Research On The Ion Migration Of 500kV DC Ceramic Support Insulators

This thesis is founded on the investigation of the ion migration of 500kV DC ceramic support insulators for the production of the 500kV DC ceramic support insulators.In the test system, we added the grounding switch for each circuit and the mutual switch, prescribed the four status of the current measuring program, making the measurement system more stabile.on the base of the IEC standard of DC suspension insulators, we designed a new ion migration test for 500kV DC ceramic support insulators, including the regulation between the bulk resistance and the temperature, the test samples, the test voltage and the temperature for long-term ion migration test, and the amount of accumulative charges.Finally, after the long-term ion migration test, we analyzed the relation between the current and accumulative charge with the test time, computed the ion mobility and migration distance, and analyzed the distribution variety of Na+ and K+ in the test samples. The results indicate that, the effect on the electric and mechanical performances of 500kV DC ceramic support insulators could not be founded. But further research is needed.