Variable-speed Constant-frequency Wind-power Generation System
Abstract
The variable-speed and constant-frequency controlling system is a wind-power generation unit DCS controlling system, which is based on industrial controlling computer and digital signal processor (DSP),Its primary mission is to make the generator join in or cut off from the different sensors.(internal sensor of wind electrical machinery, transmitter of electrical network’s voltage and current).According to the date gathered, the computer program will automatically execute all controlling operation in the best and safest way. And the computer can real time monitor all the threshold parameters. The system can automatically collect and memory the performance date through forms and graphs. to invoke each sort of information and historical records, and through the entire Chinese-characterized interface between machine and humans, to make the user observe variable date and the condition of the system at the liquid-crystal display, adjusting the settings. For the power keyboard, the device for protection is located in the ground tower and that for measurment is placed on the tower. The system can also remote control the wind-power generating system in central controlling hall, using telephone line and the modem (or RS485). And the system is widely used for its low consumption. And convenient operation. Through the research and manufacture of this subject, the principle and circuit of the automatic system, part of the variable-speed and constant-frequency, for best using the wind power are analyzed, the performance and energy converting characteristics are discussed, finally its fine application in the generation of renewable energy electric is forecast. Through the simulation, it is confirmed that, the wind power simulated by electrical machinery of direct current can afford the variable-speed and-constant-frequency wind power system, which is composed by double-fed electrical machinery the feasibility of performance at the best power trace. Then, the control of current is proved, realizing variable-speed and constant-frequency performance of the system. Its three-phase stator winding is connected to the electrical networks by the direct-alternating-direct bi-directional converter which is computer by IGBT. Meanwhile, the paper outlines the domestic and foreign developing of the wind-power generation and its present situation, pointing out the developing tendency and researching direction.
Keywords: changing speed constant frequency; wind power generator；controlling system
