The Control Of 10KW Wind Turbine Generator

There is big distance between wind power big countries and China in field of grid wind power, and it becomes an urgent issue for our wind power industry to get independent technologies in its current transform system and control system. Taking permanent direct drive wind generating set as the object of study, this paper develops a research into its current transform system and control system and confirms that the converter has double PWM "back to back" full power current transform topological structure. According to the proposed control strategy and takes net side converter as an example, this paper designs hardware and software of the control system and proves the theory's correctness through established experiment platform.Firstly, current transformer is controlled though SVPWM technology, whose technique principle is introduced in the first place. The control target of full power converter system is given as following:Side converter works in condition of rectification; Rotating speed adjustment function of permanent magnet synchro generator will be fulfilled; Maximum power of blower will be traced and net side converter works in active contravariant to ensure wind generator set is paralleled in by unit power factor.Secondly, on basis of setting up mathematical model of bilateral converters, motor side converter adopts zero q-shaft current vector control method to control rotating speed of blower. Net side converter uses grid voltage directional control method to paralleled in unit power factor of wind generator set.Thirdly, main circuit of net side converter is made out. Considering the rapid following performance and anti-interference of direct voltage, we can make sure about the capacitance parameter of direct current stored energy. By using L-filter, AC side filtering inductance parameter is confirmed by rapid following performance of current cyclic and the suppression on ultraharmonics. Meanwhile, control circuits are designed include signal testing circuit for voltage and current, net frequency detection circuit, protecting circuit, communication circuit and man-machine interface circuit.Fourthly, we make software design for net side converter control system, propose its software structure and provide testing method of power grid phase sequence. Specific to the disadvantage of traditional phase lock loop, a software PLL is designed on basis of coordinate transformation. It can precisely lock power grid angle when three phase grid is unbalanced and also realizes coordinate transformation while converter decoupling control is proceed.Finally, experiment platform of net side converter is established to prove the control strategy and arithmetic carried out on converter. We can see from the result analysis that synchronization current and grid voltage share same frequency but have reversal phase, and unit power factor of wind power generator can be paralleled in grid. Voltage outer ring has small static error but have fast dynamic response. It fully proves the effectiveness and correctness of converter control strategy. Expected goals are reached.