改进型STATCOM控制策略研究

Control Strategy for Improved STATCOM

非线性负载与不平衡负载广泛存在于配电网中,一般补偿装置无法满足补偿需求,为此提出一种改进型STATCOM的控制策略。该策略以无功补偿为主、指定次谐波电流和基波负序补偿为辅,对负载电流进行检测,将检测到的电流通过PI控制器,使得STATCOM的补偿电流能够精确跟踪无功、谐波和基波负序指令电流。通过电压空间矢量调制实现对无功电流、指定次谐波电流、基波负序电流的补偿。PSCAD仿真结果表明,该策略完成了对配电网电能质量问题综合治理的目标。

Nonlinear and unbalanced loads widely exist in distribution network that general compensation devices cannot meet the demands, and the control strategy for improved STATCOM is put forward. The control strategy is mainly based on reactive power compensation with selective harmonic current and fundamental negative sequence current compensation also. First, the load current is detected by the PI controller, which makes the compensation current of STATCOM can track the reactive power, harmonic and negative sequence current. The reactive current, selective harmonic current and fundamental negative sequence current is compensated using SVPWM. The control strategy achieves the target of comprehensive management for the power quality of distribution network. PSCAD simulation results show the feasibility and superiority of the control strategy.