Current compensation control strategy of railway power regulator based on MMC

In order to solve the problem of negative sequence, harmonic and reactive power in traction power supply system, a current compensation control strategy based on modular multilevel railway power conditioner is designed. First, the structure and compensation principle of MMC-RPC was introduced, aiming at the problem of poor effect and phase lag when low-pass filter is used to extract DC component of instantaneous power, DC component extractor based on second-order generalized integrator（SOGI） is designed, which can obtain DC component more quickly and effectively. Then the proportional complex integral controller is used to control the output current of MMC to achieve comprehensive control of power quality of traction power supply system. Finally, the simulation results confirm that the control strategy proposed in this paper can achieve good negative sequence and harmonic compensation.