A Study On Power Flow Control Strategy Of Co-Phase Connected Power Supply System

Negative sequence, harmonics and reactive power are problems exist in railway Power supply, seriously affecting the development of high-speed and high-load railway., a variety of improvements and solutions have been proposed to solve these problems. Such as the pre-passive symmetrical compensation technology, it was able to improve the above-mentioned power quality problems, but it is difficult to fundamentally solve. The problem is the electric phase separation still exists. The co-phase traction power supply system based on the SVG can solve the above problems, it has been put into trial operation and proven to minimize those problems, and it has electric phase break.Reference to the results of previous studies, this paper focuses on doing a further study of the co-phase connected power supply system, and proposed a suitable flow control strategy. Currently the study of the co-phase connected power supply system is to model and simulate the integrated power flow controller. On this basis, this paper made a research and analysis on the AC-DC-AC converter’s operating in parallel and used two control strategies to model and simulate it. In addition, this paper made a research and analysis on the substation’s operating in parallel. The integrated method of controlling adopt the combination of droop control and inverse droop control, the substation used droop control to keep the system voltage,which used inverse droop control to support the system voltage and is able to control its output power, the substation’s capacity can be limited. Using two different control strategies improved the stability of the system, and ensure the stability of the system can be better when the system failure or shock. With establishing and analyzing the simulation model of co-phase connected power supply system by MATLAB, both dynamic and steady performances of the system, which controlled by the synthetic control strategy, have been proved well.