摘要
非隔离型光伏并网逆变器在低电压穿越(LVRT)期间会出现较大的隐性漏电流,危及设备及人身安全。为此提出一种带直流旁路的逆变器拓扑结构,可以消除漏电流的危害。为了提高所提出的无漏电流光伏逆变器在LVRT期间运行的可靠性,光伏逆变器在电网故障时采用恒电流幅值策略,利用光伏系统本身无功优势补偿并网点电压跌落,待电网恢复正常后系统切换为单位功率因数运行。实验结果证明了所提方案的有效性。
Larger hidden leakage currrent occurs in isolated grid-connected photovoltaic inverter during low voltage ride through （LVRT） will threaten the equipment and individuals.An inverter with DC bypass topology which can eliminate leakage currrent is proposed.In order to improve the reliability of the proposed photovohaic inverter without leakage current during LVRT, the constant current strategy for reactive power compensation is adopted to compensate the sag voltage at point of common coupling.When grid faults disappear,photovohaic system should be switched to operate at unity power factor.The effectiveness of the proposed scheme is proved by the experimental result.
出处
《电力电子技术》
CSCD
北大核心
2015年第8期6-8,共3页
Power Electronics
基金
国家自然科学基金(51277024)~~
关键词
逆变器
低电压穿越
漏电流
inverter
low voltage ride through
leakage current
