The Reseach Of Electric Railway Power Conditioning Systems Based On Balance Traction Transformer

Electric railway with the advantage of high-speed,heavy-load,low-pollution,etc.,is the main artery of economic and social development.Modern electric locomotive gives priority to AC-DC and AC-DC type,while the old-fashioned freight trains are still as the mainline.Its operation of reactive power,negative sequence and harmonic is the bone of contention of electric power and railway departments.Facing the challenges brought by power system of electric railway,with the comprehensive comparison of traditional railway power conditioning system(RPC)and combined with a certain traction substation of measured data,a new type electric railway power conditioning system is proposed in this paper to give a comprehensive management for traction substation's power quality with balance transformer based on the National Natural Science Fund Project and the key Project Supported by Hunan Provincial Natural Science Foundation of China.The system is composed of passive components and active components together,it give a comprehensive management for power quality problems brought by traction power supply system.The following,a hybrid railway power quality management system(H-RPQMS)will be referred to as the new type of electric railway power conditioning syste m.The paper's main work and innovations are as follows:First of all,the topology of a hybrid railway power quality management system(H-RPQMS)is put forward.Inductance connecting reactances in RPC which are connected with traction network in this syst em will be replaced with LC connecting reactance of inductance and capacitance in series.The working principle of this compensation system are analyzed.The performance of inverter's output voltage was study in depth.The power capacity comparison between the proposed system and traditional railway static power conditioner(RPC)are analyzed in detail.The research indicates that H-RPQMS has a significant ability of power decreasing than RPC at the premise of compensation the same current.The overall cost is reduced and the device and its compensation effect are superior than RPC.On the basis of inverter's output voltage and capacity' analysis,the design method of optimal reactance of LC-connecting branches are given in this paper as well.Secondly,this negative sequence and harmonic compensation principle of power supply system for high-speed railway while use balance traction transformer are expound.The negative sequence compensation mechanism of the high speed railway power supply system is revealed.The high speed railway power supply system of negative sequence and harmonic detection method and control strategy are put forward.Finally,the statistics and probability analysis of measured data of a certain traction substation are given.It is modeled and simulated with the measured data of a certain traction substation.In view of the different operating conditions,each subsystem's compensation capacity of hybrid compensation system is put forward.Finally,the simulation based on a real traction sub station indicates H-RPQMS can get good negative sequence for locomotive operating conditions,and validates the effectiveness and power capacity analysis' s correct of H-RPQMS.