Modulated Model Predictive Control With Branch and Band Scheme for Unbalanced Load Compensation by MMCC-STATCOM

This article presents a novel modulated model-predictive control (MMPC) scheme for modular multilevel cascaded converter-based static synchronous compensator (STATCOMs) (MMCC-STATCOMs) to compensate unbalanced load current and regulate reactive power flow. By adding common-mode voltage (CMV) the phase-voltages of star-connected MMCC model, method allows natural injection nonsinusoidal neutral point converter, hence achieving interphase cluster balance. Moreover, imposed CMV is shown extend operating ranges MMCC-STATCOMs when used negative sequence compensation. The proposed MMPC incorporates modified branch bound algorithm optimize per-phase switch duty ratios. It be computationally more efficient compared schemes using optimal level combined with sorting schemes. Experimental results different weighting factors confirm effectiveness this favorably conventional injecting only sinusoidal zero-sequence voltage.