Implementation of digital FCS-MP controller for a three-phase inverter

Abstract

In this paper, a digital current control of a three-phase four-leg inverter based on predictive cost function is studied. Inverters are important for power electronics applications in three-phase four-wire systems, such as active power filters and uninterruptible power supplies. There are many methods for control of inverters, such as pulse-width modulation and three-dimensional space vector modulation. These methods are complex. In this paper, a simple way for current control of a three-phase four-leg inverter is presented. Here, by using a predictive cost function and fixed-point computations, the optimal switching state to be applied in the next sampling is selected. Finally, to evaluate the accuracy of the fixed-point computations, several cases for balanced and unbalanced loading conditions are verified. In each case, the parameter that measured to confirm computation accuracy is total harmonic distortion.