Energy consumption evaluation of urban rail transit system by improved simulation models and actual measurement verification

Simulation models of DC (direct current) traction power system have great relationship with the accuracy and efficiency of the load flow calculation which has significances to the assessment of electric energy consumption of the urban rail transit system. The external characteristic of rectifier units and braking resistance, current limited control of trains are important factors which are closely associated with the calculation accuracy and efficiency but were usually simplified in previous studies. In this paper, the models of rectifier units, braking resistance and the current-limiting curve of trains are discussed in detail and the improved models are put forward, the mathematical model of whole traction network is established according to the three layers model. The load flow algorithm applied to the improved models is also studied. Energy consumption calculation formulas of each part are provided, including SIV energy. A dynamic simulation system is finished based on the power flow algorithm of DC network. By comparing with actual data and comparing with each other, the accuracy and relative efficiency of each model is obtained. And the suitable conditions of each model are analyzed respectively. The comparison results also verify the high calculation accuracy and strong practical feasibility of the simulation system consist of improved models.