A Direct Approach to the Positioning of the Reference Vector for Space Vector Modulation

Multilevel converters introduce the possibility of achieving higher power ratings as well as AC voltage quality improvement in the expense of increasing the power circuit and control complexity. Space vector modulation is the preferred PWM technique in three-phase DC/AC multilevel converters. This paper concentrates on a specific matter of the space-vector modulation analysis for diode-clamped multilevel converters, and proposes a direct positioning approach for the reference vector within the corresponding triangle. For an n-level converter, the developed method provides a (n-1)² times 1 complex matrix that locates the exact place of the end of the reference vector. This method reduces the computation time, increasing the accuracy of positioning the switching instants for digital implementation purposes. Optimized C programs were developed to confirm the validity of the proposed method for microprocessor implementation