Series space vector modulation for multi-level cascaded H-bridge inverters

Abstract

The study presents a series space vector modulation (SVM) method for multi-level cascaded H-bridge inverters. The proposed method is based on construction of multi-level reference voltage vectors from three-level voltage vectors, which are present in the space vector diagram of the multi-level inverter. The proposed approach is compared to the conventional SVM and the carrier-based pulse-width modulation (PWM) ones on 5-, 7-, and 13-level inverters. The implementation of these methods was simulated by Simulink. The simulation results show that implementation of the proposed series SVM is possible. Important advantages of the present series SVM approach against the conventional SVM one are simplicity and easy identification of triangles. Furthermore, it could be easily extended to any n-level inverter.