关于110kV主变后备保护动作分析和整定计算的探索

在装有两台并列运行三圈变压器的变电站,如主变10 kV(或35 kV)侧保护CT至本侧母线处发生短路故障,故障变压器低压侧开关(或中压侧开关)跳闸后不能切除故障,或故障变压器低压侧开关(或中压侧开关)拒动不能隔离故障,将会造成全站失压.为此提出在主变10kV(或35kV)侧后备保护中设置一段方向由本侧母线指向变压器的复...

Investigation on the Operation Analysis And Setting Calculation of 110kV Main Transformer Backup Protection

In the substation with two parallel operating three-winding transformers, if the short-circuit fault between the 10kV (or 35kV) protection CT of the main transformer to the same side bus occurs, the switch on 10kV (or 35kV) trips and fault still keeps, or the switch refuses to trip and the fault can not be isolated, which will cause the whole substation to loss power. This paper puts forward to add the compound voltage lockout directional overcurrent protection in backup protection of main transformer 10kV (or 35kV) side and the direction pointing from the same side bus to the main transformer, and introduces the setting calculation principles for the overcurrent protection, which ensures that losing power scope is the smallest.