电网电压不平衡条件下光伏并网逆变器的控制策略  

Study on Control Strategy of Photovoltaic Grid-connected Inverter under Unbalanced Grid Voltage

作　　者：王楠 刘星廷 王海旗 WANG Nan;LIU Xingting;WANG Haiqi(Electric Power Research Institute of State Grid Shanxi Electric Power Company,Taiyuan,Shanxi 030001,China)

机构地区：[1]国网山西省电力公司电力科学研究院,山西太原030001

出　　处：《山西电力》2022年第5期52-57,共6页Shanxi Electric Power

摘　　要：在传统单同步参考系锁相环的基础上,提出了解耦双同步参考坐标系锁相环,该种结构的锁相环实现了电网电压不平衡情况下准确的电网同步并分离出电网电压正负序分量。根据建立的数学模型以及瞬时功率与并网电流正负序分量之间的关系,提出以抑制并网电流负序分量为控制目标的控制策略,通过仿真分析发现采用该控制策略后,并网电流波形质量良好,谐波畸变率远低于并网标准要求,可以实现系统的安全稳定并网。Based on the traditional single synchronous reference system phase-locked loop,a decoupled double synchronous reference coordinate system phase-locked loop is put forward. The phase-locked loop of this structure can realize accurate grid synchronization and separate the positive and negative sequence components of grid voltage when the grid voltage is not balanced.Finally,according to the established mathematical model and the relationship between the instantaneous power and the positive and negative sequence components of the grid-connected current,a control strategy designed to restrain the negative sequence components of the grid-connected current is proposed. Through the simulation analysis,it is found that,after this control strategy is adopted,the waveform quality of the grid-connected current is good,the harmonic distortion rate is far lower than the requirements of the grid-connected standard,and the safe and stable grid connection of the system can be realized.

关 键 词：电网电压不平衡 光伏 逆变器 并网电流 正序分量 负序分量 

分 类 号：TM464[电气工程—电器]