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 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: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.

Abstract: An excitation power converter of a doubly-fed generator is protected from excess current to be caused by ground fault or system disturbance and operation continuity of the power converter is ensured. In a power converter system, in order not to flow excess current generated in secondary windings of the doubly-fed generator into the power converter, a rectifier is connected in parallel to the power converter via a reactor, a DC link of the rectifier is connected to a DC link of the power converter, excess current flowing from the secondary windings is separately flowed at a reactor impedance ratio to reduce an amount of current flowing into the power converter, and a semiconductor switching element of an excess current generation arm of the power converter is set to an on-state.

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 fuel cell detection device according to the present invention includes: a cell block formed with a plurality of cells serially connected to each other; a voltage detection element for detecting voltages of the cells within the cell block; and another voltage detection element for detecting a voltage of the operating power source of the voltage detection element, where the operating power source of the voltage detection element is supplied from a voltage of the inside or both ends of the cell block, and the operating power source of another voltage detection element is supplied from a voltage of the outside of the cell block, the operating power source of another voltage detection element being less variable than the operating power source of the voltage detection element.

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: 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: 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 power generation apparatus equipped with an AC energization synchronous generator, when energization of a secondary winding starts to conduct connecting to the network of the AC energization synchronous generator to a network voltage, energization of the secondary winding starts at a fixed frequency and a slip frequency is calculated from a difference between a frequency of the network voltage and a resultant stator voltage frequency. Thereafter, energization starts at the calculated slip frequency and a voltage having a frequency generally coincident with the network frequency is output to the stator to incorporate the generator to the network. A phase is adjusted to make zero a phase difference when the rotation speed changes or the phases become different.

Abstract: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.

Abstract: A wind turbine generator system is equipped with a three phase generator connected to a shaft of a windmill, a converter connected to a stator of the generator, and an inverter connected to the converter and also to an electric power system. The system extracts a torsional vibration component of the shafting between the windmill and generator from the detected rotation speed of the generator, regulates the active component of the current command to the converter according to the vibration component, and controls so as to minimize the rotation speed variation of the generator.

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: A fuel cell unit of the present invention has, in a casing, a fuel cell stack in which plural fuel cells are stacked, monitoring means that detects and monitors voltage, temperature, and the like of the fuel cells, and voltage converting means that boosts output voltage of the fuel cell stack and outputs the boosted output voltage to the outside of the unit. The voltage converting means determines an optimum output current on the basis of states such as the voltage, temperature, and the like of the fuel cells that is output from the monitoring means, and increases or decreases the power generation current of the fuel cell stack.

Abstract: A wind turbine generator system is equipped with a three phase generator connected to a shaft of a windmill, a converter connected to a stator of the generator, and an inverter connected to the converter and also to an electric power system. The system extracts a torsional vibration component of the shafting between the windmill and generator from the detected rotation speed of the generator, regulates the active component of the current command to the converter according to the vibration component, and controls so as to minimize the rotation speed variation of the generator.

Abstract: A time zone when the operation pattern is obtained with a high learning convergence and a time zone when such an operation pattern cannot be obtained are set in advance. In the case where a significant difference develops between a target operation pattern and an actual load pattern, it is possible to accurately determine whether the operation is to be continued without changing the operation pattern or the operating conditions such as the hydrogen production amount should be changed in accordance with the actual load pattern. As a result, based on the scheduled operation with a predetermined operation pattern, the operation can be easily corrected in accordance with the complicated load change in home applications.

Abstract: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.

Abstract: An object of the present invention is to minimize the torsional vibration caused on the shafting of the wind turbine genarator system so as to operate the windmill stably. A wind turbine genarator system according to the present invention, equipped with a synchronous generator connected to the shaft of a windmill, converter connected to the stator of the synchronous generator, and inverter connected to the converter and also to an electric power system, extracts the torsional vibration component of the shafting between the windmill and synchronous generator from the detected rotation speed of the synchronous generator, regulates the active component of the current command to the converter according to the vibration component, and controls so as to minimize the rotation speed variation of the synchronous generator.

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: Because of the necessity of resolver for detecting a rotating position, which is very expensive, and noise suppression of the rotating position signal line on a doubly-fed machine, cost increase of the generator and reduced reliability due to possible failures are inevitable. In order to solve such problem, a generation system in the present invention is equipped with an exciter that estimates the slip frequency of the doubly-fed machine from each primary current I1 and voltage V1 and secondary current I2 and voltage V2 of the doubly-fed machine and excites the secondary of the doubly-fed machine at the estimated slip frequency.