Improvement on Command Current Extraction of Railway Static Power Conditioner

The Railway Static Power Conditioner (RPC) can effectively overcome the shortcomings of traditional treatment devices for negative sequence and harmonic compensation, and provide a new idea for the treatment of high-speed railway power quality. The low-pass filter (LPF) plays a key role in the extraction of the command current signal. Traditional command current signal extraction faces challenges in terms of speed and accuracy in balancing techniques. To address this issue, this paper proposes an improved technique to extract the command current signal using the phase shifting capability of the second order generalized integrator (SOGI). Firstly, this method effectively improves the speed and accuracy of the instruction current signal extraction. Secondly, the elimination of low-order harmonic signals allows for higher cutoff frequency of the filter, ensuring both filtering speed and waveform smoothness. Finally, simulation experiments have verified the feasibility and effectiveness of the improved current signal extraction technique.