%0 Journal Article
%A Liu, Qingxiang
%A Rodriguez, Ezequiel
%A Farivar, Glen G.
%A Ceballos, Salvador
%A Townsend, Christopher D.
%A Leyva, Ramon
%A Pou, Josep
%T Discontinuous Modulation of a Cascaded H-Bridge Low-Capacitance StatCom
%D 2022
%@ 0885-8993
%U https://hdl.handle.net/11556/3960
%X This article presents a discontinuous modulation (DM) strategy for static compensators (StatComs) based on a cascaded H-bridge (CHB) converter with a star configuration. The proposed DM strategy considers the capacitor voltage oscillations at twice the fundamental frequency and the effect of zero-sequence voltage injection on the capacitor voltages. Considering these effects is especially important in CHB-StatComs with large capacitor voltage ripples (low-capacitance StatComs), where the assumption of a constant dc-link voltage, which is the basis of conventional DM strategies, does not apply. This article also describes a coherent set of steady-state waveforms for CHB-StatComs under DM. In addition to the well-known benefit of reducing the switching losses, the proposed DM also reduces the dc-link capacitors size and extends the operating range. The viability of the proposed DM strategy is verified experimentally on a small-scale prototype. In addition, simulation results are obtained using a real-scale system to study feasibility of the DM under unbalanced conditions.
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