A Space Vector Modulation Control Algorithm for VSI Multi-Level Converters

In this paper a novel modular digital control algorithm for multi level inverters is introduced and discussed. This algorithm is essentially based on the duty cycle expression and allows a great simplification, because of its modularity and its simple implementation. The algorithm is particularly suitable for the Multi Point Clamped (MPC) inverters with no constraint on the number of the voltage levels and results faster than the most recent solutions proposed in literature. The modulation techniques considered in the paper are the sub oscillation PWM and, above all, the Space Vector Modulation (SVM), but the proposed algorithm may be employed for the main carrier based PWM control techniques including the “Zero sequence injection”. Simulation of a MPC inverters, controlled with the proposed algorithm, have been made with the help of the MATLAB-SIMULINK® package. For these simulations a mathematical model already known in literature, but adapted to be used within the MATLAB-SIMULINK® environment, has been used. The simulation results show the effectiveness of the MPC model formulation and of the proposed control algorithm.