Power flow modelling and loss analysis of urban rail traction power supply system considering cross-bonding cables

The urban rail transit traction power supply system adopts DC power supply. The upstream and downstream rails are generally connected by cross -bonding cables at intervals, so as to decrease the rail equivalent resistance and reduce the rail potential and loss. The existing modelling methods for power flow calculation do not consider the influence of cross -bonding cables due to the complexity of modelling, which causes some deviations in the calculation results. Hence, a modelling method for power flow calculation of urban rail transit traction power supply system considering cross -bonding cables is proposed in this paper. Firstly, the influence of cross -bonding cables on power flow model is analyzed. Subsequently, a model simplification method based on multiport network hybrid parameters is designed. Finally, power flow calculations considering cross -bonding cables are carried out with a metro line. The calculation results show that the calculation difference of traction network loss before and after consideration is more than 10 %. Moreover, this paper analyzes the influence law of the setting of cross -bonding cables on the power flow state, and gives some suggestions on the setting in actual engineering application.