A Novel Traction Supply System Based On AC-DC-AC Inverter

The current traction power supply system has adopted different phase power supply technology. Traction power supply system for electrified railways have seriously unbalanced three phases and large amount of harmonics and reactive power and such systems need neutral section insulators to be installed in all power districts. This lays restraints on development of high-speed heavy-load railways. Now, a new cophase traction power supply system based on the extensively development of power electronics technology is proposed. We hope the cophase traction power supply system could solve the existing problems, at the same time could minimize the electricity on the power system for pollution. New type of traction power supply system mainly include PWM voltage source rectifier, rectifier part of the DC energy storage, SPWM inverter.Three-phase voltage source PWM rectifier is elabrated and analyzed the working principle, mathematical model, control strategy and regulator parameter design for the VSR. The system voltage is from 66 kV into 96 kV. The main circuit, the driving circuit, the control circuit and the protection circuit are designed; PWM technology applications can greatly reduce the power system pollution.DC energy storage part is stored electrical energy, including the release of this part to the system of power, but also to this part of the release-load power, while multiple harmonics can be played wipe out the role, using ordinary electricity capacitors and high-capacity power to achieve DC link capacitors the energy storage and transmission functions.The single-phase voltage PWM inverter will change the system from DC 96kV into AC 25kV.One SPWM inverter is designed in my subject, including the reasonable switching device parameters, with the realization of two parallel models of inverter operation and control strategies.In the last, the results of the simulation are verified the correctness of the design system.The subject will not only solve the problem of phase separation, the realization of the full link up with the supply, implementation of high-speed, heavy-load electric traction line; but also minimize seriously-unbalanced three phases and a large amount of harmonics and reactive power of traction power supply system.