摘要
大规模风电经固定串补线路送出时,由于变流器与固定串补之间的相互作用,使双馈风电机组(DFIG)可能会存在一种新的次同步谐振(SSR)问题,称为次同步控制相互作用(SSCI)。提出反馈线性化控制策略,并将之应用于DFIG转子侧变流器和网侧变流器控制回路以抑制SSCI。首先对系统的反馈线性化条件进行验证,再选取合适的坐标变换,在保证系统零动态稳定的前提下求得非线性状态反馈规律。在MATLAB/Simulink下的仿真结果表明:与参数已整定的比例-积分控制策略相比,反馈线性化控制策略能够有效抑制SSCI,使DFIG在不同串补度和风速下都能保持稳定运行,且不影响DFIG的故障穿越能力。
A nonlinear controller based on feedback linearization technique was proposed to mitigate sub-synchronous control interaction(SSCI) in series-compensated doubly fed induction generator(DFIG). The feedback linearization controller was developed for rotor side converter(RSC) and grid side converter(GSC) through four necessary steps, i.e., assessment of the feedback linearizability, coordinate transformation, feedback linearization, and derivation of control laws. A DFIG-based wind farm adapted from the IEEE first benchmark model was utilized to evaluate the performance of the designed controller at varied wind speeds and compensation levels, and the capability of the proposed controller in mitigating SSCI was compared to a well-tuned proportional-integral(PI) controller. The simulation results demonstrated the superior damping performance of the designed controller.
引文
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