Catenary DC Ice-Melting Technology and Device Development of Electrified Railway

The icing of traction network seriously affects the normal operation of trunk railway.The characteristics of catenary ice-melting are described.The regulated method of ice-melting current and voltage be changed with the thickness of ice and the distance of the ice-melting line is discussed.A new ice-melting circuit topology witch based on power unit chopper cascaded is proposed.Equivalent circuit of this device with parallel input and output series is promoted,and the control methods of multiple rectifier is analysised.The input harmonic and power factor of phase dislocation four-quadrant rectifier is studied.The control method of chopper tolerant-phase output of cascaded power units is put forword.The working state of the circuit is analysised.The relationship of cascaded power unit voltage balance control principle,chopper output duty cycle,and capacitor voltage are studied and simulated.The high power experimental prototype is designed and full power experimental is completed with short of voltage feedback method.The results show that this ice-melting circuit has steady output voltage with low input harmonic content.It will do little influence on electric network,and can be applied to engineering practice effectively.