The first 252 kV bus tie fast circuit breaker is qualified for grid-connected applications

News from this newspaper at 15:00 on October 31, in the 220 kV Taole substation in Shizuishan, Ningxia, the first domestic bus-tie fast circuit breaker that had just been put into operation quickly disconnected within 12.6 milliseconds, limiting the short-circuit current to the network. within the range of the equipment. The single-phase instantaneous artificial grounding short-circuit test of the 252 kV bus-tie fast circuit breaker project of Taole Substation was successful, and it has the application conditions for hanging on the grid.

In recent years, Ningxia 750 kV double ring network has been formed. In order to solve the problem of excessive short-circuit current of the 220 kV substation bus in the northern power grid of Ningxia, Ningxia Electric Power Research Institute, Anhui Huidian Technology Co., Ltd. and Xi'an Jiaotong University developed a 252 kV bus-tie fast circuit breaker. and the Shizuishan Power Supply Company undertakes the "clinical trial" - running on the 220 kV Taole substation. Through artificial simulation of single-phase instantaneous grounding short circuit, it is verified that when a near-zone short-circuit fault occurs in a 220 kV AC system, the 252 kV bus tie fast circuit breaker can be quickly disconnected within 20 milliseconds, splitting the two bus bars of the substation to ensure that the All conventional circuit breakers open safely.

In order to ensure the smooth connection and safe operation of the new circuit breaker, Shizuishan Power Supply Company organized professionals to supervise the factory work of the bus tie quick circuit breaker in the whole process based on the structural principle and action logic of the bus tie quick circuit breaker, and compiled a formula that conforms to the actual situation on site. Complete the installation work in a safe and orderly manner. Shizuishan Power Supply Company has carefully formulated a test plan to minimize the safety risks brought by the test to the Shizuishan power grid, rationally arrange the operation mode of the power grid, communicate with surrounding key users and power plants in advance, strengthen operation monitoring and make emergency plans.

In the next step, the 252 kV bus-tie fast circuit breaker will be put into trial operation in Shizuishan power grid for one year. Shizuishan Power Supply Company will conduct special inspections, focus on monitoring the equipment, and standardize the operation records to continuously verify the effectiveness of the application of new technologies and equipment.