Passive Filter Design for Power Supply Systems with Traction Loads

The purpose of the investigation is to analyze resonant modes in electric power systems that feed the traction load, to study the mutual influence of the traction network and the external power supply system. Simulation model of the power supply system with traction load, implemented with the Matlab/Simulink software package, is considered. The proposed model is used to study the influence of various parameters of the power supply system on resonant modes, including the length of lines, the short-circuit power of the external power supply system, and the spectral composition of locomotive currents. It is shown that the study of resonant modes should consider the traction power supply system and the external network as a single system. Its frequency characteristics depend on both the parameters of the traction network and the parameters of the external power supply system. The ways to improve technical characteristics of passive filtering systems (PFS) for traction railway networks due to the sustainable choice of passive filter configurations have been investigated. Different PFS that provide compensation for voltage distortions in both the traction and external network have been proposed. They provide the suppression of powerful low-frequency harmonics and the resonant mode damping in the traction network – transformer – external network system. Broadband filters of the 3-5 orders have been proposed to control the characteristics of the traction power supply system