链式D-STATCOM的无源性控制

Passivity-based Control of Cascade D-STATCOM

配电网静止同步补偿器(distribution static synchronous compensator,D-STATCOM)由于其突出性能已被证明是配电网无功动态调节的有效手段,然而链式结构D-STATCOM每一相都由多个H桥逆变单元级联而成,是一个非线性多变量、强耦合的系统,难以同时实现无功电流与直流电压稳定均衡的控制。经过等效电路变换,建立单个H桥逆变单元的控制电路模型;基于无源性控制理论,设计无源性控制率,确保了对指令电流的渐进跟踪;通过给定指令电流,实现了链式D-STATCOM的无功电流的控制和直流电压稳定的控制;利用H桥逆变单元之间的能量交换实现了直流电压的均衡控制。仿真以及10 kV、±5 Mvar工程实际应用表明,此控制算法能够在实现无功电流控制的同时实现直流电压的稳定与均衡控制,且稳态特性好、动态响应快、算法实现简单、鲁棒性强,具有很强的工程实用价值,为链式D-STATCOM的研究、发展和产业化提供了基本保障和良好的平台。

To regulate the reactive power into power grid,the distribution static synchronous compensator（D-STATCOM） has been considered as one of the most valid methods due to its salient features.Cascade D-STATCOM,constructed by cascading several identical H-bridge（single-phase full bridge） inverters,is a strong-coupled and multiple variable nonlinear system,which makes it is very difficult to simultaneously realize the reactive current,dc voltage stability and balancing control.This paper built up the passivity-based control model of single H-bridge module,and then realized the reactive current and dc voltage stability control of cascade D-STATCOM based on this.Dc voltage balancing control was realized based on the power exchange among H-bridge modules.The validity and feasibility of this control strategy is verified by simulation results,and has been used on practical engineering of ±5Mvar,10kV D-STATCOM.Based on this,a basic insurance and good platform is provided for the study and development of cascade D-STATCOM.