110kV变压器中性点间隙保护的配置与整定

Configuration and Setting of Neutral Point Clearance Protection for 110kV Transformers

计算分析某炼化变110kV主变压器中性点不接地时的过电压,根据国家电网公司和电力规程对变压器中性点保护的规定,拆除原有中性点仅为避雷器的保护形式,提出采用间隙保护与避雷器相互并联的中性点保护方式,并确定了间隙距离。通过继电保护定值的整定,保障了变压器在系统发生单相接地、非全相分合闸或雷电冲击时,均能安全稳定运行。

Through calculating the overvoltage of a 110 kV master transformer’s neutral non-grounding,the former protection of the neutral point equipped with lighting arrester only was dismantled in accordance with State Grid’s stipulation and the electricity regulations concerned and a neutral point protection scheme with the clearance protection and the lightning arrester in parallel was proposed and the clearance distance was determined.Through the setting of relay protection,the transformer can operate safely and stably in the case of single-phase grounding,non-full phase opening and closing or lightning impact.