A new space vector modulation scheme for any N-level voltage source inverter which directly quantizes the reference space vector

A new space vector based sigma delta modulation scheme for any general N-level voltage source inverter which directly quantizes the reference space vector is proposed in this paper. The proposed scheme uses the sigma delta modulation with quantizer implemented by the principle of Space Vector Quantization. A new scheme is proposed for directly quantizing the reference space vector to the multilevel inverter switching vectors without mapping it into 2-level inverter vector space. The property of integer values of the inverter switching vectors in 60° coordinates is utilized for the direct Vector Quantization of instantaneous reference voltage space vector. The multilevel inverter vector space is divided into different parallelogram to define Voronoi regions around the inverter switching vectors in the proposed space vector quantizer. The proposed scheme is implemented for 5-level inverter realized by an open-end-winding induction motor fed with two 3-level inverter from either side having symmetrical dc-link voltages and results are presented.