Analysis and Modification Measures of a Lightning Damage Accident of Main Transformer in Mining Area Power Grid
Chen Jinli · Insulators and Surge Arresters · 2015
According to the lightning damage accident of main transformer in tun-lan 110 k V substation, and in combination with the information of field investigation and laboratory test, the reason of the accident is discussed in the paper. Considering that the ground down lead of surge arrester is too long,the impulse grounding resistance of the substation is too high, the lightning waves intrusion substation without the effective restrictions of inlet lines protection is the main reason of the accident. The following targeted modification measures are put forward: Optimizing the substation grounding device, normalizing the length of grounding down lead of surge arrester, installing the Zinc Oxide lightning arrester on inlet lines towers, and testing the tower grounding device of the towers which installing the Zinc Oxide lightning arrester. Through the above measures, the hidden trouble of lightning protection in transformer substation has been eliminated, and the power supply reliability is greatly improved.