电网电压不平衡条件下混合无功补偿系统分层协调控制策略

为实现低压配电网低成本大容量动态连续无功补偿,提出了一种晶闸管投切电容器(TSC)与静止无功发生器(SVG)协同运行的混合无功补偿系统。系统综合了TSC低成本大容量的无功补偿和SVG动态连续无功补偿的优点。在分析其基本原理的基础上,提出混合无功补偿系统分层协调控制策略,消除TSC与SVG由于响应速度的差别对其混合无功补偿性能的影响。针对混合无功补偿系统在电网电压不平衡条件下的安全运行问题,研究了SVG的正负序双环叠加控制策略,使其在具有动态无功补偿性能的同时能抑制一定程度的不平衡电压,保证系统的安全稳定运行。最后,仿真验证了所提控制策略的正确性。

Hierarchical Coordinated Control Strategy of Hybrid Reactive Compensation System under Unbalanced Grid Voltage

In order to realize reactive power compensation of low voltage distribution network with low cost, large capacity and dynamic continuity, a hybrid reactive compensation system based on thyristor switched capacitor (TSC) and static var generator (SVG) is proposed. The advantages of TSC low cost and large capacity reactive power compensation and SVG dynamic continuous reactive power compensation are combined in this system. Based on the analysis of its basic principles, a hierarchical coordination control strategy is proposed to eliminate the influence of TSC and SVG on its hybrid reactive compensation performance because of the differences in response speed. Aiming at the safe operation of hybrid reactive compensation system under unbalance grid voltage, the control strategy of double-loop superposition of positive and negative sequence of SVG is studied. So that a certain degree of unbalance voltage can be suppressed, at the same time with dynamic reactive power compensation performance, to ensure the safe and stable operation of the system. Finally, the correctness of the proposed control strategy is verified through simulation.