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 600 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.