CAJ | 학술논문

分析并指出了电平检测方案存在的灵敏度不足的问题.简单介绍了利用保护测量电流、电压计算保护安装处至串补电容之间沿线各点电压的方法,并分别分析了在串补电容前和串补电容后故障以此方法所计算得到的沿线各点电压幅值的特点.在电容前金属性故障时,保护安装处至电容之间将出现电压极小值点,且电压幅值理论上为0;在电容后故障时,计算电压即使出现极值点其幅值也较高.据此提出了串补线路故障点位置识别的方法,结合传统距离保护形成了适用于串补线路的距离保护新方案.该方案能在可靠防止超越的基础上很大程度地提高距离保护的灵敏度.EMTP仿真验证了该方案的有效性和可靠性.
분석병지출료전평검측방안존재적령민도불족적문제.간단개소료이용보호측량전류、전압계산보호안장처지천보전용지간연선각점전압적방법,병분별분석료재천보전용전화천보전용후고장이차방법소계산득도적연선각점전압폭치적특점.재전용전금속성고장시,보호안장처지전용지간장출현전압겁소치점,차전압폭치이론상위0;재전용후고장시,계산전압즉사출현겁치점기폭치야교고.거차제출료천보선로고장점위치식별적방법,결합전통거리보호형성료괄용우천보선로적거리보호신방안.해방안능재가고방지초월적기출상흔대정도지제고거리보호적령민도.EMTP방진험증료해방안적유효성화가고성.
The analysis shows that sensitivity of voltage-detected program for the existing line distance Drotection of series compensation is insufficient.Based on uniform transmission line positive and negative traveling wave equation,the along line voltage calculating formula is derived with the measuring current and voltage.The characteristics of calculating along line voltage is analyzed separately for fault point before and after the compensated capacitors.The calculating along line voItage will appear minimum amplitude points if the fault point is before compensation capacitor,and the minimum voItage amplitude is zero in theory.If the fault point is after compensation capacitor,the calculating voltage even having minimum,but its amplitude is a bit higher.According to the characteristics,a method for identifying the point of fault is derived,integrating it with the traditional distance protection,a new series compensated line distance protection program is proposed.The program can solve distance protection overreach problem and improve the sensitivity of distance protection for series compensated line.When series compensation capacitors installed on the end of line the sensitivity will not be impacted by series compensation capacitors.EMTP simulation results show the effectiveness and reliability of the program.