Abstract: A first line includes a switching element and is electrically coupled to a branch point and an external load which is electrically connectable to a battery parallel-operation circuit. A second line includes a resistive element, and is electrically coupled to the external load and the branch point. The first line and the second line are each provided in a plurality. The plural first lines are connected in parallel to one another, and the plural second lines are connected in parallel to one another. The branch points are electrically coupled respectively to plural external, connectable battery units.

Abstract: There is provided an electricity storage system which comprises an electricity storage device, a charge and discharge switch device which is placed connected to the electricity storage device, a control block which is a charge and discharge control device which controls charging from a power supply and discharging from the electricity storage device to an external load, and an electricity storage device breaker with transmission and reception functions which is provided between the electricity storage device and the charge and discharge switch device, disconnects connection with the electricity storage device according to detection of abnormality of the electricity storage device or according to an instruction of the control block, and notifies the execution of the disconnection to the control block. The control block comprises a hardware disconnection instruction unit in addition to a software disconnection instruction unit.

Abstract: A ground fault detection circuit includes: a first switch circuit that connects/disconnects a first path between a positive bus bar and a ground potential section, the positive bus bar being connected to positive electrodes of secondary battery units through a field-effect transistor including a parasitic diode; a second switch circuit that connects/disconnects a second path between a negative bus bar and a ground potential section, the negative bus bar being connected to negative electrodes of the secondary battery units; and a ground fault detection unit that detects a ground fault of the positive bus bar or the negative bus bar based on an electric current flowing through the first path or the second path.

Abstract: A ground fault detection circuit may include a switch circuit that connects or disconnects a path between a bus bar connected to a secondary battery and a ground potential section; an I/V conversion resistance element for detecting a ground fault of the bus bar based on an electric current flowing through the path; and a resistance element connected in series to the I/V conversion resistance element.

Abstract: There is provided an electricity storage system which comprises an electricity storage device, a charge and discharge switch device which is placed connected to the electricity storage device, a control block which is a charge and discharge control device which controls charging from a power supply and discharging from the electricity storage device to an external load, and an electricity storage device breaker with transmission and reception functions which is provided between the electricity storage device and the charge and discharge switch device, disconnects connection with the electricity storage device according to detection of abnormality of the electricity storage device or according to an instruction of the control block, and notifies the execution of the disconnection to the control block. The control block comprises a hardware disconnection instruction unit in addition to a software disconnection instruction unit.

Abstract: There is provided an electricity storage system which comprises an electricity storage device, a charge and discharge switch device which is placed connected to the electricity storage device, a control block which is a charge and discharge control device which controls charging from a power supply and discharging from the electricity storage device to an external load, and an electricity storage device breaker with transmission and reception functions which is provided between the electricity storage device and the charge and discharge switch device, disconnects connection with the electricity storage device according to detection of abnormality of the electricity storage device or according to an instruction of the control block, and notifies the execution of the disconnection to the control block. The control block comprises a hardware disconnection instruction unit in addition to a software disconnection instruction unit.

Abstract: A secondary battery storage system rack is provided comprising a circuit block which is connected to an electric power line for exchanging electric power with the outside, a secondary battery block which is connected to the circuit block and which has a larger mass than the circuit block, and a storage body unit which stores, in the inside, the circuit block and the secondary battery block, wherein the secondary battery block and the circuit block are placed in one line along a direction of gravitational force, with the secondary battery block placed below the circuit block.

Abstract: There is provided an electricity storage system which comprises an electricity storage device, a charge and discharge switch device which is placed connected to the electricity storage device, a control block which is a charge and discharge control device which controls charging from a power supply and discharging from the electricity storage device to an external load, and an electricity storage device breaker with transmission and reception functions which is provided between the electricity storage device and the charge and discharge switch device, disconnects connection with the electricity storage device according to detection of abnormality of the electricity storage device or according to an instruction of the control block, and notifies the execution of the disconnection to the control block. The control block comprises a hardware disconnection instruction unit in addition to a software disconnection instruction unit.

Abstract: A ground fault detection circuit includes: a first switch circuit that connects/disconnects a first path between a positive bus bar and a ground potential section, the positive bus bar being connected to positive electrodes of secondary battery units through a field-effect transistor including a parasitic diode; a second switch circuit that connects/disconnects a second path between a negative bus bar and a ground potential section, the negative bus bar being connected to negative electrodes of the secondary battery units; and a ground fault detection unit that detects a ground fault of the positive bus bar or the negative bus bar based on an electric current flowing through the first path or the second path.

Abstract: A secondary battery storage system rack is provided comprising a circuit block which is connected to an electric power line for exchanging electric power with the outside, a secondary battery block which is connected to the circuit block and which has a larger mass than the circuit block, and a storage body unit which stores, in the inside, the circuit block and the secondary battery block, wherein the secondary battery block and the circuit block are placed in one line along a direction of gravitational force, with the secondary battery block placed below the circuit block.

Abstract: In a power supply system with a storage battery assembly including storage battery pack groups, when electric power is supplied from at least one of the storage battery pack groups to a load connected to a parallel connection line, the storage battery pack group having the highest output voltage is selected from the storage battery pack groups capable of being commonly connected to the parallel connection line, and is first connected to the parallel connection line, and the highest output voltage of the output voltages of the storage battery pack groups connected to the parallel connection line is set as a reference voltage, and only the storage battery pack groups having an output voltage within a predetermined voltage range during discharging relative to the reference voltage are connected to the parallel connection line.

Abstract: There is provided an electricity storage system which comprises an electricity storage device, a charge and discharge switch device placed to be connected to the electricity storage device, a control block which is a charge and discharge control device which controls charging from a power supply and discharging from the electricity storage device to an external load, an electricity storage device breaker provided between the electricity storage device and the charge and discharge switch device, storage battery state detection units which detect the storage battery state information at a connection point between the electricity storage device and the electricity storage device breaker, and the detection units which detect the state information at a connection point between the electricity storage device breaker and the charge and discharge switch device.

Abstract: A power inverter for use in the system interconnection of a direct-current supply with a commercial alternating-current supply includes an inverter circuit and a filter circuit. Feedback signals affecting the frequency of an output to be produced by the inverter circuit are taken from the filter circuit having frequency response characteristics such that the phase angle is reduced to 0.degree. at three frequencies consisting of a higher frequency, lower frequency and commercial frequency, the last of which lies halfway between the first and second. Under the normal condition, the frequency of the output produced by the inverter circuit is equal to the commercial frequency. In the event of a power failure or power cut in the commercial alternating-current supply system, deviation from the commercial frequency is caused by the characteristics of the filter circuit.