Development of controllable metal oxide surge arrester with trigger switch for 500kV AC power system

Abstract

In order to meet the requirement of deeply limiting the operating overvoltage level of a 500 kV AC power system, a controllable metal oxide surge arrester with a trigger switch was developed. The key technical parameters of the arrester, such as rated voltage, reference voltage, insulation withstand, partial discharge, radio interference voltage, and residual voltage, were introduced. The prototype structures of the arrester body, such as the fixed part, the controlled part, and the gap switch, were designed, and the test verification work was carried out. The research results show that the DC 4mA reference voltage of the fixed part and the controlled part of the arrester body is 462.2kV and 180.2kV, respectively. The partial discharge is not more than 2.56pC, and the radio interference voltage is 195.7μV. The operating impulse residual voltage of the lightning arrester body at 15kA is 776.5kV. The external insulation of the fixed part has passed the lightning impulse test with an amplitude of 685kV, 650kV operating impulse test, and 452kV power frequency voltage test. At the same time, it has undergone two times the 4/10μs waveform with an amplitude of 105kA. The gap switch can effectively operate and achieve reliable coordination with the arrester body. All experimental results indicate that the performance indicators of the controllable arrester developed fully meet the technical requirements and meet the conditions for grid operation.