Abstract: According to one embodiment, a pumped-storage power generation control device includes a control section that controls at least one of the pumping input of the pumped-storage power generation facility in the pumping operation and the power output of the pumped-storage power generation facility in the power generating operation such that a value, which is obtained by a predetermined calculation using the measurement value relating to the pumping input of the pumped-storage power generation facility in the pumping operation and the measurement value relating to the power output of the pumped-storage power generation facility in the power generating operation, becomes a set target value.

Abstract: According to one embodiment, a control system includes a chopper, a short-circuit unit, a voltage detector circuit, and a controller. The chopper reduces a direct current voltage between a converter connected to a stator in a wound induction machine and an inverter connected to a rotor in the wound induction machine. The short-circuit unit shorts a wire used for connection between the rotor and the inverter and the voltage detector circuit is to detect the direct current voltage. The controller causes driving the chopper and, at the same time, outputting from the inverter an alternating current over which a direct current component is superimposed when a voltage value exceeds a first predetermined value, and causes driving the short-circuit unit and, at the same time, halting the inverter when the voltage value exceeds a second predetermined value.

Abstract: According to one embodiment, a control system includes a chopper, a short-circuit unit, a voltage detector circuit, and a controller. The chopper reduces a direct current voltage between a converter connected to a stator in a wound induction machine and an inverter connected to a rotor in the wound induction machine. The short-circuit unit shorts a wire used for connection between the rotor and the inverter and the voltage detector circuit is to detect the direct current voltage. The controller causes driving the chopper and, at the same time, outputting from the inverter an alternating current over which a direct current component is superimposed when a voltage value exceeds a first predetermined value, and causes driving the short-circuit unit and, at the same time, halting the inverter when the voltage value exceeds a second predetermined value.

Abstract: According to one embodiment, there is provided a control device of a secondary excitation device which supplies a rotary machine with a voltage or current of a variable frequency. The control device includes a harmonic frequency calculation unit which calculates a frequency of a specific harmonic generated on a primary side of the rotary machine by using a slip frequency or rotation speed of the rotary machine and a carrier frequency of the secondary excitation device, and a carrier frequency correction unit which corrects the carrier frequency of the secondary excitation device such that the frequency of the specific harmonic calculated by the harmonic frequency calculation unit falls within a given band.

Abstract: According to one embodiment, a pumped-storage power generation control device includes a control section that controls at least one of the pumping input of the pumped-storage power generation facility in the pumping operation and the power output of the pumped-storage power generation facility in the power generating operation such that a value, which is obtained by a predetermined calculation using the measurement value relating to the pumping input of the pumped-storage power generation facility in the pumping operation and the measurement value relating to the power output of the pumped-storage power generation facility in the power generating operation, becomes a set target value.

Abstract: A wind farm output control device includes a potential estimator estimating a maximum electrical energy outputtable by each wind power generation device, a control amount determiner determining, based on the estimated maximum power amount, a control amount for an effective power of each wind power generation device and/or a reactive power thereof in a wind farm, and a control amount distributor distributing the control amount based on an available power generation amount of each wind power generation device. The potential estimator estimates the maximum power amount based on a pitch angle of blades, an angular speed deviation of a power generator, and a conversion loss of the wind power generation device. Within the range of the estimated maximum power amount, the control amount for the output by the wind farm is distributed within a range where each wind power generation device is outputtable according to the wind condition.

Abstract: According to one embodiment, there is provided a control device of a secondary excitation device which supplies a rotary machine with a voltage or current of a variable frequency. The control device includes a harmonic frequency calculation unit which calculates a frequency of a specific harmonic generated on a primary side of the rotary machine by using a slip frequency or rotation speed of the rotary machine and a carrier frequency of the secondary excitation device, and a carrier frequency correction unit which corrects the carrier frequency of the secondary excitation device such that the frequency of the specific harmonic calculated by the harmonic frequency calculation unit falls within a given band.

Abstract: In one embodiment, a control system of a variable speed pumped storage hydropower system includes an optimization processing unit configured to calculate a flow rate adjusting valve opening demand value and a first command value, a speed control unit configured to generate a secondary current active power component command value of a secondary excitation device based on the first command value, a mechanical (pump-turbine) output compensation unit configured to calculate a compensation value of the opening of the flow rate adjusting valve and/or a compensation value of the generator-motor output, and an output control unit configured to generate a flow rate adjusting valve opening command value based on the generator-motor output command value, the flow rate adjusting valve opening demand value, the compensation value calculated by the mechanical output compensation unit, and the output detection value of the generator-motor.

Abstract: According to one embodiment, there is provided a generator excitation apparatus including a plurality of first power converters and a second power converter. The plurality of first power converters are electrically connected to windings of respective phases of rotors of a wound rotor type induction generator in which the windings of the rotors of the respective phases are electrically independent, and are configured to bidirectionally convert DC and AC. The second power converter is configured to bidirectionally convert DC and AC between DC sides of the first power converters and a three-phase DC power supply. The DC sides of the first power converters are electrically connected together to a DC side of the second power converter.

Abstract: According to one embodiment, a test apparatus for a variable speed controller is provided. A generator motor computation unit computes behaviors of the generator motor, using a state quantity regarding the generator motor and a predetermined transfer function. An AC machine computation unit computes behaviors of the AC machine, using a state quantity regarding the AC machine and a predetermined transfer function. A power converter computation unit computes behaviors of the power converter, using a state quantity regarding the power converter and a predetermined transfer function. Each of the computation units uses computation results of other computation units.

Abstract: According to one embodiment, there is provided a generator excitation apparatus including a plurality of first power converters and a second power converter. The plurality of first power converters are electrically connected to windings of respective phases of rotors of a wound rotor type induction generator in which the windings of the rotors of the respective phases are electrically independent, and are configured to bidirectionally convert DC and AC. The second power converter is configured to bidirectionally convert DC and AC between DC sides of the first power converters and a three-phase DC power supply. The DC sides of the first power converters are electrically connected together to a DC side of the second power converter.

Abstract: In one embodiment, a control system of a variable speed pumped storage hydropower system includes an optimization processing unit configured to calculate a flow rate adjusting valve opening demand value and a first command value, a speed control unit configured to generate a secondary current active power component command value of a secondary excitation device based on the first command value, a mechanical (pump-turbine) output compensation unit configured to calculate a compensation value of the opening of the flow rate adjusting valve and/or a compensation value of the generator-motor output, and an output control unit configured to generate a flow rate adjusting valve opening command value based on the generator-motor output command value, the flow rate adjusting valve opening demand value, the compensation value calculated by the mechanical output compensation unit, and the output detection value of the generator-motor.

Abstract: A wind farm output control device includes a potential estimator estimating a maximum electrical energy outputtable, by each wind power generation device, a control amount determiner determining, based on the estimated maximum power amount, a control amount for an effective power of each wind power generation device and/or a reactive power thereof in a wind farm, and a control amount distributor distributing the control amount based on an available power generation amount of each wind power generation device. The potential estimator estimates the maximum power amount based on a pitch angle of blades, an angular speed deviation of a power generator, and a conversion loss of the wind power generation device. Within the range of the estimated maximum power amount, the control amount for the output by the wind farm is distributed within a range where each wind power generation device is outputtable according to the wind condition.

Abstract: A control apparatus for a power converter having a plurality of semiconductor switching devices that converts DC power into AC power and outputs three levels of voltages, including a command voltage generator configured to output a command voltage vector that represents a voltage to be output from the power converter, an integrator configured to calculate a difference integral vector by integrating a difference between the command voltage vector and an output voltage vector that represents a voltage command for the power converter, a difference vector calculator configured to calculate difference vectors by subtracting the command voltage vector from each of the possible output voltage vectors, a vector selector configured to select one of the possible output voltage vectors which corresponds to one of the difference vectors making the largest angle with the difference integral vector as the output voltage vector only if the difference integral vector exceeds a predetermined value, and a gate signal generator

Abstract: An overvoltage protection circuit including a plurality of series connected thyristors having an overvoltage protection function and a plurality of impedance circuits. Each of the impedance circuits is connected in parallel with one of the thyristors, respectively. The impedance circuits include at least a first impedance circuit having a first impedance value and a second impedance circuit having a second impedance value which is different from the first impedance value.