在直驱风力发电系统控制中,网侧变流器采用电网电压定向矢量控制策略,因此快速而准确地检测电网基波电压的大小和相位在网侧变流器同步化设计中是很关键的.介绍基于对称分量法的同步坐标系锁相方法和双同步坐标系解耦锁相方法:研究在不平衡电网电压下变流器中使用的2种不同电流控制器的性能,这2种控制器是基于正参考坐标系和负序分量前馈控制(VCCF)的电流控制器和基于正负序参考坐标系(DVCC)的双电流控制器.仿真和实验结果表明;在电网电压出现不平衡时,精确地检测电网电压基波的正、负序分量并且使用正负序旋转坐标系下双电流控制策略,在网侧变流器控制中起到了一个很关键的作用.%In the grid-side converter control of a direct-drive wind power generation system, grid-voltage-oriented vector control strategy is used. The fast and precise detection of amplitudes and phases of fundamental-frequency voltage components is a crucial issue in the synchronization design of a grid-side converter. Two phase-locked methods, namely, single synchronous reference frame method based on instantaneous symmetrical component method and double synchronous reference frame method, were proposed. The performances of two different current controllers, I.e. VCCF-based controllers and DVCC-based controllers, used in the grid-side converter under unbalanced voltage conditions were also investigated. Simulation and experimental results show that accurate detection of the fundamental-frequency positive- and negative-sequence voltage components of utility voltages and double current loop control strategy under positive- and negative-sequence rotating frame play a key role in controlling power converter under voltage unbalance conditions.
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