Voltage Distribution and Regulation of Multi-interrupter SF6 Circuit Breakers for HVDC Grid

Abstract

The multi-interrupter SF6 circuit breakers are widely used in High Voltage Direct Current (HVDC) station. The AC filter circuit breakers play an important role on the reliability of the grid. In this paper, the voltage distribution of the multi-interrupter circuit breaker is researched and the regulation method is obtained. First, the equivalent model of four-interrupter SF6 circuit breaker is established. The equivalent circuit is composed of controlled post-arc sources, post arc resistors and equivalent capacitors. The equivalent capacitance and stray capacitance across each interrupter were calculated by using finite element analysis software (ANSYS). Then voltage distribution was simulated under the condition that different measures were adopted. The measures include paralleling resistance, capacitance and resistance-capacitance. Comprehensive comparison of various voltage-sharing measures, paralleling capacitance and resistance is suitable for multi-break SF6 circuit breaker at the present condition. At last, experimental system was built based on Weil synthesis circuit to seek suitable scheme. The test results verify the simulation analysis, which indicates that the grading resistance-capacitance is suitable voltage regulation method.