A General Space-Vector Modulation Technique for multilevel NPC Inverter

This paper presents a general and yet fast multilevel space-vector modulation technique, based on orientation of reference point in terms of hexagon lines. The main advantage of the proposed algorithm is the reduced volume of calculations that consequently makes it possible for implementing on cheaper microprocessors. The introduced technique in finding the reference vector location is extended to an n-level inverter while keeping its simplicity in computations. The improved technique is fully elaborated for a 3-level NPC inverter and then explained how to generalize for n-level inverters. Eventually it is implemented on a 3-level NPC inverter feeding linear/nonlinear and balanced/unbalanced loads all in Matlab/Simulink environment. Results are shown and discussed to prove the good dynamic performance of the introduced SVM approach in producing appropriate switching pulses for NPC inverter semiconductor devices.