Power Loss Investigation for 13-level Cascaded H-Bridge Multilevel Inverter

In recent years, voltage source multilevel inverters are being applied extensively in industry as they have many advantages compared to conventional two level inverters. Some of these advantages such as higher output voltage at low switching frequency, low voltage stress (dv/dt), lower Total Harmonic Distortion (THD), less Electro-Magnetic Interference (EMI), smaller output filter and higher fundamental output. However, the evaluation of multilevel inverter losses is much more complicated compared to two level inverters and required more computations burdens. This study presents an on-line model for precise evaluation of conduction and switching losses in cascaded H-bridge multilevel inverter. The model is simple and efficient and gives clear and easy to implement procedure of loss calculation. A single-phase 13-level cascaded H-bridge with IGBT's as switching devices has been considered as a case study of the proposed model. The inverter has been controlled by applying SHE in which the switching angles were determined using the Genetic Algorithm (GA). The modelling and simulation has been conducted using MATLAB-SIMULINK software.