STATCOM相间直流电压平衡控制研究  

Analysis on DC voltage balance control between three phases for STATCOM

作　　者：邢超[1,2] 车延博 李胜男[2] 奚鑫泽 刘明群 XING Chao;CHE Yan-bo;LI Sheng-nan;XI Xin-ze;LIU Ming-qun(Key Laboratory of Smart Grid of Ministry of Education,Tianjin University,Tianjin 300354,China;Yunnan Electric Power Research Institute,Yunnan Power Grid Co.,Ltd,Kunming 650217,China)

机构地区：[1]天津大学智能电网教育部重点实验室,天津300354 [2]云南电网有限责任公司电力科学研究院,昆明650217

出　　处：《电机与控制学报》2020年第12期9-16,共8页Electric Machines and Control

基　　金：国家自然科学基金资助项目(51707026);国家重点研发计划资助(2016YFB0900200)。

摘　　要：维持相间直流电压平衡是链式STATCOM控制的关键之一。由于H桥单元并联损耗、开关损耗、调制比和脉冲延时等存在差异,链式STATCOM三相之间存在直流电压不平衡的问题。为此在现有零序电压注入方法的基础上,通过推导链式STATCOM输出功率关系,提出一种简单的零序电压的计算方法。同时考虑到电网不对称时,电压中的负序分量导致的相间直流电压不平衡波动,提出一种功率前馈的控制方法,该方法实时计算出负序电压所产生的不平衡功率并将其前馈,有效抑制不对称时三相之间的不平衡功率。仿真和实验结果验证了所提控制方法的有效性。Maintaining the DC voltage balance between three phases is one of the keys to cascaded STATCOM.Due to the difference in parallel loss,switching loss,modulation ratio and pulse delay of the H-bridge unit,there is a problem of DC voltage imbalance between the three phases of cascaded STATCOM.To solve this problem,a simple zero-sequence voltage calculation method is proposed by deriving the output power relationship of cascaded STATCOM based on the existing zero-sequence voltage injection method.Meanwhile,considering the asymmetry of the power grid,the negative sequence component in the voltage will cause DC voltage unbalanced fluctuation of the phases,a power feedforward control method is proposed.The method calculates the unbalanced power generated by the negative sequence voltage in real time and feeds it forward,effectively suppressing the unbalanced power between the three phases during asymmetry.Simulation and experimental results verify the effectiveness of the proposed control method.

关 键 词：链式STATCOM 电压平衡 功率前馈 瞬时对称分量 不平衡功率 负序电压 

分 类 号：TM761[电气工程—电力系统及自动化]