Reciprocal sinusoidal vector modulation in matrix converter-based WPT system

Abstract

Matrix converters have gained increasing attention as a promising solution for wireless power transfer (WPT) systems due to their capability for single-stage AC-AC conversion and benefit for high efficiency. However, existing three-phase to single-phase matrix converter-based WPT systems face challenges such as grid-side current harmonics, constrained modulation index, and a relatively high component count, which significantly limit their performance and applicability. This paper proposes a brand-new reciprocal sinusoidal vector modulation, which redefines the existing space vector modulation by substituting the fixed-length current space vector with a time-varying sinusoidal one. This approach leverages the inherent sinusoidal resonant current of WPT systems, enabling low-distortion grid-side current and enhanced robustness under detuned conditions. The reciprocal switching pattern achieves single-cycle reactive power cancellation without requiring additional loop compensation. Moreover, the use of gallium-nitride monolithic bidirectional switches further enhances system performance by reducing conduction losses, shortening commutation intervals, and enabling a higher modulation index. The proposed strategy is validated through theoretical analysis and experimental tests, achieving a total harmonic distortion of 2.26% and a peak efficiency of 93.85%.