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.
出处
《电网技术》
EI
CSCD
北大核心
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
