Research on motion characteristics and stability of 500kV fast mechanical switch

Abstract

The key component of fast mechanical switch (FMS) is electromagnetic repulsion mechanism (ERM), and the stability of ERM has an important influence on fault breaking time and breaking performance of hybrid DC circuit breaker (DCCB). In this paper, a FMS based on ERM is designed. In order to improve the stability of the FMS, the key factors affecting the stability of the excitation coil resistance, the inductance of the excitation coil, the capacitance of the energy storage capacitor, the charging voltage and the ambient temperature are analyzed. Then, 2D ERM simulation model is set up and study the above parameters deviation and the change of environmental temperature on the repulsive force driving characteristics. In order to ensure that the ERM moves to 10mm in 2ms, and the time dispersion is less than ±0.2ms. The reasonable variation ranges of each parameter required for the stable action of the ERM and the appropriate working environment temperature are determined. Finally, the developed FMS prototype was tested for opening, temperature rise and consistency, and the test results were consistent with the simulation results.