Abstract: A power storage device according to an aspect of the present disclosure includes: a casing including a bottom wall and a top wall opposite to the bottom wall; a storage battery; an electrical unit; and a cooling unit. The storage battery is disposed in the casing and separated from the bottom wall. The electrical unit is disposed in the casing and located closer to the top wall than the storage battery is. A first fan is disposed between the storage battery and the electrical unit and configured to direct air from the storage battery toward the electrical unit.

Abstract: A storage battery system includes: a grid-connected storage battery; and a first current sensor that is provided in an electrical circuit linking the storage battery and the grid and detects a current in the electrical circuit the storage battery system having the electrical circuit connected with one or more power generators. The storage battery system includes: a second current sensor that is provided in the electrical circuit such that the one or more power generators are connected between the first current sensor and the second current sensor; and a controller that calculates generated power of the one or more power generators based on outputs obtained from the first current sensor and the second current sensor.

Abstract: This power supply device includes: a power interconnection path connecting a power interconnection port to a power conversion unit via a first switch; a stand-alone power supply path leading from an auxiliary input port via a second switch to an output port to which a load is connected; a storage-battery-side power supply path leading from a storage battery via the power conversion unit to the output port; and a control unit, the control unit causing the power conversion unit to charge/discharge the storage battery when interconnected with a commercial power grid, the control unit supplying power to the load via one of the stand-alone power supply path and the storage-battery-side power supply path when disconnected from the commercial power grid, the control unit switching the power supply path from the one to the other within an extremely short time period such as not to influence the load.

Abstract: This power conversion device includes: a power conversion unit 20 provided between a DC power supply 2 and an AC electric path 3 and configured to perform DC/AC power conversion; and a control unit 14 configured to control the power conversion unit 20. The control unit 14 includes a determination unit 25 configured to determine whether or not a starting current has flowed through the AC electric path 3, and an adjustment unit 26 configured to adjust an AC voltage generated by the power conversion unit 20, on the basis of a result of the determination by the determination unit 25.

Abstract: A storage battery system includes: a grid-connected storage battery; and a first current sensor that is provided in an electrical circuit linking the storage battery and the grid and detects a current in the electrical circuit the storage battery system having the electrical circuit connected with one or more power generators. The storage battery system includes: a second current sensor that is provided in the electrical circuit such that the one or more power generators are connected between the first current sensor and the second current sensor; and a controller that calculates generated power of the one or more power generators based on outputs obtained from the first current sensor and the second current sensor.

Abstract: A power storage device according to an aspect of the present disclosure includes: a casing including a bottom wall and a top wall opposite to the bottom wall; a storage battery; an electrical unit; and a cooling unit. The storage battery is disposed in the casing and separated from the bottom wall. The electrical unit is disposed in the casing and located closer to the top wall than the storage battery is. A first fan is disposed between the storage battery and the electrical unit and configured to direct air from the storage battery toward the electrical unit.

Abstract: A power conversion device includes a switch connected to an AC system; an AC/DC converter; and a DC/DC converter. A control unit compares an absolute value of an AC voltage target value based on the AC voltage with a DC voltage target value based on the storage battery voltage, and executes, on the basis of a magnitude relation of the values, a control method such that a period during which step-up operation is performed through switching operation mainly using one of the AC/DC converter and the DC/DC converter, and a period during which step-down operation is performed through switching operation mainly using the other one of the converters, alternately arise. When starting charging/discharging of the storage battery, the control unit causes the switch to close at zero cross timing of the AC voltage, and thereafter, causes charging/discharging to start from the switching operation through which the step-down operation is performed.

Abstract: This abnormality detection method for a single-phase AC input voltage is executed by a control unit having a function of a phase locked loop, and includes: sequentially generating a simulated voltage waveform with a phase synchronized with the input voltage, by using the phase locked loop; and within a period until a next update of the generated simulated voltage waveform, comparing the instantaneous value of the input voltage with the simulated voltage waveform, and when the instantaneous value of the input voltage changes from a state of being along the simulated voltage waveform to a state of not being along the simulated voltage waveform, determining that the input voltage is abnormal.

Abstract: This power supply device includes: an AC path from an input end to an output end; a current sensor configured to detect a current flowing through the AC path; a conversion unit connected to the AC path and being capable of bidirectional power conversion; a storage battery connected to the AC path via the conversion unit; an AC switch provided between the input end and a point at which the conversion unit is connected to the AC path, the AC switch including parallel body of a relay contact and a semiconductor switch; and a control unit configured to control the conversion unit and the AC switch. When the control unit executes a current conduction mode for the first time, and when the current sensor detects an excessive current during the current conduction mode, the control unit closes only the relay contact while keeping the semiconductor switch opened.

Abstract: This power conversion device includes: a power conversion unit 20 provided between a DC power supply 2 and an AC electric path 3 and configured to perform DC/AC power conversion; and a control unit 14 configured to control the power conversion unit 20. The control unit 14 includes a determination unit 25 configured to determine whether or not a starting current has flowed through the AC electric path 3, and an adjustment unit 26 configured to adjust an AC voltage generated by the power conversion unit 20, on the basis of a result of the determination by the determination unit 25.

Abstract: This power supply device includes: a power interconnection path connecting a power interconnection port to a power conversion unit via a first switch; a stand-alone power supply path leading from an auxiliary input port via a second switch to an output port to which a load is connected; a storage-battery-side power supply path leading from a storage battery via the power conversion unit to the output port; and a control unit, the control unit causing the power conversion unit to charge/discharge the storage battery when interconnected with a commercial power grid, the control unit supplying power to the load via one of the stand-alone power supply path and the storage-battery-side power supply path when disconnected from the commercial power grid, the control unit switching the power supply path from the one to the other within an extremely short time period such as not to influence the load.

Abstract: This conversion device converts DC powers from a plurality of DC power supplies, to AC power and supplies the AC power to a load. The conversion device includes: a filter circuit including an AC reactor and a first capacitor; a DC/AC inverter connected to the load via the filter circuit; DC/DC converters provided between the respective plurality of DC power supplies and the DC/AC inverter; a second capacitor provided between the DC/AC inverter and the DC/DC converters; and a control unit configured to set a current target value for each of the DC/DC converters to thereby be synchronized with current of the AC power, based on voltage of the AC power, voltage variation due to current flowing through the AC reactor and an impedance thereof, reactive currents respectively flowing through the first capacitor and the second capacitor, and voltage of each DC power.

Abstract: This power supply unit includes: an AC path from an input end to an output end; a first voltage sensor configured to detect an input voltage at the input end; a second voltage sensor configured to detect an output voltage at the output end; a bidirectional inverter connected to the AC path; a storage battery connected to the AC path via the bidirectional inverter; an AC switch provided between the input end and a point at which the bidirectional inverter is connected to the AC path; and a control unit configured such that, in a state in which the AC switch is controlled to be opened, if current conduction via the AC switch is detected on the basis of an operation state of the bidirectional inverter, the input voltage, and the output voltage, the control unit determines that the AC switch has failed, and stops the bidirectional inverter.

Abstract: Duties of control for DC/AC and DC/DC conversion units are determined by considering electric influences of a filter circuit, a capacitor connected to a DC bus, and a DC reactor for an output voltage command value for supplying an AC voltage to a load. The DC/DC conversion unit is controlled to convert a DC voltage into a DC bus voltage waveform alternately having a period of a pulsating current waveform corresponding to the absolute value of the AC voltage and a period of the DC voltage as a pulsating current minimum value. The DC/AC conversion unit is controlled to perform step-down operation during the period of the DC voltage and thus perform conversion into a waveform of the absolute value of the AC voltage corresponding to the period of the DC voltage, and also to perform polarity inversion per one pulsating current cycle.

Abstract: Control is performed such that, for generating an AC voltage from a DC voltage, a period during which a DC/DC converter boosts the DC voltage and an inverter performs one of polarity non-inversion passing and polarity inversion passing, and a period during which the DC/DC converter is stopped and the inverter performs step-down operation and one of polarity non-inversion passing and polarity inversion passing, arise alternately in one AC cycle. Gate blocking is temporarily performed for only the DC/DC converter, upon occurrence of a phenomenon in which, by start of power feeding to a load connected to an AC electric path, an absolute value of a current flowing through an AC reactor reaches a predetermined converter gate block threshold value lower than an instantaneous overcurrent protection threshold value.

Abstract: Control is performed such that, for generating an AC voltage from a DC voltage, a period during which a DC/DC converter boosts the DC voltage and an inverter performs one of polarity non-inversion passing and polarity inversion passing, and a period during which the DC/DC converter is stopped and the inverter performs step-down operation and one of polarity non-inversion passing and polarity inversion passing, arise alternately in one AC cycle. Gate blocking is temporarily performed for only the DC/DC converter, upon occurrence of a phenomenon in which, by start of power feeding to a load connected to an AC electric path, an absolute value of a current flowing through an AC reactor reaches a predetermined converter gate block threshold value lower than an instantaneous overcurrent protection threshold value.

Abstract: This power supply unit includes: an AC path from an input end to an output end; a first voltage sensor configured to detect an input voltage at the input end; a second voltage sensor configured to detect an output voltage at the output end; a bidirectional inverter connected to the AC path; a storage battery connected to the AC path via the bidirectional inverter; an AC switch provided between the input end and a point at which the bidirectional inverter is connected to the AC path; and a control unit configured such that, in a state in which the AC switch is controlled to be opened, if current conduction via the AC switch is detected on the basis of an operation state of the bidirectional inverter, the input voltage, and the output voltage, the control unit determines that the AC switch has failed, and stops the bidirectional inverter.

Abstract: This abnormality detection method for a single-phase AC input voltage is executed by a control unit having a function of a phase locked loop, and includes: sequentially generating a simulated voltage waveform with a phase synchronized with the input voltage, by using the phase locked loop; and within a period until a next update of the generated simulated voltage waveform, comparing the instantaneous value of the input voltage with the simulated voltage waveform, and when the instantaneous value of the input voltage changes from a state of being along the simulated voltage waveform to a state of not being along the simulated voltage waveform, determining that the input voltage is abnormal.

Abstract: This power supply device includes: an AC path from an input end to an output end; a current sensor configured to detect a current flowing through the AC path; a conversion unit connected to the AC path and being capable of bidirectional power conversion; a storage battery connected to the AC path via the conversion unit; an AC switch provided between the input end and a point at which the conversion unit is connected to the AC path, the AC switch including parallel body of a relay contact and a semiconductor switch; and a control unit configured to control the conversion unit and the AC switch. When the control unit executes a current conduction mode for the first time, and when the current sensor detects an excessive current during the current conduction mode, the control unit closes only the relay contact while keeping the semiconductor switch opened.

Abstract: A power conversion device includes a switch connected to an AC system; an AC/DC converter; and a DC/DC converter. A control unit compares an absolute value of an AC voltage target value based on the AC voltage with a DC voltage target value based on the storage battery voltage, and executes, on the basis of a magnitude relation of the values, a control method such that a period during which step-up operation is performed through switching operation mainly using one of the AC/DC converter and the DC/DC converter, and a period during which step-down operation is performed through switching operation mainly using the other one of the converters, alternately arise. When starting charging/discharging of the storage battery, the control unit causes the switch to close at zero cross timing of the AC voltage, and thereafter, causes charging/discharging to start from the switching operation through which the step-down operation is performed.