灵州换流站交流滤波器跳闸导致直流功率回降原因分析

Cause Analysis of DC Power Drop Caused by Tripping of AC Filter at Lingzhou Convertor Station

交流滤波器、断路器及控制保护设备作为换流站的主要设备,其运行状态直接影响到直流系统的安全运行,为了提高交流滤波器、断路器的可靠性,文章对某换流站交流滤波器、断路器的故障原因进行了分析。通过对断路器气体成分分析、故障波形分析、常规试验数据分析和解体检查等方法,判断断路器内部绝缘筒、合闸电阻存在质量缺陷,伴随着系统运行中交流滤波器频繁投切使断路器主断口绝缘水平不断下降产生闪络放电故障,又由于 BP11/13 交流滤波器电容器塔支柱绝缘子存在设计缺陷,断路器故障同时产生过电压造成多组 BP11/13 交流滤波器跳闸,造成绝对最小滤波器不满足导致直流功率回降。最后,针对故障原因提出对应的处理措施,消除了直流系统运行中的隐患。

The operation status of AC filter,circuit breaker and control & protection device,as the main equipment of converter station,have direct effect on the safe operation of DC system. For improving reli ability of AC filter and circuit breaker,in this paper,the cause of fault for the AC filter and circuit breaker at certain converter station is analyzed. The quality defects in the inner insulation tube and the closing re sistor of the circuit breaker is judged by such methods as analysis of gas composition,fault waveform,con ventional test data and disassembling inspection. The flashover discharge fault is generated due to continu ous reduction of insulation level across open contacts with frequent switching of AC filter during the opera tion. Many groups of BP11/13 AC filter are tripped due to overvoltage of the fault of the circuit breaker be cause of the design in the support insulator of BP11/13AC filter capacitor tower;causing the absolute min imum filter cannot meet requirement and leading to DC power reduction. Finally,the corresponding treat ment measures for the cause of the fault so to eliminate the hidden danger of the DC system in theoperation.