Abstract: According to one embodiment, a solar cell system includes a first solar cell, a first electric circuit and controller. The first solar cell is provided on a hood of a vehicle. The first electric circuit is connected to the first solar cell. The controller is configured to electrically connect the first solar cell with the first electric circuit in a case where a traveling speed of the vehicle is less than a first threshold, and electrically disconnect the first solar cell from the first electric circuit in a case where the traveling speed of the vehicle is equal to or greater than the first threshold.

Abstract: According to one embodiment, a power supply/demand device includes a virtual synchronous inverter and a storage battery. The virtual synchronous inverter is connected to a power system. Charging and discharging of the storage battery are controlled by the virtual synchronous inverter. The virtual synchronous inverter is connected to the power system in parallel with other inverters. The virtual synchronous inverter is capable of calculating a first standby time having any length and performing control of the storage battery corresponding to an operation instruction after a lapse of the first standby time, when receiving the operation instruction accompanied by output of power to the power system or input of power from the power system.

Abstract: A bypass circuit of an embodiment includes a switch that shorts-circuit between a first power conversion apparatus and a power storage apparatus. The switch is connected in parallel to a second power conversion apparatus. The first power conversion apparatus converts power generated from natural energy and outputs the converted power to a power distribution grid. The second power conversion apparatus converts surplus power that has not been converted by the first power conversion apparatus and charges the power storage apparatus with the converted power; or converts power discharged from the power storage apparatus and supplies the converted power to the first power conversion apparatus.

Abstract: According to one embodiment, a power supply device connected to a power grid is provided. The power supply device includes an inverter, a control unit configured to control operation of the inverter using a first parameter value so as to simulate characteristics of a synchronous generator, and an acquisition unit configured to obtain a second parameter value different from the first parameter value. The control unit is configured to control the operation of the inverter by changing the first parameter value to the acquired second parameter value.

Abstract: A control apparatus controlling a power output apparatus that generates, based on input power from one of an electrical grid and a power storage, output power to another of the electrical grid and the power storage is provided. The control apparatus includes: a communicator to receive a grid frequency of the electrical grid and a state of charge of the power storage, or information allowing the grid frequency and the state of charge to be calculated; and a processor to determine an output destination and an output rate of the output power, based on a function of calculating the output destination and the output rate according to the grid frequency. The output destination and the output rate are adjusted according to the state of charge, by the processor changing, according to the state of charge, the function used to determine the output destination and the output rate.

Abstract: According to one embodiment, a detection apparatus includes a pair of conductors configured to detect an electromagnetic wave occurring due to a discharge phenomenon in a target apparatus, wherein the pair of conductors are arranged in a near field region of the target apparatus in which the electromagnetic wave occurs.

Abstract: According to one embodiment, a detection apparatus includes a pair of conductors configured to detect an electromagnetic wave occurring due to a discharge phenomenon in a target apparatus, wherein the pair of conductors are arranged in a near field region of the target apparatus in which the electromagnetic wave occurs.

Abstract: According to one embodiment, a charging system charges a secondary battery provided in a mobile body. The charging system includes a controller which selects one of a first charge mode which charges the secondary battery by simulating a synchronous generator and a second charge mode which charges the secondary battery without simulating the synchronous generator, and a charger which charges the secondary battery by an operation corresponding to the first charge mode or the second charge mode selected by the controller.

Abstract: A power conditioning system includes a control circuit. The control circuit is configured to switch a output control mode to any one of a first mode in which an operation not based on inertia is executed and a second mode in which an operation based on inertia is executed, performs output control according to a first rating in the first mode, and performs output control according to a second rating different from the first rating in the second mode.

Abstract: A spark discharge detection device includes a discharge detector, a waveform extension circuit, and determination circuit. The discharge detector includes a metal electrode that detects discharge between an electrode and a sliding body that is in contact with and sliding surface of the electrode. The waveform extension circuit configured to extend a discharge waveform output from the discharge detector in a time direction. The determination circuit configured to determine that discharge has occurred in the sliding body when a signal value exceeds a first threshold and a time during which the signal value exceeds the first threshold is held for a time longer than a first time for the output of the waveform extension circuit.

Abstract: A bypass circuit of an embodiment includes a switch that shorts-circuit between a first power conversion apparatus and a power storage apparatus. The switch is connected in parallel to a second power conversion apparatus. The first power conversion apparatus converts power generated from natural energy and outputs the converted power to a power distribution grid. The second power conversion apparatus converts surplus power that has not been converted by the first power conversion apparatus and charges the power storage apparatus with the converted power; or converts power discharged from the power storage apparatus and supplies the converted power to the first power conversion apparatus.

Abstract: According to one embodiment, a detection apparatus includes a pair of conductors configured to detect an electromagnetic wave occurring due to a discharge phenomenon in a target apparatus, wherein the pair of conductors are arranged in a near field region of the target apparatus in which the electromagnetic wave occurs.

Abstract: According to one embodiment, a voltage control inverter interconnectable with an electric power system, includes: a voltage detecting circuit configured to detect a first voltage that is a voltage of the electric power system; and a voltage output circuit configured to output a second voltage to the electric power system at a timing depending on a value of the first voltage, the second voltage having a value depending on the value of the first voltage.

Abstract: According to one embodiment, a voltage control inverter interconnectable with a power system, includes receiving circuitry configured to receive a first control command for outputting a voltage to the power system; and controlling circuitry configured to execute the first control command to output the voltage to the power system. The controlling circuitry is configured to skip to execute the first control command in response to the first control command being received during a period in which the power system is in a first state that is different from a normal state.

Abstract: A control apparatus controlling a power output apparatus that generates, based on input power from one of an electrical grid and a power storage, output power to another of the electrical grid and the power storage is provided. The control apparatus includes: a communicator to receive a grid frequency of the electrical grid and a state of charge of the power storage, or information allowing the grid frequency and the state of charge to be calculated; and a processor to determine an output destination and an output rate of the output power, based on a function of calculating the output destination and the output rate according to the grid frequency. The output destination and the output rate are adjusted according to the state of charge, by the processor changing, according to the state of charge, the function used to determine the output destination and the output rate.

Abstract: According to one embodiment, a voltage control inverter interconnectable with an electric power system, includes: a voltage detecting circuit configured to detect a first voltage that is a voltage of the electric power system; and a voltage output circuit configured to output a second voltage to the electric power system at a timing depending on a value of the first voltage, the second voltage having a value depending on the value of the first voltage.

Abstract: According to one embodiment, a voltage control inverter interconnectable with a power system, includes receiving circuitry configured to receive a first control command for outputting a voltage to the power system; and controlling circuitry configured to execute the first control command to output the voltage to the power system. The controlling circuitry is configured to skip to execute the first control command in response to the first control command being received during a period in which the power system is in a first state that is different from a normal state.

Abstract: An electronic circuit to receive input AC signals having different phases, and to control bidirectional switches corresponding to phases to generate, based on input AC signals having the phases, output AC signals having the phases and having a frequency different from a frequency of the input AC signals, the electronic circuit has reference signal circuitry to generate a reference signal having a frequency higher than the frequency of the output AC signals, and a commutation circuitry to control switching between voltage commutation and current commutation, wherein, in the voltage commutation, the commutation circuitry switches the bidirectional switches corresponding to the phases in sequence based on a voltage level of the output AC signals of the phases before and after a time point when an amplitude of the reference signal becomes a specific amplitude value, and in the current commutation, the commutation circuitry switches the bidirectional switches in parallel.

Abstract: According to one embodiment, power transmission circuitry configured to generate a magnetic field by AC current flowing through a coil, and to transmit AC power by coupling the magnetic field with a coil of a power reception apparatus, wherein a frequency of the AC current is higher than a frequency of AC power supply to the power transmission apparatus; and control circuitry configured to change a frequency of the AC current in accordance with a first order of first to n-th frequencies during a power transmission of the power transmission circuitry, wherein the first order comprises each of the first to n-th frequencies one time.

Abstract: An electronic circuit to receive input AC signals having different phases, and to control bidirectional switches corresponding to phases to generate, based on input AC signals having the phases, output AC signals having the phases and having a frequency different from a frequency of the input AC signals, the electronic circuit has reference signal circuitry to generate a reference signal having a frequency higher than the frequency of the output AC signals, and a commutation circuitry to control switching between voltage commutation and current commutation, wherein, in the voltage commutation, the commutation circuitry switches the bidirectional switches corresponding to the phases in sequence based on a voltage level of the output AC signals of the phases before and after a time point when an amplitude of the reference signal becomes a specific amplitude value, and in the current commutation, the commutation circuitry switches the bidirectional switches in parallel.