基于风险理论的合闸过电压抑制方案评估方法研究OA

The circuit breaker closing resistance is an effective measure to restrain the power system closing operation overvoltage,and the line lightning arrester plays a backup protection role.However,with the shortening of transmission lines and the improvement lightning arresters,the line switching overvoltage has decreased.Meanwhile,the closing resistances have prominent disadvantages,including high cost and low reliability.There is a lack of quantitative assessment method about the economy and feasibility of the closing over-voltage suppression scheme.In this paper,the assessment method of closing overvoltage suppression scheme was proposed based on risk theory.The overvoltage simulation model along transmission lines was built.We present the comprehensive risk index considering flashover rate,fault rate and cost,and also make the quantitative assessment of the economy and feasibility of overvoltage suppression scheme.The overvoltage simulation and risk index calculation were realized in an actual 500 kV power grid,so as to study the feasibility of canceling circuit breaker closing resistor.It is verified that the proposed evaluation method can reasonably quantify the overvoltage suppression effect and the system risk,which can provide effective assessment for selection of overvoltage suppression scheme.