Recent Predictive Control Strategies Applied to Flying Capacitor Multilevel Inverters

Predictive control is a new control strategy that has been applied to control power electronics applications, in the last decades. Many researches are working on the improvement of this control method such as reduction of computations cost, increasing accuracy, etc. This paper introduces some of the most challenges and trends through an overview on papers that were published recently.

I. Introduction

Flying capacitor multilevel converters [1] have many important attributes for medium voltage applications. The main advantage of these converters are, the natural self-balancing of capacitors, no need to use transformer and keeping the capacitors voltages in their appropriate values [1], [2]. These converters can generate a high number of levels by increasing cells count (capacitors and switches) [3]. The capacitors voltage are balanced naturally and do not require extra control feedback. The natural balancing occurs when the value of the average capacitors currents tend to zero. Therefore, each cell is controlled in a same duty cycle with a phase changing progress. Usually, an RLC filter is connected to the output load to reduce the signal errors and increase the balancing speed of capacitors [4].