Research on a novel power quality conditioner with PV for electrified railway

摘要： With the fast development of electric railway, harmonics and reactive power problems caused by electric locomotive load remains to be further improved. This paper presents a novel power quality conditioner based on multiple H-bridges with photovoltaic power. The proposed structure utilizes a hybrid cascaded 81-level converter in series with a PWM converter to achieve a high-voltage and large-capacity power quality conditioner, and photovoltaic power connects with the DC bus side of the hybrid cascaded 81-level converter to reduce active consumption for electric railway. The fundamental voltage of the hybrid cascaded 81-level converter is controlled by the traction network. The active component of the PWM converter output current is controlled by DC link voltage of the hybrid cascaded 81-level converter, and its reactive and harmonic components are controlled by reactive and harmonic currents from the load. The system structure, working principle and control method of the novel power quality regulator are analysed. A single-phase traction system simulation model is built in MATLAB/Simulink. Simulation results are presented to verify the feasibility and effectiveness of the proposed PQC.