摘要
针对辽宁电网一起220 kV变压器短路事故,根据系统短路故障情况,利用序网络法建立系统三序网络模型,从而求出变压器二次绕组的短路零序电流。计算表明,变压器二次绕组零序电流过大是造成此次事故的主要原因,零序阻抗小于正序阻抗将使单相短路电流大于三相短路电流,给设备带来更大的损坏,并根据此次短路事故提出了反事故措施。
For a short circuit fault of 220 kV transformer in Liaoning power system, three sequence networks are modeled by means of sequence network method according to the short circuit fault. Then, the zero-sequence current in the secondary windings of the trans- former is gained. The calculation results indicated that the main cause to this fault is due to zero-sequence current in the secondary of＇ the transformer which is much larger than the rated value. The transformer is inclined to be damaged if zero-sequence impedance smal- ler than positive-sequence impedance. Finally, some measures to prevent the fault are proposed based on this short circuit fault.
出处
《东北电力技术》
2012年第9期32-34,共3页
Northeast Electric Power Technology
关键词
单相短路
变压器
序网络
零序电流
二次绕组
Single phase short circuit
Transformer
Sequence network
Zero-sequence current
Secondary winding
