逆变侧换流变阀侧连接线单相接地动作策略分析

Analysis of Fault Clearing Actions Under Single Phase to Ground Fault of Lines Connecting Transformer and Inverter Valve

高压直流输电逆变侧换流变阀侧连接线单相接地故障动作策略投旁通对后,巨大的短路电流会流经阀组。分析这种接地故障动作策略投旁通对后的阀组电流流向及大小。对比分析投旁通对和不投旁通对阀组的过流情况。提出优化的动作处理策略,使得在任何情况下逆变侧换流变阀侧连接线单相接地故障的保护动作处理过程中,不会造成阀组流过大的电流,避免阀组损坏。

During the grounding fault of the line connecting the transformer and the inverter valve,a huge fault current will flow through valve group after setting by-pass-pair（BPP）within the fault clearing actions.The current value and direction of valve group are analyzed for this fault case.Over-current of valve group with setting BPP and without setting BPP are compared.This paper proposes an optimal fault clearing action for this grounding fault.This optimal fault clearing action can be used to avoid the huge over-current passing through the valve group during fault clearing process.It also helps to avoid valve group damage in the fault clearing process.