Experimental results of a three-level voltage source inverter with hysteresis-band current control and hybrid PWM-SVM voltage control

Abstract

This paper presents the experimental results of a diode-clamped three-level inverter used for driving electrical machines. Two different control techniques have been tested for this power converter: a hybrid PWM-SVM voltage control strategy and a double hysteresis-band current control strategy. After checking the good behaviour of these control strategies by simulation results, a small line current THD for a low switching frequency is achieved. Then, a three-level voltage inverter prototype has been developed and both control strategies have been tested upon it. The first one is chosen due to its simplicity, robustness and best ability to filter the current and the second one because a faster and more simple current control can be accomplished. Some simulation results which compare both strategies and some experimental results in the three-level VSI prototype are to be shown in this paper.