Space vector modulation scheme with direct Vector Quantization for any N-level voltage source inverter

A new space vector based spread spectrum modulation scheme for any general N-level voltage source inverter is proposed in this paper. The proposed scheme uses the sigma delta modulation with quantizer implemented by the principle of Vector Quantization. The N-level inverter vector space is divided into different Voronoi regions around the inverter switching vectors. A new method is proposed for directly quantizing the reference space vector to the inverter switching vectors. 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 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.