Abstract: A single-crystal diamond, wherein the single-crystal diamond has an average of a phase difference per unit thickness of 10 nm/mm or less, and the phase difference has a standard deviation of 5 nm/mm or less.

Abstract: A single-crystal diamond having an X-ray diffraction rocking curve with a half-width of 20 seconds or less, wherein the half-width of the X-ray diffraction rocking curve is measured with CuK? radiation in a (004) plane parallel arrangement using a diamond crystal as a first crystal in X-ray diffraction by a double-crystal method, a peak at a Raman shift in the range of 1332 cm?1 to 1333 cm?1 in a Raman spectrum has a half-width of 2.0 cm?1 or less, the single-crystal diamond has an etch-pit density of 10,000/cm2 or less, the etch-pit density is measured in an etching test, and the single-crystal diamond has a nitrogen content of more than 0.1 ppm and 50 ppm or less based on the number of atoms.

Abstract: An objective is to prevent excessive temperature decrease of cooling water and to reduce energy loss by a heater. A water-cooled electrical apparatus includes an electrical device 2 placed indoors, a pump 3 for circulating cooling water for cooling the electrical device, a cooler 5, placed outdoors, for cooling the cooling water, a heater 6 for heating the cooling water, and a main pipe 4 forming a closed loop so that the cooling water circulates through the electrical device, the pump, the cooler, and the heater. The water-cooled electrical apparatus further includes a bypass pipe 11 bypassing between bifurcations 9 and 10, provided at inlet and outlet sides of the cooler, for flow-dividing the cooling water, and at least one of a first flow amount control valve 7 provided along the main pipe between the bifurcations, and a second flow amount control valve 12 provided along the bypass pipe.

Abstract: An inverter apparatus converts a DC power of a capacitor charged via a rectifier circuit connected to a first AC power system into an AC power, and supplies the AC power to a second AC power system. The inverter apparatus includes a discharge circuit, a control circuit, a trigger circuit, a first voltage-sag detection circuit, a control power circuit, and a second voltage-sag detection circuit. When the second voltage-sag detection circuit detects a voltage sag of the control power circuit below a threshold, the trigger circuit generates a discharge command signal for causing the discharge circuit to discharge a charge from the capacitor.

Abstract: A SVC control section detects a bus voltage from an instrument transformer, and adjusts reactive power generated by a SVC according to the detected bus voltage. A cooperative control section generates a control command for controlling the interconnection and parallel-off of a phase lead capacitor and a phase lag reactor on the basis of the amount of reactive power generated by the SVC and the bus voltage detected by the instrument transformer and a voltage sensor. A voltage comparator compares the bus voltage with a predetermined threshold voltage set to a voltage lower than a lower limit value of a steady state fluctuation range of the bus voltage and outputs the comparison result to a circuit breaker control section. When the bus voltage is lower than the threshold voltage, the circuit breaker control section locks the control command from the cooperative control section.

Abstract: An inverter apparatus converts a DC power of a capacitor charged via a rectifier circuit connected to a first AC power system into an AC power, and supplies the AC power to a second AC power system. The inverter apparatus includes a discharge circuit, a control circuit, a trigger circuit, a first voltage-sag detection circuit, a control power circuit, and a second voltage-sag detection circuit. When the second voltage-sag detection circuit detects a voltage sag of the control power circuit below a threshold, the trigger circuit generates a discharge command signal for causing the discharge circuit to discharge a charge from the capacitor.

Abstract: A reactive power control apparatus for an AC power system includes a reactive power compensation device, a compensation capacitor device and a compensation capacitor control device. The compensation capacitor control device includes a detection voltage output circuit which outputs a bus detection voltage after the clearing of a voltage drop abnormality, corresponding to the AC voltage of a system bus after the voltage drop abnormality that occurred in the AC power system has been cleared, and a compensation capacitor control circuit which controls the connection status of a compensation capacitor with respect to the system bus. The compensation capacitor control circuit controls the connection status of the compensation capacitor with respect to the system bus, on the basis of the voltage level of the bus detection voltage after the clearing of the voltage drop abnormality.

Abstract: A SVC control section detects a bus voltage from an instrument transformer, and adjusts reactive power generated by a SVC according to the detected bus voltage. A cooperative control section generates a control command for controlling the interconnection and parallel-off of a phase lead capacitor and a phase lag reactor on the basis of the amount of reactive power generated by the SVC and the bus voltage detected by the instrument transformer and a voltage sensor. A voltage comparator compares the bus voltage with a predetermined threshold voltage set to a voltage lower than a lower limit value of a steady state fluctuation range of the bus voltage and outputs the comparison result to a circuit breaker control section. When the bus voltage is lower than the threshold voltage, the circuit breaker control section locks the control command from the cooperative control section.

Abstract: A reactive power control apparatus for an AC power system includes a reactive power compensation device, a compensation capacitor device and a compensation capacitor control device. The compensation capacitor control device includes a detection voltage output circuit which outputs a bus detection voltage after the clearing of a voltage drop abnormality, corresponding to the AC voltage of a system bus after the voltage drop abnormality that occurred in the AC power system has been cleared, and a compensation capacitor control circuit which controls the connection status of a compensation capacitor with respect to the system bus. The compensation capacitor control circuit controls the connection status of the compensation capacitor with respect to the system bus, on the basis of the voltage level of the bus detection voltage after the clearing of the voltage drop abnormality.