Active suppression of current harmonics on single-phase current-source active rectifier AC side: Proposed approches and their evaluation

In high-power traction applications, low distortion power factor (DPF) is generally desirable under all conditions because although the higher harmonic currents cannot apply active power to loads, they cause higher losses in the transmission line and can disturb track circuits. Operation of single-phase current-source active rectifier (ACSR) under distorted catenary voltage conditions causes distortion of catenary current in terms of high THDi values which from the above reason should be suppressed. In this paper, three approaches in DPF control will be introduced, compared and evaluated from the quality of compensation, stability of operation and complexity point of view. Theoretical expectations of considered compensative strategies and their behavior have been verified by both simulations and large experimental study made on developed small-scale prototype of ACSR of rated power of 7kVA.