Reseach On Dynamic Model Of Full Parallel AT Traction Electric Network Based On Hardware-in-loop Platform

The construction of high-speed or heavy-load electrified railways is regarded as an important engine to promote the development of the national economy in the new era.The fully parallel AT traction power supply system(TPSS)with strong power supply capability is very suitable for high-speed or heavy-duty railways,but the traction network is prone to threatening short-circuit faults during operation.China has neither fully grasped the electrical characteristics of AT traction network,nor has a suitable real-time simulation model,which makes it difficult to set the feeder protection.Taking into account the difficulty and risk of actual short-circuit tests,it is necessary to build a real-time simulation system of full-parallel AT TPSS and feeder protection by hardware-in-loop-based,and comprehensively analyze the short-circuit characteristics of the traction network by the real-time dynamic simulation.Firstly,the paper briefly describes the structure and working principle of the fully parallel AT TPSS and determines the specific power components of the system modeling.The six-conductor physical model of the AT traction network is established by the space topology and current flow of the power line,and the unit impedance calculation model between wires are established based on the Carson theory and power supply loop.According to the description of protection configuration for the AT traction network,the working principle and the setting rules of distance protection I section,current quick-break protection and current incremental protection are qualitatively analyzed.Secondly,according to the equivalent circuit and the electrical parameters of power components and lines,the simulation parameters of each power component are calculated and configured in the simulation model of each functional module;the simulation model of the fully parallel AT TPSS is built and uploaded to the power system real-time simulation platform.After that,RT-plus compiles the system model.The short-circuit simulation experiment at the specified location is carried out,and the simulation accuracy of the system model is verified by comparing the measured data.Finally,the real-time simulation results of RT-plus are used as the input signal of the power amplifier through the CAN bus,and the amplified signal is directly delivered to the feeder protection device to form the dynamic simulation experiment system of the full parallel AT traction network based on the hardware in the loop.By setting different short-circuit types and short-circuit position points,the short-circuit features between different conductors of traction network and the correctness of feeder protection action are quantitatively analyzed.It is proved by lots of real-time simulation cases that the dynamic simulation experiment system can not only develop a high-fidelity dynamic simulation experiment system for full-parallel AT traction network based on hardware-in-loop,but also can analyze the rationality of the new feeder protection principle through short-circuit simulation.