Extension of PWM space vector technique for multilevel current-controlled voltage source inverters

The space vector technique is widely used to shape the inverter output currents. In order to improve the inverter performance, especially in high-voltage applications, multilevel inverters structures are utilized. The conventional space vector technique cannot be applied to control the multilevel inverter output currents. In this paper, a generalized method for controlling the output currents of this type of inverter is introduced. As a case study, the discrete-time current control of a three-phase voltage-source inverter is discussed. Inverter topologies are simulated using switching function concepts. Computer simulations demonstrate the validity of the introduced control strategy and its generalized rules for multilevel inverters.