Novel Application of PWM Switching for DC Traction Circuit Breakers

摘要

Problems experienced with the use of conventional high speed circuit breakers (HSCB) in rail traction systems is highlighted. The design of a solid state breaker is investigated and after reviewing specifications of various power devices and reports it was decided that the integrated gate controlled thyristor (IGCT) would be the most suitable device for use in a DC circuit breaker as recommended. A novel design employing PWM switching, for shaping the trip curve, has been simulated and a prototype suggested. Matlab/Simulink simulations based on practical traction substation parameters show expected voltages and currents at various points in the circuit A simplified traction schematic diagram shows the basis of the simulations and an area of typical application. A block schematic diagram highlights the basic electrical design. In conclusion an air-cooled mechanical design of the suggested 4kV 4kA power module is discussed.