The EMC Analysis And Design About Supervisory System Of Catenary Switches

With the large-scale building of high-speed electrified railway in our state, the reliability of its power supply has been paid more attention. Using supervisory system for catenary switches is an important approach to isolate faults in traction power systems (TPS). Its effectiveness and reliability directly influences the operation of electrified railways. Electromagnetic interference (EMI) from its environment can make it invalid. So, research on electromagnetic compatibility (EMC) of supervisory system of catenary switches has practical meaning.First, this thesis has thoroughly reviewed current applications and progress of supervisory system of catenary switches both in China and abroad. Based on that, a contrast of centralized and distributed supervisory system of catenary switches has been given. The source and danger of EMI of supervisory system of catenary switch has been discussed. This work laid a foundation for subsequent analysis.Secondly, the thesis puts emphasis on the EMC research on centralized supervisory system of catenary switches. Equivalent circuit supervisory control system of AT power supply mode has been given. Simulation models of control cables about AT power supply mode have been established. Based on this, a series of simulation analysis has been done. The EMI of traction power supply system's primary system to cable signal has been verified. It can cause maloperation of catenary switch and false alarm of remote signals. By simulation analysis of effect on the cable signals between cables that cable length, harmonic and voltage fluctuation has, cable length, and harmonic and voltage fluctuation can cause crosstalk of signals between cables, which can lead to distortion of current signals transmitting through control cables.Lastly, the thesis has mainly designed distributed supervisory system of catenary switches transmitting information through optical fiber. Its detailed structure has been discussed. Because of potential hazards of EMI, the thesis has made overall EMC design for distributed supervisory system of catenary switches. At the view of EMC, circuit components have been chosen. The thesis has made EMC design for Remote I/O unit including circuit, PCB and enclosure design.Some tests indicate that, the EMC design of distributed supervisory system of catenary switch transmitting information through optical fiber is successful. Its steady and reliable fieldwork has proved validity of EMC design.