220kV变压器中性点间隙过电压保护与中性点间隙距离的配合分析

The analysis with gap overltage protection and protection gap of 220kV transformer neutral point

本文根据电压相量分析得出变压器实际运行时中性点零序电压的取值范围,再根据零序电压取值,计算变压器中性点间隙过电压保护整定值。继电保护采集到的中性点间隙电压、电流值达到整定值则可靠动作。同时根据零序电压取值,粗略的计算出中性点保护间隙距离,在系统发生单相接地时保护间隙不动作,在系统局部失地中性点过电压危及中性点绝缘安全的情况下可靠动作。通过继电保护、中性点间隙保护和中性点保护间隙的配合,保障变压器安全稳定运行。

In this paper, according to the voltage vector analysis of the actual operation of the transformer neutral zero sequence voltage range. According to the zero sequence voltage value, calculate the transformer neutral point over-voltage protection set value, the relay protection reliable action, jump circuit breaker. The transformer to exit the operation. And according to the value of zero sequence voltage, a rough calculation of the neutral point to protect the gap distance. In the system occurs when the single-phase ground protection gap is not reliable breakdown, in the system of local ground failure over-voltage endanger the safety of the neutral point of the case, the protection gap and reliable breakdown.