Energy Storage Systems Simulation For Metro Network

With the development of urban rail transit, the recoverable energy absorption device have an important implications in urban rail systems and energy saving. This paper will focus on the supercapacitor energy storage system, later on traction power station with the recoverable energy absorbing device will be analyzed and researched.Firstly, this paper gives a brief introduction to the regeneration braking power storage system in urban rail transit system.The regeneration braking power model especially focus on the equivalent24pulse rectifier unit model and its external characteristic, as well as rail equivalent circuit.Then the regeneration braking power model is established, and author points out a dynamic network model with a fixed topology and triangle decomposition method based on Gaussian main element method to calculate the model.At last the regeneration braking power model is iteratived based on the rail over-voltage protection device and the rectifier unit.Secondly,author analyzes and determines the stationary supercapacitor energy storage system as this papers’subject.Later on author gives an introduction in detail to the supercapacitor, and establishes a unified control strategy for Bi-directional DC-DC Converter (BDC).After that, an effective compernsation for the dual-loop control mode of the inner current loop and outer voltage loop with PI is estabilished to achieve the positive and negative bidirectional operation stablely.According to the actual situation of rail transit system,author points out an effective control strategy based on the network voltage and the supercacitor energy state to transform smoothly in the charging state、neutral state and discharging state,so as to achieve the purpose of saving energy and stabilizing voltage.Finally, according to the Chengdu Metro Line2information and the regeneration braking power model, calculate the traction calculation and the regeneration braking power calculation. Carried out a detailed design for supercapacitor energy storage system, then designed and verified the state control strategy.At last,there is a unified simulation for the regeneration braking power storage system, after numbers of simulations the size of supercapacitor each traction station required is determined.