Research On Optimal Capacity Configuration Of Railway Power Conditioner

For the electrified railway power system,the capacity configuration of the compensation device of the high-power converter is of great significance for its wide application.The railway power supply under V/v transformer is considered as research background in this paper,in view of the conventional railway power conditioner(RPC),the operating speed of RPC can be made faster by changing the control strategy,while the operating loss of the RPC is reduced.Otherwise,the one-time investment cost of the novel railway power conditioner with super capacitor(SC-RPC)system can be reduced in this paper.The main research chapters of this paper are as follows:First of all,the research background and significance of the subject are introduced in this paper,and the characteristics of the Scott transformer and V/v transformer in the traction transformer are analyzed.The related power quality control methods of electrified railways at home and abroad are expounded.The basic principle and current research of RPC are analyzed emphatically,which shows that it is of great significance to reduce the compensation capacity of RPC.Secondly,a satisfied compensation method based on sensitivity decoupling is proposed.The relationships between power quality index and compensation capacity and its compensation parameters in RPC optimization compensation are studied.The proposed method reveals the influence degree of the compensation parameter on the voltage unbalance degree,power factor and compensation capacity.Based on the given compensation scheme,the numeral cases are carried out according to different working conditions.The results of the example show that the proposed compensation strategy can reduce the RPC operating capacity under the premise of meeting the power quality indicators,and the fastness and reliability of high-power converter operation are guaranteed.Finally,based on the regenerative braking problem of high-speed railway,the basic working principle of SC-RPC is described,and the regenerative braking energy of high-speed railway is analyzed.The energy utilization rate of regenerative braking is derived under various working conditions.Under the condition of satisfying certain energy utilization rate,the opportunity constrained programming model with the one-time investment cost of the energy storage system is established,and the genetic algorithm based on stochastic simulation is used to solve it.The numeral case shows the capacity allocation results under different confidence levels and different energy saving rates,which provides a new method for the capacity allocation of the energy storage system in SC-RPC.