基于d-q坐标系的单相链式STATCOM直流电压平衡控制策略  

A Balance Control Strategy of DC-Link Voltages for Single Phase Cascaded STATCOM Based on d-q Coordinates

作　　者：孙毅超[1] 赵剑锋[1] 季振东[1] 姚晓君[1] 

机构地区：[1]东南大学电气工程学院,江苏省南京市210096

出　　处：《电网技术》2013年第9期2500-2506,共7页Power System Technology

基　　金：江苏省产学研前瞻性联合研究项目(BY2011156)的资助

摘　　要：直流侧电压平衡是单相链式STATCOM能够安全、可靠运行的前提,而各H桥之间有功功率损耗的差异是造成直流侧电压不平衡的根本原因。建立了单相链式STATCOM在d-q旋转坐标系下的数学模型,基于瞬时功率理论分析了引起直流电压不平衡的原因,并设计了由前馈解耦电流内环、电压均值外环和电压平衡外环组成的三环控制策略。与在a-b-c静止坐标系下的控制策略相比,该方法不仅实现了网侧电流的无静差控制,同时更便于直流侧电压平衡环节的实现。仿真与实验均验证了该方法的有效性。DC-link voltage balance is regarded as the presupposition to ensure the secure and reliable operation of single-phase cascaded STATCOM, and the differences of active power losses among H-bridges are the basic reason leading to unbalanced DC-link voltages. A mathematical model of single-phase cascaded STATCOM in d-q coordinates is established and based on instantaneous power theory the reason causing unbalanced DC-link voltages is analyzed, and a three-loop control strategy composed of feed-forward decoupling current inner loop, average voltage outer loop and balanced voltage outer loop is designed. Comparing with the control strategy in a-b-c rest frame, the proposed control strategy not only achieves the grid-side current control without steady-state error but also is more convenient to realize DC-link voltage balance. The effectiveness of the proposed method is validated by results of simulation and experiments.

关 键 词：单相链式STATCOM d-q坐标系 直流电压平衡 虚拟三相法 

分 类 号：TM46[电气工程—电器]