Research on measuring and controllable method of UHV AC power electronic CMOA by BOD self triggered mode

The power electronic controllable metal oxide arrester(CMOA, shortly) could make full use of the advantages of fast conduction speed of power electronic devices. It could not only limit the switching overvoltage, but also limit the lightning overvoltage in part of the long wave head time, so as to effectively protect the substation and line equipment. The measuring and controllable method directly determined the operation reliability and accuracy of power electronic controllable arrester, which need special research. This paper analyzed the feasibility of using measuring and controllable method based on system voltage sensor for CMOA. The method based on BOD self triggering mode was proposed, and the test model was designed. Simulation tests were carried out under power frequency voltage, switching impulse voltage and lightning impulse voltage to verify the feasibility and effectiveness of BOD self triggering mode. The test results showed that the self triggering mode based on BOD was feasible. The accuracy of measuring and controllable method based on BOD self triggering mode was mainly affected by the error of BOD breakdown voltage U BO , manufacturing error and voltage sharing rate deviation of thyristor voltage equalizing resistor MOR, aging performance of arrester resistor, leakage current caused by pollution of controllable arrester porcelain bushing, and so on. The influence could be controlled within the allowable range by reducing the long-term operation charge rate of lightning arrester. The measurement control method based on BOD self triggering mode could accurately control the power electronic switch of CMOA. The switch had simple structure and remarkable economic benefits.