A Simplified Space Vector Overmodulation Strategy for PMSM Drive System

A simplified space-vector pulse width modulation based overmodulation technique for permanent magnet synchronous motor drive system is proposed. There are two overmodulation modes in the proposed method. The duties of two modes for overmodulation region in modulation hexagon sector one are generated by simplified linear formulae. With simplified linear duty generating formulae, the computational burden is relatively smaller than conventional overmodulation method. DC bus voltage is maximum utilized and modulation index can be extended to the maximum value. The transition between linear modulation and overmodulation, and overmodulation and six-step operation is smooth. The results of verification on a PMSM platform demonstrate the effectiveness of the proposed method.