Abstract: A solar power generation system includes an inverter configured to convert DC power inputted from a solar battery to AC power, a MPPT control section configured to perform maximum power point tracking control on the inverter, an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control, an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state, and a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section.

Abstract: A solar power generation system includes an inverter configured to convert DC power inputted from a solar battery to AC power, a MPPT control section configured to perform maximum power point tracking control on the inverter, an input power measurement section configured to measure the DC power inputted to the inverter at a time of avoiding a transient state due to variation in DC voltage of the inverter by the maximum power point tracking control, an output power measurement section configured to measure the AC power outputted from the inverter at the time of avoiding the transient state, and a conversion efficiency computation section configured to compute conversion efficiency of the inverter based on the DC power measured by the input power measurement section and the AC power measured by the output power measurement section.

Abstract: A method for producing poly(dimethyl vinylphosphonate) from a monomer component mainly containing dimethyl vinylphosphonate by anionic polymerization in the presence of an anionic polymerization initiator, the method being characterized in that an aliphatic ether is used as a polymerization solvent, and a method for producing poly(vinylphosphonic acid) characterized in that the poly(dimethyl vinylphosphonate) obtained by the former method is hydrolyzed in the presence of an acid are provided. The methods make it possible to easily produce a poly(dimethyl vinylphosphonate) which has a high molecular weight and in which the molecular weight is controlled, and make it possible to produce a poly(vinylphosphonic acid) which has a high molecular weight and in which the molecular weight is controlled corresponding to the poly(dimethyl vinylphosphonate).

Abstract: There is provided a fault detecting apparatus for detecting a fault in an electric circuit including connecting circuits and an aggregating circuit. The fault detecting apparatus includes a fault detector that detects a fault when at least one of connecting circuit current detectors detects that a current flows and an aggregating current detector detects that a current does not flow.

Abstract: There is provided a power supply apparatus for power converters which convert power generated by power generators into power to be supplied to a power system. The power supply apparatus includes a photovoltaic power cell for the power converters, the photovoltaic power cells generating power for supplying power of the power converters.

Abstract: A method for producing poly(dimethyl vinylphosphonate) from a monomer component mainly containing dimethyl vinylphosphonate by anionic polymerization in the presence of an anionic polymerization initiator, the method being characterized in that an aliphatic ether is used as a polymerization solvent, and a method for producing poly(vinylphosphonic acid) characterized in that the poly(dimethyl vinylphosphonate) obtained by the former method is hydrolyzed in the presence of an acid are provided. The methods make it possible to easily produce a poly(dimethyl vinylphosphonate) which has a high molecular weight and in which the molecular weight is controlled, and make it possible to produce a poly(vinylphosphonic acid) which has a high molecular weight and in which the molecular weight is controlled corresponding to the poly(dimethyl vinylphosphonate).

Abstract: A power conversion apparatus includes an inverter circuit including a switching element, a system voltage measurement unit measuring a system voltage of a power system, a voltage drop detector detecting a voltage drop of the power system, a carrier wave generator generating a carrier wave, a carrier wave frequency modulator increasing a frequency of the carrier wave, when the voltage drop is detected, a signal wave generator generating a signal wave to control the inverter circuit, a gate signal generator comparing the carrier wave with the signal wave, and generating a gate signal, and a power conversion controller controlling the inverter circuit, based on the gate signal.

Abstract: There is provided a solar power generation system including a solar cell, an inverter converting a direct current power generated by the solar cell into an alternating current power, a system voltage measurement unit measuring a system voltage, a voltage drop detector detecting a voltage drop of a power system, based on the system voltage, a first direct current voltage controller controlling a direct current voltage of the inverter to enhance a power generation efficiency of the solar cell, when the voltage drop is not detected, and a second direct current voltage controller controlling the direct current voltage of the inverter to suppress a current output from the inverter, when the voltage drop is detected.

Abstract: A grounding apparatus includes a current detector configured to detect a current flowing in the ground line, a fuse inserted in series in a part of the around line and configured to melt when the current flowing in the ground line exceeds the first protection setting value, not destroying the current detector, and then exceeds the first protection setting value, causing a complete grounding fault, and a determination device configured to give an open command to the circuit breaker when the current detected by the current detector exceeds the first protection setting value of the circuit breaker.

Abstract: A power converter apparatus is provided with a lead-in board in which alternating-current power received from power converting units is connected in parallel, and a connection base including frames for installing the power converting units therein. The frames are provided with connection sections for connecting the main circuits of the power converting units. The lead-in board is provided with breakers for cut off alternating-current power from the power converting units.

Abstract: There is provided a fault detection apparatus including an open/close unit configured to open/close an electric path to pass a direct current forward, a reverse-current detector configured to detect a reverse current running through the electric path backward, and an opening unit configured to open the open/close unit when the reverse current is detected by the reverse-current detector.

Abstract: A photovoltaic power generation system includes a photovoltaic array including photovoltaic modules, the photovoltaic power generation system further includes a control apparatus configured to display output characteristics of the photovoltaic array and power generating conditions of the photovoltaic array in synchronization.

Abstract: A power converter includes a power conversion circuit including a switching element, a device including an inductance and provided on an AC side of the power conversion circuit, an output-amount measuring module configured to measure an output amount of an output from the power conversion circuit, and a switching frequency determining module configured to determine a switching frequency at which the switching element is switched to reduce a loss including a loss due to the device, based on the output amount measured by the output-amount measuring module.

Abstract: A power conversion apparatus includes an inverter circuit, a system voltage measurement unit measuring a system voltage, a voltage drop detector detecting a voltage drop of a power system, based on the system voltage, a direct current power measurement unit measuring a direct current power to be input into the inverter circuit, an alternating current command value calculator calculating an alternating current command value to control an alternating current output from the inverter circuit, based on the direct current power and the system voltage, and a current limiter that decrease a current limit value to limit the alternating current command value, when the voltage drop is detected.

Abstract: There is provided a power supply apparatus for power converters which convert power generated by power generators into power to be supplied to a power system. The power supply apparatus includes a photovoltaic power cell for the power converters, the photovoltaic power cells generating power for supplying power of the power converters.

Abstract: There is provided a fault detecting apparatus for detecting a fault in an electric circuit including connecting circuits and an aggregating circuit. The fault detecting apparatus includes a fault detector that detects a fault when at least one of connecting circuit current detectors detects that a current flows and an aggregating current detector detects that a current does not flow.

Abstract: A power conversion apparatus includes a comparison circuit which compares a determination element related to a loss in the power converter with a switching reference value and outputs a determination instruction when a difference has occurred between them, a determination circuit which outputs a two-level operation switching instruction when the determination element is greater than or equal to the switching reference value, and a switching circuit which, when having received a two-level operation switching instruction, turns off the alternating-current switch and turns on the valve devices in the arm sequentially, thereby bringing the power converter into a two-level operation state.

Abstract: There is provided a solar power generation system including a solar cell, an inverter converting a direct current power generated by the solar cell into an alternating current power, a system voltage measurement unit measuring a system voltage, a voltage drop detector detecting a voltage drop of a power system, based on the system voltage, a first direct current voltage controller controlling a direct current voltage of the inverter to enhance a power generation efficiency of the solar cell, when the voltage drop is not detected, and a second direct current voltage controller controlling the direct current voltage of the inverter to suppress a current output from the inverter, when the voltage drop is detected.

Abstract: A power conversion apparatus includes an inverter circuit including a switching element, a system voltage measurement unit measuring a system voltage of a power system, a voltage drop detector detecting a voltage drop of the power system, a carrier wave generator generating a carrier wave, a carrier wave frequency modulator increasing a frequency of the carrier wave, when the voltage drop is detected, a signal wave generator generating a signal wave to control the inverter circuit, a gate signal generator comparing the carrier wave with the signal wave, and generating a gate signal, and a power conversion controller controlling the inverter circuit, based on the gate signal.

Abstract: A power conversion apparatus includes an inverter circuit, a system voltage measurement unit measuring a system voltage, a voltage drop detector detecting a voltage drop of a power system, based on the system voltage, a direct current power measurement unit measuring a direct current power to be input into the inverter circuit, an alternating current command value calculator calculating an alternating current command value to control an alternating current output from the inverter circuit, based on the direct current power and the system voltage, and a current limiter that decrease a current limit value to limit the alternating current command value, when the voltage drop is detected.