Rail transit power supply system and centralized reactive power compensation method and device thereof

The application provides a rail transit power supply system and a centralized reactive power compensation method and device thereof. The centralized reactive power compensation method of the rail transit power supply system comprises the steps that the concentrated reactive power compensation device receives, from each energy feed device, the allowable to-be-emitted reactive power of each energy feed device and the real-time reactive power should be compensated for a medium-voltage power supply network by each energy feed device; determining the reactive power to be compensated by a main substation; based on the reactive power to be compensated by the main substation, the allowable to-be-emitted reactive power of each energy feed device, and the real-time reactive power should be compensated for a medium-voltage power supply network by each energy feed device, determining the reactive power compensation power and the concentrated reactive power compensation power of each energy feed device; and transmitting t