The 10kV section I bus of 35kV Zhangwo substation has been charged without discharge. "On the morning of Aug 9, after nearly nine hours of continuous emergency repair, Zhang Ao, the leader of the first shift of substation maintenance in the substation maintenance center of Bozhou Power Supply Company, finished the on-site work and reported the progress in time.

In recent days, the maintenance personnel of Bozhou Power Supply Company found that there were discharge defects and obvious discharge sound in the back of the switchgear of 10kV 113, 114 and 115 in the 35kV Zhangwo substation during the summer special tour to meet the peak. The transient ground potential of the switchgear and the ultrasonic partial discharge detection confirmed that there were discharge defects in the bus bar chamber of the three side switch cabinets.

The 35kV Zhangwo substation is an important hub of the power grid in Niuji town, which undertakes the power supply task for more than 30,000 households in Niuji town and its surrounding areas. In order to reduce the impact on users' power consumption, the company plans to carry out emergency repair without power outage during the low power consumption period at night.

In order to ensure the smooth progress of "zero point emergency repair", the company's leaders in charge took the lead in organizing a special disposal meeting, comprehensively studying and judging the meeting, preparing the emergency repair plan and load transfer plan in detail, urgently allocating materials, conducting on-site investigation in advance, determining the time of emergency repair, and making preparations for all items of emergency repair.

"We determine the load transfer time according to the load curve of the lines that need to be cut off in recent days, and call a medium voltage generator tram to ensure reliable power supply for residents," Tian Zhenning, the special director of the transportation inspection department, said on the spot.

This emergency repair involves the operation inspection department, distribution network department, dispatching center, substation operation and maintenance center, substation maintenance center, Qiaocheng power supply branch and other departments. It needs to go through a series of processes, such as live access to power generation vehicles, load transfer, dispatching orders, switching operation, emergency repair and power transmission restoration.

At 2:03 am on Aug 9, the power outage task was completed, and the maintenance personnel carried out the emergency repair in an orderly manner according to the division of labor in advance. The emergency repair work is divided into three stages. The first stage is to inspect the insulation of 35kV section I bus switchgear one by one, identify the fault point, and remove the fault insulation and contact box. The second stage installation and replacement. In the third stage, the withstand voltage test of 10kV section I bus bar switchgear was carried out, and the overall inspection and acceptance were carried out to restore power transmission.

Although the work in the early morning was mentally tiring, the maintenance personnel did not complain and the work site was busy but not chaotic. "Although zero point repairs are arduous, it can achieve zero user perception. No matter how hard we work, it is still worth it," said Zhang Ao.

At present, during the critical period of the peak summer season, substation maintenance personnel will further increase their inspection efforts, timely grasp the operation status of substation equipment, comprehensively eliminate equipment hazards, improve the healthy operation level of equipment and ensure that residents have a cool summer and be worry free of electricity consumption.