A Novel Three-phase Multilevel Inverter with Reduced Number of IGBTs, Developed for Drive Application

This paper exposes a new three-phase multilevel inverter (MLI) suitable for electrical motor drive applications, which consists of a cascade connection of basic cells. In this proposed three-phase topology, the ratio of the utilized power components against the generated levels is decremented that leads to decrement the cost and complexity of the converter. The converter is devoted to speed control of the induction motor (IM). One of the methods for speed control of the IM is the constant Volt-per-Hertz (constant V/f) control method. The multicarrier level-shifted pulse width modulation (LS-PWM) is applied to the new structure to obtain a high-quality output voltage, which helps to control the amplitude and frequency of output voltage by the sinusoidal reference signal. The simulation is carried out in MATLAB/SIMULINK environment. Furthermore, the simulation result and steady-state torque-time characteristics are presented. Besides, the comparison of introduced structure with some conventional MLIs is shown in terms of the number of switches.