High-performance current control techniques for application to multilevel high-power voltage source inverters

Several high-performance current control techniques are developed for applications to multilevel high-power voltage source inverters (VSIs). The logical sequence of the design choices is described, resulting in a very robust and reliable control system that allows an adequate switching optimization, excellent dynamic responses, and high accuracy in steady-state operation. The advantages of using various accessible DC potentials are fully exploited. The validity of the proposed schemes has been confirmed by digital simulations involving the generation of five-level voltage waveforms; however, the current control strategies developed can easily be extended to any multilevel inverter structure, even in the case of n-level voltage waveforms and three-phase systems