Suppression of Harmonics of Multi-Level Converter applied for Back-to-Back HVdc Link

Abstract

This paper proposes new pulse width control to suppress the higher harmonics of the output of a multilevel converter applied for back-to-back (BTB) HVdc Link. A multilevel converter can reduce the snubber loss and the switching loss since it decreases the number of series connected switching device and the switching frequency. The staircase voltage waveform is expected to be able to suppress the higher harmonics. We investigated the condition necessary to suppress the higher harmonics and proposes the control method of the fundamental voltage amplitude. We show the effectiveness of the proposed control method from the simulation results using Alternative Transient Program (ATP).