device that charges the battery module with commercial power and supplies the commercial power to a load, the power conversion device comprising: For battery modules When the output voltage is higher than a set voltage, operating power is supplied from the power conversion device to the battery pack control circuit of the battery module, and operating power from the battery module to the battery pack control circuit is started in response to a connection signal from a connection detection unit that detects the state in which power supply from the power conversion device to the battery pack control circuit has started, and the power supply from the battery module to the battery pack control circuit is stopped in response to a stop signal from a discharge stop determination unit that detects the discharge stop state of the battery module.

[0006] A power storage device according to an embodiment of the present invention includes a power conversion device that receives power from a commercial power source and supplies the power to a load, a battery module including a plurality of chargeable battery cells and an assembled battery control circuit, a switching circuit that switches the supply of power from the power conversion device and the battery module to the assembled battery control circuit, a connection detection unit that detects the supply of power from the power conversion device to the assembled battery control circuit, and a discharge stop determination unit that determines the discharge stop state of the battery module. For battery modules When the output voltage is higher than a set voltage, power is supplied from the power conversion device to the battery pack control circuit, and when the power supply from the power conversion device to the battery pack control circuit is detected, a connection signal from the connection detection unit is received to supply operating power from the battery module to the battery pack control circuit, and a discharge stop signal from the discharge stop determination unit is received to stop the power supply from the battery module to the battery pack control circuit.

[0007] A power storage device according to another aspect of the present invention includes a power conversion device that receives power from a commercial power source and supplies the power to a load, a battery module including a plurality of chargeable battery cells and a battery pack control circuit, a DC / DC converter that supplies operating power to the battery pack control circuit, a switching circuit that switches the connection between the power conversion device and the battery module, a connection detection unit that detects the power supply from the power conversion device to the battery pack control circuit, and a discharge stop determination unit that determines the discharge stop state of the battery module. For battery modules When the output voltage is higher than a set voltage, the power conversion device is connected to the DC / DC converter, and a connection signal from a connection detection unit that detects the connection between the power conversion device and the DC / DC converter connects the battery module to the DC / DC converter, and a discharge stop signal from the discharge stop determination unit cuts off the connection between the battery module and the DC / DC converter. Effect of the Invention

[0008] The power supply method for the battery pack control circuit of the power storage device and the power storage device described above have the advantage that operating power can be stably supplied to the battery pack control circuit from both the power conversion device and the battery module. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram of a power storage device according to an embodiment of the present invention; [Diagram 2] 2 is a block diagram of a switching circuit of the power storage device shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper", "lower", and other terms including these terms) are used as necessary, but the use of these terms is for the purpose of facilitating understanding of the invention with reference to the drawings, and the meanings of these terms do not limit the technical scope of the present invention. In addition, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or members. Furthermore, the embodiments shown below are specific examples of the technical ideas of the present invention, and do not limit the present invention to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present invention. Furthermore, the contents described in one embodiment or example can be applied to other embodiments or examples. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated to clarify the explanation.

[0011] The power supply system for the battery pack control circuit in the power storage device according to the first embodiment of the present invention is a power supply system for the battery pack control circuit in the power storage device that includes a battery module including a plurality of chargeable battery cells and a battery pack control circuit, and a power conversion device that charges the battery module with commercial power and supplies the commercial power to a load, the power conversion device being For battery modules When the output voltage is higher than a set voltage, operating power is supplied from the power conversion device to the battery pack control circuit of the battery module, and operating power from the battery module to the battery pack control circuit is started in response to a connection signal from a connection detection unit that detects the state in which power supply from the power conversion device to the battery pack control circuit has started, and the power supply from the battery module to the battery pack control circuit is stopped in response to a stop signal from a discharge stop determination unit that detects the discharge stop state of the battery module.

[0012] The power supply method for the battery pack control circuit in the power storage device supplies operating power to the battery pack control circuit from both the power conversion device and the battery module, so that operating power can be supplied in an ideal state without providing a dedicated power source for the battery pack control circuit. The battery pack control circuit monitors the state of each battery cell, so it is maintained in an operating mode and consumes power even when the battery module is not in use, i.e., not being discharged. The battery pack control circuit includes many battery cells to increase the charging / discharging capacity and output. In this battery pack control circuit, the power consumption of the battery pack control circuit increases in order to manage the many battery cells, and in conventional battery pack control devices, a dedicated power source is provided for the battery pack control circuit to supply power. This battery pack control device requires a dedicated power source, which increases the equipment cost. This problem can be solved by adjusting the output voltage of the power conversion device and the battery module themselves with a DC / DC converter and supplying it to the battery pack control circuit. A power storage device that supplies power from a power conversion device to a battery pack control circuit can adjust the voltage of the power conversion device's output using a DC / DC converter and supply it to the battery pack control circuit, but the power conversion device is not always in a state where it outputs a voltage, and cannot supply operating power to the battery pack control circuit when no voltage is being output. The power conversion device outputs voltage when the battery module is being charged and when power is being supplied to the load, but does not output voltage when the battery module is not being charged and power is not being supplied to the load. It is also possible to adjust the output voltage of the battery module to supply operating power to the battery pack control circuit, but this power storage device cannot supply operating power to the battery pack control circuit when the voltage of the battery module drops to the minimum voltage. In addition, a device that supplies operating power from the battery module to the battery pack control circuit has the disadvantage that the battery module always consumes power and the voltage gradually drops.

[0013] The power supply method for the battery pack control circuit in the power storage device supplies operating power to the battery pack control circuit from both the power conversion device and the battery module, and supplies operating power from the power conversion device to the battery pack control circuit when the output voltage of the power conversion device is higher than a set voltage. Furthermore, when a connection detection unit detects that operating power is being supplied from the power conversion device to the battery pack control circuit, operating power is also supplied from the battery module to the battery pack control circuit, and operating power is supplied from both the power conversion device and the battery module to the battery pack control circuit. In this state, if the voltage of the battery module drops, for example, and the battery pack control circuit is over-discharged, the discharge stop determination unit detects this and stops the power supply from the battery module. Therefore, the battery module is not over-discharged, and power can be supplied to the battery pack control circuit. Furthermore, when the battery module is over-discharged, power is supplied from the power conversion device to the battery pack control circuit, and the battery pack control circuit can be maintained in an operating state. When the voltage of the battery module drops, the power conversion device outputs a predetermined voltage to charge the battery module, so that in this state, the output from the power conversion device can supply operating power to the battery pack control circuit. Therefore, the power supply system for the battery pack control circuit in the power storage device described above can supply operating power in an ideal state from both the power conversion device and the battery module.

[0014] The power storage device according to the second embodiment of the present invention includes a power conversion device that receives power from a commercial power source and supplies the power to a load, a battery module including a plurality of chargeable battery cells and a battery pack control circuit, a switching circuit that switches the supply of power from the power conversion device and the battery module to the battery pack control circuit, a connection detection unit that detects the power supply from the power conversion device to the battery pack control circuit, and a discharge stop determination unit that determines the discharge stop state of the battery module. For battery modules When the output voltage is higher than a set voltage, power is supplied from the power conversion device to the battery pack control circuit, and when the power supply from the power conversion device to the battery pack control circuit is detected, a connection signal from the connection detection unit is received to supply operating power from the battery module to the battery pack control circuit, and a discharge stop signal from the discharge stop determination unit is received to stop the power supply from the battery module to the battery pack control circuit.

[0015] The above-mentioned power storage device supplies operating power to the assembled battery control circuit from both the power conversion device and the battery module, and also supplies operating power from the power conversion device to the assembled battery control circuit when the output voltage of the power conversion device is higher than a set voltage. Furthermore, when a connection detection unit detects that operating power is being supplied from the power conversion device to the assembled battery control circuit, the battery module also supplies operating power to the assembled battery control circuit, and supplies operating power from both the power conversion device and the battery module to the assembled battery control circuit. In this state, if the voltage of the battery module drops, etc., and the assembled battery control circuit is in an over-discharge state, the discharge stop determination unit detects this and stops the power supply from the battery module. Therefore, the battery module does not over-discharge, and the battery module can also supply power to the assembled battery control circuit. Furthermore, when the battery module does not supply power to the assembled battery control circuit, the power conversion device supplies power to the assembled battery control circuit, and the assembled battery control circuit can be maintained in an operating state. When the voltage of the battery module drops, the power conversion device outputs a predetermined voltage to charge the battery module, so that in this state, the output from the power conversion device can supply operating power to the assembled battery control circuit. Therefore, the above-described power storage device can supply operating power in an ideal state from both the power conversion device and the battery module.

[0016] A power supply device according to a third embodiment of the present invention includes a power conversion device that receives power from a commercial power source and supplies the power to a load, a battery module including a plurality of chargeable battery cells and an assembled battery control circuit, a DC / DC converter that supplies operating power to the assembled battery control circuit, a switching circuit that switches the connection between the power conversion device and the battery module, a connection detection unit that detects the power supply from the power conversion device to the assembled battery control circuit, and a discharge stop determination unit that determines the discharge stop state of the battery module. For battery modules When the output voltage is higher than a set voltage, the power conversion device is connected to the DC / DC converter, and a connection signal from a connection detection unit that detects the connection between the power conversion device and the DC / DC converter connects the battery module to the DC / DC converter, and a discharge stop signal from the discharge stop determination unit cuts off the connection between the battery module and the DC / DC converter.

[0017] In a fourth embodiment of the present invention, a power storage device includes a switching circuit including a first power switch connected between a power conversion device and a DC / DC converter, and a first input circuit for controlling the first power switch to be turned on and off by comparing the output voltage of the power conversion device with a set voltage. The first input circuit turns the first power switch on when the output voltage of the power conversion device is higher than the set voltage to supply power from the power conversion device to the DC / DC converter, and turns the first power switch off when the output voltage of the power conversion device is lower than the set voltage to cut off the power supply from the power conversion device to the DC / DC converter.

[0018] In a fifth embodiment of the present invention, a first input circuit includes a first control switch that is controlled to be turned on and off by an output voltage of a power conversion device and switches a first power switch on and off.

[0019] In a sixth embodiment of the energy storage device of the present invention, the first control switch and the first power switch are FETs, and the FET of the first control switch controls the first power switch to control the power supply from the power conversion device to the DC / DC converter.

[0020] A seventh embodiment of the present invention provides an energy storage device including a switching circuit having a second power switch connected between a battery module and a DC / DC converter, and a second input circuit that controls the second power switch to be turned on and off by a connection signal from a connection detection unit.

[0021] In a power storage device according to an eighth embodiment of the present invention, the second input circuit includes a second control switch that is switched by a connection signal from the connection detector to control the second power switch to be on or off.

[0022] A ninth embodiment of the present invention provides an energy storage device including a switching circuit having a second power switch connected between a battery module and a DC / DC converter, and a second input circuit that controls the second power switch to be turned off in response to a discharge stop signal from a discharge stop determination unit.

[0023] In a power storage device according to a tenth embodiment of the present invention, the second input circuit includes a second control switch that is switched by a discharge stop signal from the discharge stop determination unit and controls the second power switch to be turned off.

[0024] In an energy storage device of an eleventh embodiment of the present invention, the second power switch and the second control switch are FETs, and the FET of the second control switch controls the second power switch to control the power supply from the battery module to the DC / DC converter.

[0025] In the energy storage device of the twelfth embodiment of the present invention, a reverse current prevention diode is connected between the output side of the power conversion device and the DC / DC converter, and a reverse current prevention diode is also connected between the output side of the battery module and the DC / DC converter.

[0026] In a power storage device according to a thirteenth embodiment of the present invention, a power conversion device includes a converter that charges a battery module with commercial power, and a DC / AC inverter that supplies the power of the battery module to a load.

[0027] (Embodiment 1) The energy storage device 100 in FIG. 1 includes a power conversion device 2 that receives power from a commercial power source 9 and supplies power to a load 8, a battery module 1 that has a plurality of chargeable battery cells 11 and an assembled battery control circuit 12, a switching circuit 3 that switches the supply of power from the power conversion device 2 and the battery module 1 to the assembled battery control circuit 12, a connection detection unit 5 that detects the state in which power is being supplied from the power conversion device 2 to the assembled battery control circuit 12 and outputs a connection signal, and a discharge stop determination unit 6 that detects when the discharging battery module 1 has entered a discharge stop state and outputs a discharge stop signal.

[0028] (Battery module 1) The battery module 1 comprises an assembled battery 10 in which multiple rechargeable battery cells 11 are connected, and an assembled battery control circuit 12 that is connected to the assembled battery 10 and controls the charging and discharging of the assembled battery 10. The present invention does not specify the circuit configuration of the assembled battery control circuit 12, but the assembled battery control circuit 12 comprises, for example, protection circuits such as circuits that detect the voltage and remaining capacity of the assembled battery 10 and battery cells 11, or circuits that equalize the voltage and remaining capacity of the battery cells 11 and assembled battery 10, and a charge and discharge control circuit.

[0029] (Power conversion device 2) The power conversion device 2 supplies power supplied from a commercial power source 9 to the battery module 1 for charging. In the power storage device 100, when the load 8 is in an operating state while no commercial power is being supplied, power is supplied from the battery module 1 to the load 8. The power conversion device 2 includes a converter 21 that converts commercial power to a charging voltage for the battery module 1, and a DC / AC inverter 22 that converts a direct current output from the battery module 1 into an alternating current voltage to be supplied to the load 8. The load 8 is connected to the output side of the DC / AC inverter 22. The power conversion device 2 is provided with a bus line 23 that supplies the commercial power source 9 directly to the load 8, and supplies power to the load 8 via the bus line 23 when commercial power is being supplied.

[0030] The power supply circuit of the battery pack control circuit 12 is connected to the power conversion device 2 and the battery module 1 via a DC / DC converter 4 and a switching circuit 3, and DC operating power is supplied from either or both of the power conversion device 2 and the battery module 1 via the DC / DC converter 4. The DC / DC converter 4 converts a high voltage, for example, 400V to 600V, of the power conversion device 2 or the battery module 1 into a power supply voltage of the battery pack control circuit 12, for example, a DC voltage of 24V to 5V, and outputs it.

[0031] (switching circuit 3) The switching circuit 3 switches the state in which operating power is supplied to the assembled battery control circuit 12 from either or both of the power conversion device 2 and the battery module 1 via the DC / DC converter 4. The switching circuit 3 supplies operating power from the power conversion device 2 to the assembled battery control circuit 12 when the output voltage of the power conversion device 2 is higher than a set voltage. When operating power is supplied from the power conversion device 2, the assembled battery control circuit 12 starts up, and a connection detection unit 5 detects a state in which the power conversion device 2 starts supplying power to the assembled battery control circuit 12. When the connection detection unit 5 detects the start of power supply from the power conversion device 2, it outputs a connection signal to the switching circuit 3. When a connection signal is input from the connection detection unit 5 to the switching circuit 3, the switching circuit 3 starts supplying operating power from the battery module 1 to the assembled battery control circuit 12. When power is supplied from the battery module 1 to the assembled battery control circuit 12, the battery module 1 is discharged, and the discharge stop determination unit 6 detects a discharge stop state of the battery module 1, and the discharge stop determination unit 6 outputs a discharge stop signal to the switching circuit 3. In this state, the switching circuit 3 stops the power supply from the battery module 1 to the battery pack control circuit 12. The discharge stop determination unit 6 stores conditions for stopping the discharge of the battery module 1, and when the battery module 1 enters this state, it outputs a discharge stop signal to the switching circuit 3, causing the switching circuit 3 to stop the power supply from the battery module 1 to the battery pack control circuit 12.

[0032] The switching circuit 3 shown in Fig. 2 switches the connection between the DC / DC converter 4 and the power conversion device 2 and the battery module 1 to control the power supply from the power conversion device 2 to the battery pack control circuit 12 and the power supply from the battery module 1 to the battery pack control circuit 12. The switching circuit 3 in Fig. 2 controls the power supply from the power conversion device 2 to the DC / DC converter 4 with a first power switch 31. The first power switch 31 is controlled to be turned on and off by a first input circuit 32. The first input circuit 32 compares the output voltage of the power conversion device 2 with a set voltage and controls the first power switch 31 to be turned on and off.

[0033] (First power switch 31) The first power switch 31 is an n-channel power MOSFET, and is connected between the negative output terminal of the power conversion device 2 and the DC / DC converter 4. A reverse current prevention diode 33 is connected in series to the first power switch 31, and the negative side of the power conversion device 2 is connected to the DC / DC converter 4 via a series circuit of the first power switch 31 and the reverse current prevention diode 33. The first power switch 31 is controlled to be turned on and off by a first input circuit 32, and in the on state, it supplies power from the power conversion device 2 to the DC / DC converter 4, and supplies operating power from the DC / DC converter 4 to the assembled battery control circuit 12. In the off state, the first power switch 31 cuts off the power supply to the DC / DC converter 4, and stops the power supply from the power conversion device 2 to the assembled battery control circuit 12.

[0034] (First input circuit 32) The first input circuit 32 turns the first power switch 31 on when the output voltage of the power conversion device 2 is higher than a set voltage, supplies power from the power conversion device 2 to the DC / DC converter 4, and supplies operating power from the power conversion device 2 to the assembled battery control circuit 12, and switches the first power switch 31 off when the output voltage of the power conversion device 2 is lower than the set voltage, cutting off the power supply from the power conversion device 2 to the DC / DC converter 4, i.e., the power supply to the assembled battery control circuit 12. The set voltage is set lower than the output voltage of the power conversion device 2 when commercial power is supplied. When the output voltage of the power conversion device 2 is higher than the set voltage, the device is connected to commercial power, and in this state, operating power is supplied from the power conversion device 2 to the assembled battery control circuit 12.

[0035] The first input circuit 32 includes a first control switch 34 that turns on and off the first power switch 31. The first control switch 34 is controlled to turn on and off by the output voltage of the power conversion device 2 to switch the first power switch 31 to turn on and off. The first control switch 34 is an n-channel FET, and turns on and off the first power switch 31 by turning on and off the first control FET 34A. The first control FET 34A switches the first power switch 31 to the on state in the on state and sets the first power switch 31 to the off state in the off state.

[0036] The first control FET 34A, which is the first control switch 34, has its gate connected to the output side of the power conversion device 2 via the first input resistor 35 and is controlled to turn on and off by the output voltage of the power conversion device 2. The first control FET 34A has its drain connected to the positive-side output of the power conversion device 2 via the second input resistor 36 and its source connected to the ground line 39 via the second input resistor 36. The first control FET 34A is switched to turn on and off by the voltage input to the gate from the first input resistor 35. These first input resistors 35, 35 are voltage-dividing resistors that divide the output voltage of the power conversion device 2 and input it to the gate of the first control FET 34A. The first input resistors 35, 35, which are voltage-dividing resistors, divide the output voltage of the power conversion device 2 at a specific ratio and input it to the gate of the first control FET 34A. The electrical resistance of the voltage-dividing resistors divides the output voltage of the power conversion device 2 to which commercial power is supplied, inputs it to the gate of the first control FET 34A, turns on the first control FET 34A, and is set to a resistance value that turns off the first control FET 34A with the output voltage in a state where commercial power is not supplied to the power conversion device 2.

[0037] The first power FET 31A, which is a MOSFET of the first power switch 31, is switched to an on state when the first control FET 34A is on. The gate of the first power FET 31A is connected to the drain of the first control FET 34A, and the drain voltage of the first control FET 34A is input. The first power FET 31A is switched on and off by a voltage input from the drain of the first control FET 34A to the gate. When the first control FET 34A is on, the second input resistors 36, 36 connected in series become voltage dividing resistors, which divide the output voltage of the power conversion device 2 and input it to the gate of the first power FET 31A. The second input resistors 36, 36, which are voltage dividing resistors, divide the output voltage of the power conversion device 2 at a specific ratio and input it to the gate of the first power FET 31A. The electric resistance of the voltage dividing resistor is set to a resistance value that divides the output voltage of the power conversion device 2 to which commercial power is supplied, inputs the divided voltage to the gate of the first power FET 31A, and sets the first power FET 31A to an ON state. Therefore, when the first control FET 34A is in an ON state, the gate voltage (VGS) of the first power FET 31A becomes an ON voltage, and when the first control FET 34A is in an OFF state, the voltage input to the gate of the first power FET 31A becomes equal to or lower than the cutoff voltage, and sets the gate voltage (VGS) to an OFF voltage. When the first power FET 31A is in an ON state, it supplies power from the power conversion device 2 to the DC / DC converter 4, and when it is in an OFF state, it cuts off the power supply from the power conversion device 2 to the DC / DC converter 4.

[0038] (Connection detection unit 5) The connection detection unit 5 detects a state in which power is supplied from the power conversion device 2 to the assembled battery control circuit 12, and outputs a connection signal to the switching circuit 3. The switching circuit 3 detects the connection signal input from the connection detection unit 5, and supplies power from the battery module 1 to the assembled battery control circuit 12. For example, the connection detection unit 5 detects that operating power is supplied from the power conversion device 2 to the assembled battery control circuit 12 and the assembled battery control circuit 12 is activated, and detects that power supply from the power conversion device 2 to the assembled battery control circuit 12 has started, and outputs a connection signal. At this time, the connection detection unit 5 outputs a connection signal when the battery module 1 is in a dischargeable state. However, the connection detection unit 5 can also output a connection signal by detecting the ON state of the first control switch 34 or the first power switch 31 of the first input circuit 32. Alternatively, the connection detection unit 5 can detect that power supply from the power conversion device 2 to the assembled battery control circuit 12 via the DC / DC converter 4 has started in any case. hand For example, the output current supplied from the power conversion device 2 to the DC / DC converter 4 can be detected and a connection signal can be output. The switching circuit 3 can be provided as a dedicated circuit, but is preferably built into the battery pack control circuit 12.

[0039] (Discharge stop determination section 6) The discharge stop determination unit 6 detects a state in which discharging from the battery module 1 is stopped, and outputs a discharge stop signal to the switching circuit 3. For example, the discharge stop determination unit 6 detects the voltage and remaining capacity of the battery module 1 to be discharged, and determines whether to permit or stop discharging the battery module 1 in order to prevent over-discharging of the battery, and outputs a discharge stop signal when the battery module 1 is in a state in which discharging is stopped. The discharge stop determination unit 6 preferably detects the voltage and remaining capacity of the battery module 1 and outputs a discharge stop signal, but can also detect all other parameters that stop discharging the battery module 1, such as the battery temperature, and output a discharge stop signal. The discharge stop determination unit 6 can be built into the assembled battery control circuit 12, or can be provided separately from the assembled battery control circuit 12 as a dedicated circuit configuration.

[0040] (Second input circuit 42) 2 controls the power supply from the battery module 1 to the DC / DC converter 4 with the second power switch 41. The second power switch 41 is controlled to be turned on and off by the second input circuit 42. The second input circuit 42 starts the power supply from the battery module 1 to the assembled battery control circuit 12 with a connection signal input from the connection detection unit 5, and stops the power supply from the battery module 1 to the assembled battery control circuit 12 with a discharge stop signal input from the discharge stop determination unit 6. The switching circuit 3 turns the second power switch 41 on with the connection signal input from the connection detection unit 5 to supply power from the battery module 1 to the DC / DC converter 4 and supply operating power from the battery module 1 to the assembled battery control circuit 12, but when a discharge stop signal for the battery module 1 is input from the discharge stop determination unit 6, the switching circuit 3 switches the second power switch 41 off to cut off the power supply from the battery module 1 to the DC / DC converter 4, i.e., the power supply to the assembled battery control circuit 12. The discharge stop determination unit 6 detects the voltage and remaining capacity of the battery module 1 to prevent the battery module 1 from over-discharging, and detects a discharge stop signal.

[0041] The second input circuit 42 includes a second control switch 44 and a second power switch 41 that is controlled to be turned on and off by the second control switch 44. The second control switch 44 is controlled by a connection signal input from the connection detection unit 5. The second power switch 41 is controlled to be turned on and off by the second control switch 44. The second control switch 44 and the second power switch 41 are n-channel FETs, and the second power switch 41 is a power MOSFET. The second control switch 44 switches the second power switch 41 to the on state in the on state, and switches the second power switch 41 to the off state in the off state.

[0042] The second control FET 44A, which is the second control switch 44, has its gate connected to the connection detection unit 5, its drain connected to the positive output of the battery module 1 via the fourth input resistor 46, and its source connected to the ground line 49 via the fourth input resistor 46. The second control FET 44A is controlled to be turned on and off by a connection signal input to its gate from the connection detection unit 5. The second control FET 44A has its gate connected to the output terminal of the battery module 1 via the third input resistor 45, which is a voltage dividing resistor that divides the output voltage of the battery module 1 and inputs it to the gate of the second control FET 44A. The third input resistor 45, which is a voltage dividing resistor, controls the second power FET 41A, which is the second power switch 41, via the second control FET 44A within the normal voltage range of the battery module 1, but the resistance value of the voltage dividing resistor is set to a resistance value that does not turn the second control FET 44A on when the output voltage of the battery module 1 is within a specified range. The second input circuit 42 turns the second control FET 44A to an on state when a connection signal is input from the connection detector 5 to the gate of the second control FET 44A.

[0043] (Second power switch 41) The second power FET 41A, which is a MOSFET of the second power switch 41, is switched to the ON state when the second control FET 44A is in the OFF state. The gate of the second power FET 41A is connected to the drain of the second control FET 44A, and the drain voltage of the second control FET 44A is input. The second power FET 41A is switched ON and OFF by the voltage input from the drain of the second control FET 44A to the gate. When the second control FET 44A is in the ON state, the fourth input resistors 46, 46 connected in series become voltage dividing resistors, which divide the output voltage of the battery module 1 and input it to the gate of the second power FET 41A. The fourth input resistors 46, 46, which are voltage dividing resistors, divide the output voltage of the battery module 1 at a specific ratio and input it to the gate of the second power FET 41A. The electrical resistance of the voltage dividing resistor is set to a resistance value that divides the output voltage of the battery module 1 and inputs the divided voltage to the gate of the second power FET 41A to turn the second power FET 41A on. Therefore, when the second control FET 44A is in the on state, the gate voltage (VGS) of the second power FET 41A becomes the on voltage, and when the second control FET 44A is in the off state, the voltage input to the gate of the second power FET 41A becomes equal to or lower than the cutoff voltage, and the gate voltage (VGS) becomes the off voltage. When the second power FET 41A is in the on state, it supplies power from the battery module 1 to the DC / DC converter 4, and when it is in the off state, it cuts off the power supply from the battery module 1 to the DC / DC converter 4.

[0044] When the second control FET 44A is in the on state, the second power FET 41A is in the on state, so the connection detection unit 5 inputs a “High” level connection signal to the gate of the second control FET 44A to turn the second control FET 44A on and turn the second power FET 41A on. Furthermore, the discharge stop determination unit 6 inputs a “Low” level discharge stop signal to the gate of the second control FET 44A to turn the second control FET 44A off and turn the second power FET 41A off, so the discharge stop determination unit 6 inputs a “Low” level discharge stop signal to the gate of the second control FET 44A to turn the second control FET 44A off, and with the second control FET 44A in the off state, the second power FET 41A is turned off, and the power supply from the battery module 1 to the battery pack control circuit 12 is stopped.

[0045] 2 has a reverse current prevention diode 33 connected between the output side of the power conversion device 2 and the DC / DC converter 4, and also has a reverse current prevention diode 43 connected between the output side of the battery module 1 and the DC / DC converter 4. The reverse current prevention diodes 33, 43 are connected in a direction that allows power to be supplied from the power conversion device 2 to the DC / DC converter 4 side and from the battery module 1 to the DC / DC converter 4 side, thereby preventing power supply from the DC / DC converter 4 to the power conversion device 2 or the battery module 1. [Industrial Applicability]

[0046] The present invention can be suitably used in various power storage devices as a power supply system and power storage device that can stably supply operating power to a battery control circuit from both commercial power and a battery module. [Explanation of symbols]

[0047] 100...Electricity storage device 1. Battery module 2. Power conversion device 3...Switching circuit 4. DC / DC converter 5…Connection detection section 6...Discharge stop judgment section 8... Load 9... Commercial power supply 10... Battery pack 11... Battery cell 12... Battery pack control circuit 21... Converter 22... DC / AC inverter 23... Bus line 31... First power switch 31A... First power FET 32... First input circuit 33... Reverse current prevention diode 34... First control switch 34A... First control FET 35... First input resistor 36... Second input resistor 39... Ground line 41... Second power switch 41A... Second power FET 42... Second input circuit 43... Reverse current prevention diode 44... Second control switch 44A... Second control FET 45... Third input resistor 46... Fourth input resistor 49... Ground line

Claims

1. A battery module including a plurality of rechargeable battery cells and a battery pack control circuit; a power conversion device that charges the battery module with commercial power and supplies the commercial power to a load; A power supply method for a battery pack control circuit in a power storage device, comprising: In a state where the output voltage of the power conversion device for the battery module is higher than a set voltage, supplying operating power from the power conversion device to a battery pack control circuit of the battery module; a connection signal from a connection detection unit that detects a state in which power supply from the power conversion device to a battery pack control circuit has started, Initiating operation power from the battery module to a battery pack control circuit; A stop signal from a discharge stop determination unit that detects a discharge stop state of the battery module, A power supply system for an assembled battery control circuit of an electricity storage device, comprising: stopping power supply from the battery module to the assembled battery control circuit.

2. a power conversion device that receives power from a commercial power source and supplies the power to a load; A battery module including a plurality of rechargeable battery cells and a battery pack control circuit; From the power conversion device and the battery module, a switching circuit that switches the supply of power from a power source to the battery pack control circuit; a connection detection unit that detects a power supply from the power conversion device to the battery pack control circuit; a discharge stop determination unit for determining whether the battery module is in a discharge stop state; The switching circuit includes: In a state where the output voltage of the power conversion device for the battery module is higher than a set voltage, supplying power from the power conversion device to the battery pack control circuit; In a state where power supply from the power conversion device to the battery pack control circuit is detected, A connection signal from the connection detection unit, supplying operating power from the battery module to the battery pack control circuit; A discharge stop signal from the discharge stop determination unit, The power storage device further comprises: a power supply control circuit for stopping power supply from the battery module to the battery pack control circuit.

3. a power conversion device that receives power from a commercial power source and supplies the power to a load; A battery module including a plurality of rechargeable battery cells and a battery pack control circuit; a DC / DC converter for supplying operating power to the battery pack control circuit; A switching circuit that switches a connection between the power conversion device and the battery module; a connection detection unit that detects a power supply from the power conversion device to the battery pack control circuit; a discharge stop determination unit for determining whether the battery module is in a discharge stop state; The switching circuit includes: In a state where the output voltage of the power conversion device for the battery module is higher than a set voltage, The power conversion device is connected to the DC / DC converter; A connection signal from the connection detection unit that detects a connection between the power conversion device and the DC / DC converter, connecting the battery module to the DC / DC converter; A discharge stop signal from the discharge stop determination unit, A power storage device comprising: a power storage unit that cuts off a connection between the battery module and the DC / DC converter.

4. The electricity storage device according to claim 3, The switching circuit, a first power switch connected between the power conversion device and the DC / DC converter; Comparing the output voltage of the power conversion device with a set voltage, a first input circuit for controlling the first power switch to be turned on and off; The first input circuit is The first power switch is turned on in a state in which the output voltage of the power conversion device is higher than a set voltage, supplying power from the power conversion device to the DC / DC converter; Switching the first power switch to an off state in a state in which the output voltage of the power conversion device is lower than a set voltage, A power storage device, characterized in that the power supply from the power conversion device to the DC / DC converter is cut off.

5. The electricity storage device according to claim 4, The first input circuit, The power converter is turned on and off by an output voltage of the power converter. A power storage device comprising: a first control switch that switches the first power switch on and off.

6. The electricity storage device according to claim 5, the first control switch and the first power switch are FETs; The FET of the first control switch controls the first power switch, A power storage device, characterized in that the power supply from the power conversion device to the DC / DC converter is controlled.

7. The electricity storage device according to claim 3, The switching circuit, a second power switch connected between the battery module and the DC / DC converter; A connection signal from the connection detection unit, and a second input circuit that controls the second power switch to be turned on and off.

8. The electricity storage device according to claim 7, The second input circuit, Switched by a connection signal from the connection detection unit, A power storage device comprising: a second control switch for controlling the second power switch to be turned on and off.

9. The electricity storage device according to claim 3, The switching circuit, a second power switch connected between the battery module and the DC / DC converter; A discharge stop signal from the discharge stop determination unit, and a second input circuit that controls the second power switch to be turned off.

10. The power storage device according to claim 9, The second input circuit, The discharge stop determination unit switches the discharge stop signal. A power storage device comprising: a second control switch that controls the second power switch to be turned off.

11. The electricity storage device according to claim 8 or 10, the second power switch and the second control switch are FETs; The FET of the second control switch controls the second power switch, The power storage device is characterized by controlling the power supply from the battery module to the DC / DC converter.

12. The power storage device according to any one of claims 3 to 11, Between the output side of the power conversion device and the DC / DC converter, A reverse current prevention diode is connected, and Between the output side of the battery module and the DC / DC converter, 1. A power storage device comprising a reverse current prevention diode connected thereto.

13. The power storage device according to any one of claims 2 to 11, The power conversion device, A converter that charges the battery module with commercial power; a DC / AC inverter that supplies power from the battery module to a load.

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