Multifunctional control strategy of Half-Bridge based Railway Power Quality Conditioner for Traction System

The extension of electrical railway systems causes critical power quality problems in the power grid. This paper presents a kind of Half-Bridge Railway static Power Quality Conditioner (HBRPQC) based on a half-bridge converter which can compensate Negative Sequence Currents (NSC), harmonics and reactive power simultaneously. In this paper, a new multifunctional control strategy based on modified instantaneous reactive power (p-q) theory is proposed to keep the HBRPQC performance efficient and suitable for different kinds of transformers used in Traction Power supply Substation (TPS). Due to the fast dynamic of traction loads, a hysteresis current controller is used to generate pulse signals of HBRPQC switches. Finally, the presented control method is simulated for V/V and Y/Δ11 transformers by Matlab/Simulink software. The simulation results validate the correctness of proposed control method.