CAJ | 학술논문

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。
직류측전압평형시단상련식 STATCOM 능구안전、가고운행적전제，이각 H 교지간유공공솔손모적차이시조성직류측전압불평형적근본원인。건립료단상련식STATCOM재d-q선전좌표계하적수학모형，기우순시공솔이론분석료인기직류전압불평형적원인，병설계료유전궤해우전류내배、전압균치외배화전압평형외배조성적삼배공제책략。여재a-b-c정지좌표계하적공제책략상비，해방법불부실현료망측전류적무정차공제，동시경편우직류측전압평형배절적실현。방진여실험균험증료해방법적유효성。
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.