Modeling And Simulation Of DC Traction Power Supply System With Regenerative Braking Energy Recovery And Utilization Device

At present,the most metro vehicles in China are equipped with braking resistor,which consume extra regenerative braking energy in form of heat.With the development of power electronics,a lot of non energy dissipation schemes have been developed,including four-quadrant inverter and energy storage equipment.The current development trend in the urban rail transit field has led to an ever increasing interest for the energetic optimization,especially considering the braking phases.However,the existing software can not meet the requirements for the design of regenerative braking energy utilization scheme.Through the analysis of the structure of actual power supply system,this thesis designed and realized a full graphics metro power supply simulation software considering the regenerative braking energy recovery and utilization device.Firstly,through the investigation and analysis of the composition and operation mode of the DC traction power supply system,a three-layer mathematical model which consists of traction network,rail,and earth is established,and a four-layer mathematical model considering the stray current collection network is also established.Secondly,based on the working principle and control strategy of regenerative braking energy utilization devices,appropriate mathematical models which are suitable for traction power supply calculation of engineering are established,including vehicle braking resistor,super capacitor energy storage device,battery energy storage device and medium voltage energy feedback device.The static and dynamic power flow algorithms are compiled to meet the design requirements combining the characteristics of rail transit.Through the discussion about the simulation software implementation scheme with engineers,the need for good visualization and interaction of the software is clearly defined.A graphical modeling method is designed,and data interaction between each module is realized through interface design.The component parameters of the DC power supply system are analyzed in detail through the investigation of Shenzhen metro power supply system,which lays a foundation for the simulation analysis,comparison and verification.A capacity configuration methord for regenerative braking energy recovery and utilization device is proposed.The capacity configuration of energy storage devices under different plans is studied through simulation.The effect of charge and discharge voltage threshold on the energy saving of the system uder different departure intervals is also discussed.Finally,the design of simulation platform of DC traction power supply system is completed.The application value of software in engineering is illustrated by simulation examples,which provides a reference to the users for the optimization of the system design,the selection of equipments,the optimization scheme of regenerative braking energy and the analysis of economic effect.The recovery years of DC traction power supply system equipped with the energy feedback device are analyzed.The software has Windows style,and can be installed and run independently,it's easy to learn to operate.The software has been preliminarily applied in engineering at present.