Research On The Reliability Of Novel D.C Traction Power Supply System For Urban Rail Transit

This paper researches the reliability technology of novel metro traction DC power supply system (NPS) contacted with the rectifier dirved by diodes, including the reliability of the ground system, switch equipment, the EMS of power transition system and the application of IGBT as follows:First, take a conclusion of the design principles in the diodes reflicter, and gets the ones fit for the NPS. Compare the similarities and differences of two systems and give a new principle for NPS.Second, the main equipments of the NPS are researched in the paper. The selected principles of the rectifier transform and the switch equipments are given. Also, the capability of the transform is calculated and the method calculating for switch equipments' parameters is designed.Third, researches the power module of the reflicter and analyse special demands for IGBTs in NPS. The reasons for the demands of a good thermal circulate ability and overload ability are given. The characteristics of IGBT working in common and under fault are also discussed in the paper; what's more, the method to improve the performance of IGBTs is given by analysing the stray parameters of IGBT, comparing the method between IGBT drivers, and analysing the advantages and disvantages of them. At last, an IGBT drive module with a short circuit protection for the NPS system is designed.In the end, this paper gives an EMC design for the reflicter system. Inductance calculation formulas for 4 typical connection loops of conductors are established and diferent inductance calculation methods are suggested for film-insulated laminated bus. And the EMI caused by the power circuit is analysed. By the calculation of the stray inductance in the power circuit, the paper also designs a snubber circuit of which result shows a good ability in over voltage control of it. At last, an EMC design of the control system is given.