The monograph is devoted to the use of distributed generation plants and power routers in AC power supply systems of railways. Indicators characterizing the quality of electric power in electric networks adjacent to traction substations are analyzed, issues of the influence of asymmetry and harmonic distortions on the operation of low-power generators are considered. The results of modeling the modes of power supply systems equipped with distributed generation units implemented on the basis of synchronous and asynchronous machines are also presented, the issue of eliminating flicker in networks with low-power generators is considered. The results of modeling power supply systems built using power routers are presented.