Hitachi, Ltd.

Fuji Heavy Industries Ltd.

Shinya Oohara

Motoo Futami

Masaya Ichinose

Mitsugu Matsutake

Kazuhiro Imaie

Tadashi Sodeyama

Shoji Fukuda

Takashi Shiraishi

Shigeo Yoshida

Takeyuki Itabashi

Kazumasa Ide

Shuji Katoh

Hiromitsu Sakai

Shigenori Inoue

Kazumi Fujii

Yasuhiro Imazu

Akira Kikuchi

Junji Tamura

Junichi Sugino

Tohru Yoshihara

Kazuya Tsutsumi

Efrain Eduardo Tamayo Ruiz

Hajime Komiyama

Chia-Tse Lee

Conventionally, optimum introduction assistance for devices including a FACTS device and a storage adapted to changes in impedance and a transmission capacity involved in an increase of renewable energy power supplies has not been achieved. Therefore, in order to solve the problem, the present invention provides a power system equipment introduction assistance device that calculates an introduction point of power system equipment coupled to a power system, the introduction assistance device including a calculating unit configured to calculate, on the basis of predetermined system information and information concerning the power system equipment scheduled to be introduced, a characteristic of the power system affecting the power system during the introduction of the power system equipment and calculate the introduction point of the power system equipment from a predetermined evaluation index related to the characteristic of the power system.

Power system equipment introduction assistance device and method

A pitch controller, uninterruptible power supply, and rotational speed detector are disposed in the rotor in a wind turbine. When a slip ring failure or wire breakage occurs, the pitch controller internally creates a pitch angle command so as to control the pitch angle.

Wind turbine and operating method thereof

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.

Wind power generation system and operation method thereof

A wind power generation system temporarily stops a power converter when a system disturbance occurs, and reactivates the power converter after detecting a solution of the problem of an influence (overcurrent of a stator, direct current component of a stator, overcurrent of a rotor, etc.) of a fault occurring in a doubly-fed generator during a system fault. During a system fault, a reactive current can be safely output from a doubly-fed generator to an electric power system without destroying equipment of the wind power generation system.

Wind power generation system and method of controlling power converter

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 &#x3b1;(t) varying with time is estimated based on fluctuating component &#x394;P of the active power P generated by the distributed generation and the voltage fluctuating component &#x394;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=&#x2212;&#x3b1;P or Q=&#x2212;&#x3b1;&#x394;P, to thereby suppresses only the voltage fluctuation of the power system attributable to the distributed generation.

Distributed generation system and power system stabilizing method

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.

Power generation apparatus using AC energization synchronous generator and method of controlling the same

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.

Wind power generation system

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.

Hydrogen production system using wind turbine generator

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.

Variable speed wind power generation system

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.

Wind power generation apparatus, wind power generation system and power system control apparatus

Wind power generation system and operating method thereof

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.

Power converter for doubly-fed power generator system

A power generation apparatus and method includes an AC energization synchronous generator, a switching device for connecting to a network disposed on a stator side of the AC energization synchronous generator, an energizing device for applying a variable frequency AC to a secondary winding of the AC energization synchronous generator, and a first voltage detection unit for detecting 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.

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.

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Hitachi, Japan

Shinya Oohara