China commissions first 126kV eco fast-switching fault limiter post short-circuit test
The overall current limiting effect time is 6.8 milliseconds, and the manual grounding short circuit verification test of the 126 kV environmentally friendly fast switching fault current limiter has been successfully completed! "At around 3:00 pm on April 14, 2025, as the on-site test leader of the 330 kV Dongdatan substation of Gansu Power Grid announced the test results, the 126 kV environmentally friendly fast switching fault current limiter developed by Nanrui Jibao, an executive director unit of the China Electricity Council, was successfully connected to the grid and put into operation, achieving its first engineering application.
With the rapid development of Gansu power grid in recent years, the level of 110 kV short-circuit current at Jinchangdong Datan substation has been continuously increasing, affecting the safe and stable operation of the regional 110 kV power grid, and corresponding governance measures need to be taken.
The complete set of 126 kV environmental protection fast switch type fault current limiter equipment consists of a fast circuit breaker, a current limiting reactor, and a fast circuit breaker control device. The core 126 kV fast circuit breaker is the first application of a single break vacuum arc extinguishing chamber in a 110 kV power grid for the fast switch series products. It uses high-voltage dry air to meet the external insulation requirements for the first time, is fluorine free and zero carbon, and requires maintenance free breaking. It can be applied in extremely cold areas below -40 degrees Celsius, meeting the green and environmental protection requirements of power equipment under the "dual carbon" target. The rated current is 3150 amperes, and the rated short-circuit breaking current is 50 kiloamperes. It adopts a phase separated electromagnetic repulsion operating mechanism, and the opening time is less than 1.5 milliseconds, which is only 1/20 of that of a conventional circuit breaker. The fully open breaking time is less than 15 milliseconds. In conjunction with the intelligent control and protection system, the 126 kV fast circuit breaker can not only be used for short-circuit current exceeding the standard, but also for transformer excitation surge suppression, voltage sag control, and rapid disconnection and grid connection of source grid load storage integrated power supply, improving the reliability of power grid operation.
