An improved forbidden-region-based criterion of vehicle-grid system

In this paper, an improved stability criterion based on the forbidden region is proposed for analysis of the low-frequency oscillation (LFO) arising in the electric railway system when multiple AC-DC-AC drive locomotives get charged at the same power supply section simultaneously. This criterion is simple to calculate and has low conservation. The LFO was successfully reproduced by establishing the time-domain simulation model in MATLAB/Simulink. Then the influence of gird-side parameters, traction-side parameters and converter control parameters in CRH5 on the LFO of vehicle-grid (V2G) system is discussed through simulation. Finally, the validity of the proposed criterion was verified by simulation.