A Single-DC-Source Boost Multilevel Inverter for Dynamic Voltage Restorer Application

Multilevel inverters are used in various applications because of their intrinsic merits. One of the common applications of the multilevel inverters is the power quality (PQ) improvement devices such as the dynamic voltage restorer (DVR). An important in the DVR is how to obtain the DC source required by the inverter used in DVR. As providing the DC voltage source is challenging and costly, the number of required independent DC sources should be minimized. However, most of the multilevel inverters require a number of floating DC sources. In this paper, a 7-level inverter is proposed for the DVR application which requires only one DC source. It should be noted that for the same number of levels, the cascaded H-bridge (CHB) multilevel inverter will require at least (if it is asymmetric) two DC sources. On the other hand, the single-DC-source multilevel inverters such as the flying-capacitor (FC) and the neutral-pint-clamped (NPC) topologies require high number of switches and the DC source utilization factor is low. The proposed multilevel inverter requires one DC source and offers higher number of voltage levels to number of elements. The performance evaluation of the proposed multilevel inverter based DVR is undertaken with the simulations using MATLAB/Simulink.