Power Flow Calculation Method Research On Metro Traction Supply System By Consider The AC/DC Coupling

Today's China,the urban rail transit construction,especially in the subway construction have to carry out in full swing.With the rapid growth of construction and operational in subway lines,how to reduce engineering investment and to operation cost,how to optimize the overall design and to run the program,how to guarantee safty operation of metro lines has been related to the real challenges to the practitioners and researchers,and related research of metro traction power supply system power flow calculation will provide the basis for the above problems.But most of the existing metro traction power supply system power flow calculation method without considering the mutual coupling between communication trend and DC current,lead to flow calculation accuracy is not high.To solve the above problems,this paper using a thinking of AC/DC current mutual coupling hybrid iteration of metro traction power supply system power flow calculation method and its application to practical engineering projects.The subway traction power supply system of the AC/DC power flow calculation research focus mainly on two aspects: on the one hand,AC/DC power distribution network tide calculation;In AC/DC power distribution network tide,on the other hand,the iterative algorithms in the process of calculation.AC/DC power distribution network tide calculation will be done separately and AC side and DC side of the power flow calculation of metro traction power supply system by computing to available of all nodes size of the voltage and current of AC side and DC side.Moreover AC/DC power distribution network tide calculation iteration algorithm in the process of study which through the adjusted results of interaction on both sides of the power flow calculation,will realize between AC side and DC side current of decoupling.For AC/DC power distribution network tide calculation,in this paper,the subway traction power supply system is divided into three subsystems,and the part of AC system and DC system containing circuit element mathematical model is established,respectively,are derived for metro traction power supply system,the mathematical model of traction substation module,on this basis,the theoretical derivation of the traction power supply system of metro AC side current and DC side of the power flow calculation method.In the process of AC/DC power distribution network tide calculation,taking into account the subway traction power supply system of AC/DC current coupling problem,this paper using a subway traction power supply system based on interface parameter correction equation mixed current iteration method.Through a separate design trend of the rectifier unit model of traction power supply system will communication system with the rectifier unit interface parameter modification,rectifier unit and the interface parameters of DC system,and the results of the DC power flow calculation and modified AC flow tide calculation result to each iteration,realize the decoupling of AC/DC current iteration.Verified by the example analysis in this paper which based on the interface parameter correction equation of metro traction power supply system model and its feasibility of the algorithm.The experimental results show that the proposed considering AC/DC coupling of metro traction power supply system power flow calculation method on the precision and convergence is optimal and conforms to the actual effect than that is not considering the trend of coupling calculation method.