电压不对称故障下光伏逆变器低电压穿越技术  

Low Voltage Ride Through Technology of Photovoltaic Inverter under Voltage Asymmetric Fault

作　　者：王京保[1] 曾国宏[1] 荆龙[1] 

机构地区：[1]北京交通大学电气工程学院,北京100044

出　　处：《电气传动》2013年第12期24-27,共4页Electric Drive

摘　　要：在电网电压对称情况下,光伏并网逆变器在传统的双闭环控制方式下拥有良好的动态和稳态性能。在电网电压不对称情况下,不对称电压和不对称电流中存在负序分量,严重影响光伏并网逆变器输入电压及输出电流品质。根据同步旋转坐标变换和对称分量法,在瞬时功率分析的基础上,采用抑制交流侧负序电流的控制方案。考虑逆变器电流安全限值等问题,实现电网电压不对称故障下光伏并网逆变器的低电压穿越运行。在Matlab/Simulink中建立了光伏并网发电系统仿真模型,得到电网电压不对称故障下的仿真结果,验证了控制策略的有效性。Under grid voltage symmetrical case,grid-connected photovoltaic inverter has good dynamic and steadystate performance in traditional double closed-loop control mode.Under grid voltage asymmetrical case,negative sequence component existing in asymmetrical voltage and asymmetrical current seriously affects the quality of input voltage and output current of photovoltaic grid-connected inverter.According to the synchronous rotating coordinate transformation and the method of symmetrical components,a control scheme was adopted that aims to suppress negativesequence current of AC side based on the analysis of the instantaneous power.Considering problems such as inverter current safety limit,the proposed LVRT operation of grid-connected photovoltaic inverter can be effectively realized under grid voltage asymmetric fault.A simulation model of grid-connected PV systems was built in Matlab/Simulink,and the simulation results under grid voltage asymmetric fault prove the effectiveness of the control strategy.

关 键 词：光伏并网逆变器 不对称故障 正序、负序电流 瞬时功率分析 低电压穿越 

分 类 号：TM464[电气工程—电器]