Energy loss minimisation by optimal design of stationary supercapacitors for light railways

This paper presents a methodology to design the optimal capacitances and locations of stationary supercapacitors for light DC railways based on a single train simulator. The objective function of the optimisation problem takes into account the energy consumption of the substations and the total line energy loss. The problem includes an isoperimetric constraint to maintain to zero the net energy supplied by supercapacitors at the end of each cycle. The suitable fitting weight coefficients employed in the objective functions can be obtained by the Genetic Algorithm and Particle Swam Optimisation. The learning process of the optimisation procedure studies the effect of the energy storage capacity for different positions of supercapacitors along the track. From the optimisation algorithm it has been found that the minimal capacitance for each section is obtained when supercapacitors are located around the middle between two adjacent substations. Finally, the examples of the practical design of the supercapacitors modules have been presented by using commercially available modules.