不对称故障条件下并网光伏逆变器峰值电流抑制策略  

Control strategy to suppress peak current for grid-connected photovoltaic inverter under unbalanced voltage sags

作　　者：杨超颖 王金浩 杨赟磊 杜慧杰 徐永海 曹炜 YANG Chaoying;WANG Jinhao;YANG Yunlei;DU Huijie;XU Yonghai;CAO Wei(State Grid Electric Power Research Institute of Shanxi Electric Power Company,Taiyuan 030001,China;State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Beijing 102206,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 [2]新能源电力系统国家重点实验室(华北电力大学),北京102206

出　　处：《电力系统保护与控制》2018年第16期103-111,共9页Power System Protection and Control

基　　金：国家自然科学基金资助项目(51277069)~~

摘　　要：不对称故障在电网实际运行过程中时有发生,其导致的输出电流峰值较大的问题严重影响了光伏发电系统的可靠运行。首先对不对称故障条件下并网光伏逆变器输出电流峰值过大的机理进行了分析,进而提出了一种考虑输出电流峰值的参考电流算法,在已有参考电流算法中加入多个调节参数,能够对输出电流峰值和功率波动进行调节。在所提出改进参考电流算法基础上,提出了一种有功无功协调控制策略,有效解决了不对称故障条件下并网光伏逆变器的过流问题,拓展了光伏系统的有功输出能力。通过在PSCAD/EMTDC中建立仿真模型验证了所提出控制策略的正确性。Unbalanced voltage sags often occur during actual power grid operations,causing problem of excessing output peak current,which significantly affects the reliable operation of power grid.This paper first analyzes the mechanism of excessing peak current of grid-connected photovoltaic inverter under unbalanced voltage sags,then a reference current algorithm which takes output peak current into consideration is proposed,adding several adjusting parameters based on the existing reference current algorithm.The reference current algorithm can adjust peak current and power fluctuations.Based on the improved reference current algorithm,an active and reactive coordinate control strategy is proposed,the control strategy effectively solves the overcurrent problem under unbalanced voltage conditions,and expands the output active power of PV system.The simulation models in PSCAD/EMTDC are established to validate the proposed control strategy.

关 键 词：光伏逆变器 不对称故障 峰值电流 功率波动 

分 类 号：TM464[电气工程—电器]