Design of a New Single-Phase Multilevel Voltage Source Inverter Based on Series Connection of Basic Units

Abstract

A novel multilevel inverter (MLI) structure is introduced in this paper. Since one of the crucial factors in designing and usability of an MLIs is the ratio of the total number of semiconductor devices to the output voltage levels, this ratio is reduced in the proposed structure in comparison to the conventional MLIs. The less utilized devices mean, the lower the cost of implementation, size of the system, required installation area, control complexity, and also higher reliability. The proposed structure is modular and can operate in two modes (symmetric and asymmetric), which are discussed in this paper. To express the worthiness of the presented structure, a comparison with the conventional cascade H-bridge MLI is presented. Also, the nearest level control (NLC) switching technique is applied to generate the output voltage waveform. The computer-aided simulation is made to prove the feasibility and performance of the suggested structure. The analytical results are carried out by the Simulink of MATLAB.