星形链式STATCOM不对称负荷补偿策略

摘要

The star-connected cascade circuit static synchronous compensator(STATCOM) is subjected to the constraints of ungrounded neutral point that the sum of three phase output currents is restricted to zero.The interphase active power and DC voltage can be balanced by outputting zero-sequence voltage when the STATCOM generating negativesequence current in order to compensate the unbalanced load.The mathematical expression of zero-sequence voltage is deduced.Combining with the balance strategy of DC voltage,an unbalance current compensation strategy is proposed for star-connected cascade circuit STATCOM by decoupling current control.Simulation and experimental results verify the feasibility and validity of the presented compensation method.%星形链式静止同步补偿器(STATCOM)受中性点的约束,三相输出电流之和必须为零.STATCOM在输出负序电流补偿系统不对称负荷时,可通过输出零序电压来维持STATCOM相间有功和直流电压的平衡.推导星形链式STATCOM补偿不平衡电流所需输出零序电压的数学表达式,结合相间直流电压平衡策略,给出电流解耦控制下星形链式STATCOM不对称负荷补偿策略.仿真和实验验证了所提方法的有效性和可行性.