Energy Management And Capacity Configuration Of On-Board EDLC Energy Storage System Of Railway Vehicle

Compared with other transportation modes, urban rail transit has advantages of large carrying capacity, low energy consumption, high safety. With the popularization of regenerative braking in recent years, the problem of regenerative failure occurs frequently. How to secure a steady regenerative load using energy storage technology to prevent regenerative failure has been hotspot in the research in world’s urban rail transit. EDLC with low pollution, high efficiency, and long life cycle has own unique advantage and development prospect in preventing regeneration failure.Based on the background, this dissertation a deep research on control strategy and the capacity configuration of On-board EDLC energy storage system of railway vehicle.Frequency analysis method is used to study frequency characteristics of railway vehicle load and EDLC. In addition, this paper discusses the matching relationship. Through simulation and experiment, the first order model is sufficiently accurate for On-board EDLC energy storage system of railway vehicle controller’analysis and synthesis. To provide theoretical support for optimal design of energy storage device, the charging and discharging efficiency are studies in constant current and constant power mode.Considering the operating characteristics of railway vehicle and solving regenerative failure in DC traction power supply system, an indirect current control strategy is proposed. The control strategy contains line current loop, the DC line voltage loop, the EDLC current loop and the EDLC SOC (state of charge) loop. Not only realize the indirect control of the EDLC current but also make sure EDLC work in several operation depending on the operating condition of railway vehicle. Based on small-signal model of DC line voltage, the transfer function is obtained. To ensure good dynamic performance, the controllers of optimal damped ratio have to be designed for the minimum EDLC voltage. Based on small-signal model of EDLC current, the transfer function is obtained. To ensure the EDLC current smooth transition, a new approach for design the controller is proposed.The effectiveness of unified controller is verified through simulation and experiment.The constraint relationship between charge and discharge current of EDLC and SOC makes sure prevent EDLC overcharge or overdischarge.The experimental platform of EDLC energy storage system is developed. The dynamic simulation methods of single railway vehicle load and DC traction power supply system voltage fluctuation when multtiple railway vehicles running are realised. Adopting CAN bus, multiple devices can be simulataneously working and state variables can be observed. Based on experimental platform, verification of control strategy proposed is finished.In this paper, the research method of the capacity configuration from the global energy exchange between the railway vehicles and DC traction power supply system is proposed. The simulation platform for EDLC energy storage system is developed. To effectively solve the problem which the DC traction power flow calculation iteration did not converge under regenerative braking condition, the new DC traction power flow simulation algorithm-Equivalent method for component segmentation is proposed. The accuracy of method is verified by comparison of numerical calculation results and simulation results.Its relative errors are within0.5%.The capacity configuration method which aims to absorb surplus regenerative braking energy and considers the control strategy is proposed. Based on actual subway line parameters, an application example of the method in capacity configuration is discussed. The influence factors of capacity configuration are studied, particularly different control parameters. Based on multiple attribute decision making theory, optimal capacity configuration under the control parameters is obtained.