Study On Static Power Conditioner Of Electrified Railway With Energy Storage Device

Due to the reasons including the heavy load of railway,the non-li.nearit.y of po.wer electronic equipment and the po.wer sup.ply mo.de of elec.tric locom.otive,the prob.lems of neg.ative sequ.ence cu.rrent,harmonic current and regenerative braking energy’s impact are increasingly brought to the grid and trac.tion po.wer sup.ply system.The railway static power conditioner achieves grid voltage balance by dynamically adjusting the active power balance and reactive power compensation from the two power supply arms.Based on this technology,to solve the problem that a large amount of regenerative braking energy cannot be effectively utilized in the trac.tion pow.er sup.ply sys.tem,a new type of railway static power conditioner with energy storage device is proposed in this thesis.The system can not only achieve the bidirectional energy flow between two power supply arms,but also effectively recycle regenerative braking energy.At the same time,the proposed con trol strategy can better solve the problem of negative sequence and harmonic current compensation after the energy storage device is connected to the trac.tion pow.er sup.ply sys.tem.The main research contents of this thesis include:Firstly,the power quality management technology and regenerative braking energy recovery technology of trac.tion pow.er sup.ply sys.tem and their applications are discussed in this paper.The power quality characteristics of various traction power supply systems are analyzed and compared next.And the status quo of RPC technology is summarized,so as the signi.fican.ce of t.he sub.ject.Secondly,to solve the problem that regenerative braking energy cannot be effectively utilized in traction pow.er sup.ply sys.tem,a new type of railway static power conditioner with energy storage device is proposed.Its topology,also the bidirectional DC-DC converter and energy storage device in the energy storage system are analyzed,so the main design of the system is completed.In t.his pap.er,four typical working conditions are analyzed,the equivalent circuit is constructed,and the utilization rate of regenerative braking energy under various working conditions is compared and analyzed.Based on the traditional negative sequence and ha rmonic current detection method and RPC control strategy,the improved detection method,control strategy and energy storage device’s control strategy are studied to ensure good comprehensive management effect.Finally,the simulation model of the system based on Matlab/Simulink platform is built,and the simulation experiments are carried out for various working conditions.The results of the simulation show that the system has better comprehensive control of the electric power quality of the electrified railway under various working conditions,it also solves the problem that the regenerative braking energy cannot be effectively utilized.The results confirm the correctness and feasibility of the system’s theory.