Abstract: The disclosed windfarm control system comprising a windfarm and a central controller; the windfarm including plural wind power generators whose rotational speeds are variable, plural aerographs disposed in the vicinity of the wind power generators to measure the directions and powers of the wind at the sites of the generators, and plural local controllers disposed in the vicinity of the wind power generators to control the output of the wind power generators by controlling the rotational speeds of the generators; wherein the central controller calculats the control level which maintains the output of the windfarm constant for a predetermined time period and instructs the local controllers to control the rpm's of the wind power generators in accordance with the control level.

Abstract: To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel to synchronizing the stator voltage with the grid voltage. The calculated compensation phase compensation value is used as an initial value for synchronizing at the next synchronizing operation.

Abstract: To control the receiving power, this invention uses a secondary battery to cut peaks of the receiving power. Further, this invention calculates the load power from the detected receiving power value and command values of the secondary battery in the controller and the power generating facility, and filters the load power to create command values of the fuel cells.

Abstract: A wind power generation system includes an excessive current consumption device, an AC input of which is connected between a generator rotor and an excitation converter on a system failure to detect a DC voltage ascent of the excitation converter and operate a shunt circuit on the system failure.

Abstract: A power generation apparatus and method includes an AC energization synchronous generator, a switching device which connects to a network disposed on a stator side of the AC energization synchronous generator, an energizing device which applies a variable frequency AC to a secondary winding of the AC energization synchronous generator, and a first voltage detection unit which detects a voltage of the switching device on the stator side. A rotational frequency of the AC energization synchronous generator is estimated or calculated based on a frequency of a stator side voltage of the switching device, while the switching device is open.

Abstract: A wind power generation system includes: a wind turbine in which at least one blade is mounted on an axis; a generator for generating multiphase alternating current power by rotation of the axis; and a multiphase power conversion device for performing PWM-control for adjustment and output of generated power of the generator. With the configuration, the PWM-control provides for each phase a control paused period in which no overlap occurs. Thus, the pulse density between the control period and the control paused period of other phases is low, thereby generating high and low density in an inter-phase pulse.

Abstract: A distributed generation system that can suppress a voltage fluctuation caused by a distributed generation by an apparatus of a small power capacity in the distributed generation itself and stabilize the power system voltage without inserting interharmonic voltage or current into the power system and without interference among a plurality of distributed generations. Parameter ?(t) varying with time is estimated based on fluctuating component ?P of the active power P generated by the distributed generation and the voltage fluctuating component ?V attributable to the distributed generation developed at the point of connection between the distributed generation and power system. The distributed generation produces reactive power Q=??P or Q=???P, to thereby suppresses only the voltage fluctuation of the power system attributable to the distributed generation.

Abstract: A power system control apparatus which controls a power system electrically connected to a wind power generation apparatus having a wind turbine which receives wind and rotates, a generator which generates electric power by the rotating wind turbine, and a power converter which converts the electric power generated by the generator. The power system control apparatus includes a voltage detector for detecting a voltage of the power system, a reactive power command value generation unit for generating a reactive power command value from a voltage detection value of the voltage detector, and a transmission unit for transmitting the reactive power command value to the wind power generation apparatus. Output fluctuation of the generator is suppressed, and reactive power according to the reactive power command value is transmitted from the wind power generation apparatus to the power system.

Abstract: To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel to synchronizing the stator voltage with the grid voltage. The calculated compensation phase compensation value is used as an initial value for synchronizing at the next synchronizing operation.

Abstract: In a wind power generation system, an AC input of a unit for coping with system faults is connected to an excitation converter and a DC port of the unit for coping with system faults is connected to a DC port of a converter through resistors. A plurality of energy consumptive circuits each constructed of a resistor and switching units are provided for the DC port of the unit for coping with system faults.

Abstract: In a controller for a windfarm including a plurality of wind turbine generators controllable in rotation frequency and pith of blades of the wind turbine generators, coupled to a grid through a transmission line, an anemometer is provided to each wind turbine generator to transmits wind direction and wind speed data to a central controller which process the wind direction and wind speed data to transmit an output command each wind turbine generator. The central controller predicts, on the basis of the wind speed detected by the upstream wind turbine generator, variation in wind speed at other wind turbine generators to control the output of the windfarm. The output power may be limited or charging energy as rotation energy of blades and discharging the rotation energy as output power in addition to a battery unit for averaging.

Abstract: A wind turbine-driven hydrogen production system controlling a power converter system such that the wind turbine stays in its operable range for a longer time and thus the hydrogen production system produces hydrogen for a longer time. The wind turbine-driven hydrogen production system varies an amount of electrical current supplied to an electrolytic hydrogen production system according to the rotational speed of the wind turbine to reduce variations in the rotational speed. Furthermore, the pitch angle of the wind turbine varies according to the speed. Thus, variations in the speed of the wind turbine can be reduced. A permanent-magnet generator is used as the electricity generator of the wind turbine to obtain a power supply at start-up. Alternatively, a power storage system used as assistive equipment at start-up is supplementarily added or only a power supply for the controllers is supplied from a system.

Abstract: A wind turbine generator system can regulate the rotational velocity of the wind turbine within an operation range even when the wind velocity suddenly changes and can perform continuous operation of the wind turbine. The wind turbine generator system includes a generator connected to the shaft of the wind turbine and a converter connected to the generator. When the rotational velocity of the wind turbine is within a predetermined range, power outputted from the generator is controlled so as to follow the instruction concerning the generator output given from the wind turbine to the converter. When the rotational velocity of the wind turbine is out of the predetermined range, the power outputted from the generator is controlled without following the instruction concerning generator output given from the wind turbine to the converter.

Abstract: A distributed generation system that can suppress a voltage fluctuation caused by a distributed generation by an apparatus of a small power capacity in the distributed generation itself and stabilize the power system voltage without inserting interharmonic voltage or current into the power system and without interference among a plurality of distributed generations. Parameter ?(t) varying with time is estimated based on fluctuating component ?P of the active power P generated by the distributed generation and the voltage fluctuating component ?V attributable to the distributed generation developed at the point of connection between the distributed generation and power system. The distributed generation produces reactive power Q=??P or Q=???P, to thereby suppresses only the voltage fluctuation of the power system attributable to the distributed generation.

Abstract: A variable speed wind power generation system including a wind turbine, a generation power command unit for generating a generation power command value based on a state quantity of the wind turbine and a generator control unit for controlling the power converter for controlling electric power of the generator, wherein the generator control unit operates to regulate the generation power of the generator in order to change the generation power amount according to the generation power command value.

Abstract: An interface device transmits a reactive power command depending on a power system from a voltage regulation device of the power system to a wind power generation apparatus electrically connected to the power system, and the wind power generation apparatus receives the reactive power command. Then, the wind power generation apparatus outputs reactive power according to a value obtained by adding, to a reactive power command, another reactive power command for suppression of voltage fluctuation caused by output power of the wind power generation apparatus.

Abstract: To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel to synchronizing the stator voltage with the grid voltage. The calculated compensation phase compensation value is used as an initial value for synchronizing at the next synchronizing operation.

Abstract: In a wind turbine generator system including an AC exciting converter a grid side converter, and a controller configured to control the AC-exciting converter and the grid side converter, the controller operates a short-circuiting circuit when decrease in the grid voltage and increase in the DC voltage are detected.

Abstract: A wind turbine generator system can regulate the rotational velocity of the wind turbine within an operation range even when the wind velocity suddenly changes and can perform continuous operation of the wind turbine. The wind turbine generator system includes a generator connected to the shaft of the wind turbine and a converter connected to the generator. When the rotational velocity of the wind turbine is within a predetermined range, power outputted from the generator is controlled so as to follow the instruction concerning the generator output given from the wind turbine to the converter. When the rotational velocity of the wind turbine is out of the predetermined range, the power outputted from the generator is controlled without following the instruction concerning generator output given from the wind turbine to the converter.

Abstract: A wind power generation system wherein procedure for controlling the blade pitch is changed in accordance with the rate of decrease in the amplitude of the grid voltage, and when over current occurs in the grid-side power converter, the grid-side power converter is brought into the gate-blocked condition whereas the generator-side power converter continues its operation.