Research On Automatic Over-phase Technology Of Electric High-speed Railway

In the traction power supply system of high-speed railway in China,there is an electric phase separation area for every 20-30krm Not only in China,but also in other countries where electric locomotives are highly developed,safety and reliability through the electric phase sqparation area has always been a subject of continuous progress and continuous improvement.At present,the switch action has been transferred to the pillar in the column vacuum isolating switch technology,but it has caused great damage to the traction power sipply system and the electric locomotive itself in such problems as overvoltage and overcurrent.The performance of vacuum switch itself is also difficult to maintain high frequency operation for a long time,which leads to the increase of maintenance and maintenance costs.There are three kinds of automatic over-phase schemes in the world:the on-colxumn switch automatic power-off over · phase scheme,the vehicle_mounted automatic control over-phase scheme,the ground switch auto-over-phase scheme.The present invention uses vehicle-mounted automatic control automatic over_phase scheme,the action of the vehicle-mounted device increases the frequency of the vehicle-mounted equipment,the over-voltage phenomenon is obvious?the service life of the vacuum switch is low,the switching action cannot control the conduction voltage phase angle,etc.The invention can solve the problems that the,vacuum isolating switch can not control the conduction triggering phase angle,reduce the transient phenomenon,use short service life,and the high-speed locomotive is too large throug^h speed toss.In this paper,the present technology of magnetosteel and vacuum isolator is analyzed and calculated,and the expression of voltage and current in neutral section is deduced.The key factors affecting neutral voltage and current and the existing problems are also given.Then,a new scheme based on post type power electronic switch is presented,and the structure of power electronic switch system and the.type selection of power electronic device are designed.The internal circuit construction of power electronic switch,the equalizing circuit of power electronic device,the impedance selection of buffer circuit,etc.Finally,the excessive phase process of power electronic switch system is simulated by matlab/simulink module.The simulation results show that the power electronic switch system can reliably realize the automatic over-phase of the locomotive,effectively solve the existing high voltage circuit breaker frequent operation,short repair period is easy to damage,the tocomotive overphase operation overvoltage is too high.The problems such as the power quality decline,the excessive speed loss of the excessive phase loss time of locomotive and the insufficient service life of the cylinder vacuum switch are easy to affect the fatal weakness that the operation has not been popularized and so on.