特高压换流站单相短路电流抑制措施及对电网可靠性的影响分析

Analysis of Suppression Measures on Single － phase Short － circuit Current in UHVDC Converter Station and Its Impacts on Power Grid Ｒeliability

摘要:

针对宜宾、复龙换流站单相短路电流超过开关遮断水平的问题，分析其产生的原因，根据近区电网布局和规 划，提出了限制近区火电开机、主变压器中性点经小电抗接地、线路加装串联电抗器等抑制单相短路电流的措施。通 过分析比较不同措施对换流站单相短路电流的限制效果，以及对电网设备运行和供电可靠性的影响，给出可行的降 低换流站 500 kV 侧单相短路电流的措施建议。

Abstract:

Aiming at the issues that single － phase short － circuit current at the 500 kV side of Yibin and Fulong converter stations exceeds the breaking capacity of breaker，the reasons are analyzed and the measures are put forward to reduce the single － phase short － circuit current，including limiting the output of thermal power near field，main transformer neutral grounding by small reactance and adding series reactors in 500 kV lines． The limiting effects on single － phase short － circuit current and the impacts on power grid equipment operation and power supply reliability are compared by different measures． The suggestions for reducing single － phase short － circuit current at 500 kV bus of UHVDC converter station are given．