Survey of loss minimization methods in tram systems (original) (raw)
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Tram simulation model for energy balance analyses
2017 21st International Conference on Process Control (PC), 2017
This paper describes a mathematical model of a tramcar which allows to simulate traffic on any tram track and allows to analyze energetic balance on the electrical power link without real energetic data measurement. The described mathematical model could be a useful tool for the design of an energy recovery system for a real tram track. A short description of the tram track model in the city of Liberec is presented together with the mathematical model of the tramcar type T3.PLF that operates on mentioned track. The model simulation results are confronted with data measured during the real tram operation.
2021
Electric trams are one of the standard forms of public transport. They are characterized by large amounts of electric current and electric current gradient from the power grid, especially during acceleration. For this reason, a regenerative braking system is considered with the aim of reducing electric current peaks and increasing energy efficiency by reducing the total energy consumption of the power grid. A supercapacitor module is used as a storage device for storing and utilizing the braking energy. The supercapacitor module and the power grid constitute a hybrid energy system, for which a control algorithm has been developed. The control algorithm takes into account the influence of the elevation profile and the slope of the vehicle route in storing and using the braking energy. The operation of the algorithm was simulated and analyzed using the MATLAB/Simulink software package for tram lines with different elevation profiles.
Energies
Energy savings in electric rail transport are important in order to increase energy efficiency and reduce its carbon footprint. This can be achieved by storing and using the energy generated during regenerative braking. The system described in this paper consists of a supercapacitor energy storage system (SC ESS), a bidirectional DC/DC converter, and an algorithm to control the energy flow. The proper design of the algorithm is critical for maximizing energy savings and stabilizing the power grid, and it affects the lifetime of the SC ESS. This paper presents an energy flow control algorithm based on Pontryagin’s minimum principle that balances maximum energy savings with maximum SC ESS lifetime. The algorithm also performs SC ESS recharging while the rail vehicle stops on inclines to reduce the impact of its next acceleration on the power grid. To validate the algorithm, offline simulations are performed using real tram speed measurements. The results are then verified with a real-...
Energy and exergy efficiencies in urban electric transportation systems
This paper aimed at examining an underground railway train as a system where different energy forms occur, so that the successive energy conversion chain is emphasized and the energy and exergy efficiencies, respectively, are compared. The study case presented in the paper emphasized the operation of the static converters and the traction induction motors as an assembly, both in the traction regime and in the electric brake regime, for different urban underground metro trains produced by Craiova Electroputere Factory for Bucharest Underground Trasportation System. In this application, the exergy analysis can help improve and optimize the underground transportation system design and operation.