A Simplified Space Vector Pulse Density Modulation Scheme Without Coordinate Transformation and Sector Identification

A simplified space vector pulse density modulation (SVPDM) scheme for any odd-level inverter-based induction motor drive is proposed in this article. The control strategy uses three sigma delta modulators, wherein the reference space vector is vector quantized to generate the output switching vectors. The switching vectors for the inverters are derived without coordinate transformation and sector identification in this scheme, making the algorithm computationally simpler. The proposed SVPDM scheme retains the advantages over SVPWM scheme such as freedom from minimum pulsewidth problem, improved spectral features, convenience of digital implementation, avoidance of complex timing calculations, and less annoying acoustic noise pattern of motor. The scheme is experimentally verified for an open-end winding-based five-level induction motor drive. The performance of the proposed scheme is compared with the deterministic and nondeterministic schemes and the results obtained substantiate the efficiency of proposed scheme.