摘要
双馈感应电机(DFIG)与公共耦合点(PCC)间投入故障电流限制器(FCL)实现低电压穿越(LVRT)时,定子电压受FCL阻抗与网侧变流器(GSC)电流影响,无法设定定子电压,需要对DFIG与FCL整体建模以分析故障电流。基于恒定电流控制策略推导转子侧变流器(RSC)与GSC电流,提出DFIG故障电流的解析表达式。考虑到电压定向下定子相角振荡会导致dq轴恒定电流在xy轴下变化,不利于定子电流稳定,采用dq轴与xy轴相重合的定向方案。对比不同的RSC与GSC电流参考值、FCL阻抗值与切出时间下DFIG LVRT过程中的电磁转矩振荡,选择LVRT性能较好的一组控制参数。仿真结果表明,FCL阻抗取值受RSC与GSC电流参考值影响,且FCL阻抗越大,所取切出时间越短。
When FCL（Fault Current Limiter）is put in between DFIG（Doubly-Fed Induction Generator）and PCC（Point of Common Coupling）to achieve the function of LVRT（Low Voltage Ride Through）,the stator voltage cannot be set due to the influence of FCL impedance and GSC（Grid Side Converter）current,so a holistic model of DFIG and FCL is needed to analyze the fault current.The currents of RSC（Rotor Side Converter）and GSC are deduced based on constant current control strategy,and the analytical expression of DFIG fault current is proposed.Since the stator phase angle oscillation under voltage orientation will cause the constant currents of d-q reference frame change under x-y reference frame,which is unfavorable for the stabilization of stator current,the orientation scheme with coincidence of d-q reference frame and x-y reference frame is adopted.The electromagnetic torque oscillation in the process of DFIG LVRT is compared for different current references of RSC and GSC,FCL impedances and tripping time,and the control parameter set with better LVRT performance is selected.Simulative results show that the selection of FCL impedance is influenced by RSC and GSC current reference,and the selected tripping time becomes shorter along with the larger of FCL impedance.
出处
《电力自动化设备》
EI
CSCD
北大核心
2017年第11期8-13,21,共7页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(51277049)~~
