Power Sharing Control of High Speed Railway Traction Networks Supplied by Dual End Substations

This paper presents a novel power sharing control for high speed railway traction networks which are supplied continuously by dual end substations without the neutral section. The power sharing between two substations is realised by droop control where the droop coefficients are updated based on the actual traction load distribution for a given specific active power sharing ratio, while the power sharing ratio is optimised for the least conductor line losses under the light-medium load condition. For the heavy load condition, power at both substations are more balanced so that the substation capacity can be set at a lower rating. The proposed approach is tested on a simplified single-track network model which supports continuous traction dynamics and auto-transformer connection, and simulation results confirm that the proposed method has advantages of increasing the supply distance compared with the conventional transformer substation scheme. It offers greater power supply capacity than the fixed frequency substation control scheme, and it also achieves less power losses than the equal power sharing strategy proposed in the existing studies.