Iterative techniques for the solution of complex DC-rail-traction systems including regenerative braking

Electric railway traction power systems are usually modelled as branched ladder electrical circuits with many variable power loads changing in time and moving in space. Effective simulation of these traction power networks depends both on understanding the nature of the system and hence accurate modelling, and on selecting efficient algorithms for the iterative part of the solution. Simulation models are normally required to include the effect of regenerative braking and make provision for the calculation of other variables such as rail potential. In this respect, the paper by Cai et al. (1995) considers the performance of various traction network iterative solution algorithms for networks with regenerative loading giving train and rail voltages. However, the paper leaves several important points unaddressed. The purpose of this correspondence contribution is to provide more information on the background to the work including difficulties in verification, and on the provision of realistic models for the rail-to-remote-ground and substation ground conductances