Traction Power Supply Network Research Articles

Traction Power Substation Load Analysis with Various Train Operating Styles and Substation Fault Modes

The simulation of railway systems plays a key role in designing the traction power supply network, managing the train operation, and making changes to timetables. Various simulation technologies have been developed to study the railway traction power network and train operation independently. However, the interactions between the load performance, train operation, and fault conditions are not fully understood. This paper proposes a mathematical modeling method to simulate the railway traction power network with a consideration of a multi-train operation, driving controls, under-voltage traction, and substation fault modes. The network voltage, power load demands, and energy consumption according to the existing operation are studied. The hotspots of the power supply network are identified based on an evaluation of the train operation and power demand. The impact of traction power substation (TPSS) outage and a short circuit on the power supply network have been simulated and analyzed. The simulation results have been analyzed and compared with those of a normal operation. A case study based on a practical metro line in Singapore is developed to illustrate the power network evaluation performance.

Study on multi-function uninterrupted phase-separation passing system and its control method

At present, the sudden load change and the terminal voltage fluctuation are two mainly problems in the uninterrupted phase-separation passing (UPP) system. For further enhancing the reliability of the UPP system and compensate the voltage sag at the end of the traction power supply network caused by the suddenly connection of locomotive to the power grid, a multi-function uninterrupted phase-separation passing system (MUPPS) and its control strategy are proposed. It has the advantages of the linear load change and improving power supply reliability. Firstly, the topology and working principle of MUPPS are studied; secondly, the current variation characteristics of the bridge arm when the power is continuously supplied by MUPPS during the phaseseparation passing are analyzed. Then, the characteristics of MUPPS to provide reactive power and stabilize the terminal voltage of traction arm are analyzed. Then, the power transmission characteristics of MUPPS under emergency working condition are analyzed. Then, the control strategy in two conditions are proposed. Finally, simulation analysis and small capacity experiment are conducted. The theoretical analysis and test confirm the correctness and effectiveness of MUPPS.

System-Level Dynamic Energy Consumption Evaluation for High-Speed Railway

This article studied a system-level energy consumption evaluation method for high-speed railway. Three coupled subsystems, namely, the traction power supply network (TPSN), the traction drive system (TDS), and the wheel-track motion system (WTMS), were identified, and corresponding energy dissipation behaviors of subsystems were analyzed in typical scenarios. Then, the traction calculation technologies were applied to calculate the dynamic power and energy consumption in the WTMS for one train as well as for multiple trains scheduled by the train timetable in 24-h. On this basis, rated efficiency of the devices in the TDS was applied to calculate the corresponding dynamic power and energy consumption. Furthermore, dynamic modeling and power flow solution technologies were conducted to calculate the dynamic power and energy consumption of the devices in the TPSN according to the dynamic power of the TDS and the running parameters of the WTMS. Based on the dynamic power and energy consumption results in the subsystems, an energy source identification algorithm was proposed to realize the refined energy management, and a set of energy metrics was presented to evaluate the energy consumption performances. Case studies were carried out to verify the effectiveness and potential applications of the proposed method.

The Modeling and Simulation of DC Traction Power Supply Network for Urban Rail Transit Based on Simulink

In order to study the influence of the state of train on the power supply network of urban rail transit, it is necessary to model and analyse the DC traction power supply system and vehicles. Based on the analysis of the structure of power supply system for urban rail transit and according to the operating principle of train, the modeling method of traction power supply system is proposed. The model of DC traction power supply system and train are established in the Simulink environment. The speed, position and power of the train vary with time through simulation, so the electrical value of train operation such as voltage that changes over time can be obtained under the model. The simulation results and the measured data are consistent in the trend of change, but there is a certain difference in corresponding values (fluctuated in an acceptable range), which verifies the validity of the model. In addition, it compares the energy consumption of substations at different departure intervals.

Industrial frequency single-phase AC traction power supply system for urban rail transit and its key technologies

To avoid stray current and maintain the benefit of no phase-split in the DC traction power supply system, an AC traction power supply system was proposed for the urban public transport such as metro and light rail transit. The proposed system consists of a main substation (MSS) and cable traction network (CTN). The MSS includes a single-phase main traction transformer and a negative-sequence compensation device, while the CTN includes double-core cables, traction transformers, overhead catenary system, rails, etc. Several key techniques for the proposed system were put forward and discussed, which can be summarized as (1) the power supply principle, equivalent circuit and transmission ability of the CTN, the cable-catenary matching technique, and the selection of catenary voltage level; (2) the segmentation technology and status identification method for traction power supply network, distributed and centralized protection schemes, etc.; (3) a power supply scheme for single-line MSS and a power supply scheme of MSS shared by two or more lines. The proposed industrial frequency single-phase AC traction power supply system shows an excellent technical performance, good economy, and high reliability, hence provides a new alternative for metro and urban rail transit power supply systems.