An active DC bus-capacitor harmonic-current reduction method is proposed for a two-level back-to-back converter. According to the fundamental frequency of the converters and the predefined look-up tables, the frequency and phase of the carrier signals are tuned, so that the phase of the most significant DC-bus harmonic currents from each converter is in phase, and the capacitor harmonic current is minimized. The feasibility of the proposed method is verified by simulation.
