Research On The Optimize Control Technologies Of The Running Quality Of Wind Turbine With Full-Power Converter

Wind energy plays an extremely important role in releasing the current energysources and environment crisis. In recent years, with increasing total installed capacity ineach country, and the proportion of wind power's share in electricity supply going higherand higher, maintaining the wind turbine system safe, reliable and effective operation inwind power farms has become the key research of wind power. Along with thedevelopment of the technology, and the continuously going down cost of converters,wind turbine with full-power converter, with its unique advantages, will have more andmore extensive use in the future. The following article, making the wind turbine withfull-power converter (squirrel cage induction generator and permanent magnetsynchronous generator) as the research subject, did the following research: optimal powercapturing control technology, wind turbines' protection and optimization controltechnology, generator's high effective and reliable operation technology.On the aspect of wind turbine's optimal power capturing control, variable stepclimbing for searching optimization method has been proposed, solving the problems inconstant step climbing searching method of optimization searching for a long time,inaccurately capturing optimal power and unstable rotation speed, etc. On the basis ofthis method, mixed control method was proposed, and combines the already known givenmethod and variable step method, solving the problem of capturing inaccurate optimalpower in already known method because the biased data provided by the factory,meanwhile revising the optimal power at real time.As for the wind turbines' safe operation under the condition of grid fault, a kind ofpredicting in advance protection and control strategy, proposed for symmetrical grid fault,combining the Crowbar circuit, realizes the wind turbine's effective low voltage ridingthrough. As for asymmetric grid fault, an improved double dq coordinate rotationtransformation control strategy was proposed, which can effectively maintain a constantDC voltage and a stable synchronization active power, according to guidelines providescorresponding wattles power, and reduces the total harmonic distortion variable of the current for grid.On the aspect of wind power generator ration speed signal extraction optimal control,a speed sensor-less vector control strategy, based on PLL technology, was proposed,solving the problem of adding integral element in obtaining electric displacement signal.In order to verify the research relation to mentioned above, a kind of software ofreduction ratio characteristic simulator of MW level wind turbine and maximum powerpoint tracking was designed. Meanwhile, a wind power simulator experimental platformwith double gearbox structure was set up, which extends the functions of wind powersimulation system, and make the research of MW level wind power technology realizablewith small power platform.