Scheme design and configuration optimization of self-consistency energy systems for rail transit

To improve the rationality of the construction of self-consistency energy systems for rail transit, the EMU trains on the Beijing-Zhangjiakou Railway were taken as the research objects. According to operating scenarios and line conditions, the topology scheme of a wind-photovoltaic-storage microgrid self-consistency energy system based on the railway power conditioner was determined. Through traction calculation for the longitudinal operation of the EMU trains, the energy flow relationship during train operation was analyzed, and a real-time energy management strategy was designed. Under the premise of reasonable power distribution, with the economical and lightweight wind-photovoltaic-storage self-consistency energy system as optimization objectives, multi-objective optimization technology for the configuration scheme of the self-consistency energy system was studied. Under the conditions of the established line and power constraints, the particle swarm optimization algorithm was used to optimize and calculate control variables of the self-consistency energy system such as the number of photovoltaic cells in series and parallel, the number of storage batteries in series and parallel, and the scale of wind turbines, so as to achieve the optimal configuration scheme of the wind-photovoltaic-storage self-consistency energy system under the given line conditions and objectives. With the actual line conditions of 16 CR400BF trains on the downline of Beijing-Zhangjiakou Railway as an example, the proposed optimized configuration scheme of the wind-photovoltaic-storage self-consistency energy system was verified through MATLAB/Simulink software. Combining the two optimization objectives of the total lifecycle cost of the system (including initial purchasing cost, replacement cost, and electricity purchasing cost) and the total volume of the occupied area, the configurations were optimized by using three different sets of weight coefficients. Analysis results show that with the increase in the weight of the economic objective, the total lifecycle costs of the corresponding optimized configuration schemes reduce by 191.649 million yuan (about 49.1%), 188.258 million yuan (about 48.2%), and 179.911 million yuan (about 46.0%). As the weight of the lightweight objective increases, the total volumes of the optimized self-consistency energy system along the line reduce by 3 377.2 (about 50.4%), 3 393.7 (about 50.6%), and 3 446.9 m³ (about 51.4%). 6 tabs, 15 figs, 31 refs.