Simulation of Five Level Diode Clamped Multilevel Inverter

The power electronics device which converts DC power to AC power at required output voltage and frequency level is known as inverter. The voltage source inverters produce an output voltage or a current with levels either 0 or +ve or-ve V dc. They are known as two-level inverters. Multilevel inverter is to synthesize a near sinusoidal voltage from several levels of dc voltages. Multilevel inverter has advantage like minimum harmonic distortion. Multi-level inverters are emerging as the new breed of power converter options for high power applications. They typically synthesize the stair-case voltage waveform (from several dc sources) which has reduced harmonic content. Multi-level inverters have many attractive features, high voltage capability, reduced common mode voltages near sinusoidal outputs, low dv/dt, and smaller or even no output filter; sometimes no transformer is required at the input side, called the transformer-less solution, making them suitable for high power applications In this paper a 5-level Diode clamped multilevel inverter is developed by IGBTS using Simulink. Gating signals for these IGBTS have been generated by designing comparators. In order to maintain the different voltage levels at appropriate intervals, the conduction time intervals of IGBT have been maintained by controlling the pulse width of gating pulses[6] (by varying the reference signals magnitude of the comparator). The simulation results for 5-level and THD for the output have been identified by MATLAB/SIMULINK

Design and Analysis of Multilevel Inverter with Reduced Number of Switches using Multicarrier SPWM Techniques

Multi-level inverter has been widely accepted for high voltage applications. Their performance is highly superior to that of conventional two level inverter due to reduced harmonic distortion, lower electromagnetic interference and higher dc link voltages. Multi-level inverter (MLI) has some disadvantages such as increased number of components, complex pulse width modulation control method, and voltage-balancing problem. In order to increase the level of the output, the numbers of switches are increased and losses and complexity also increased. Hence to reduce these losses and complexity, a new topology is designed in this project i.e. Multi-level inverter (MLI) with reduced number of switches. A new inverter topology has been proposed which has superior features over conventional topologies in terms of the required power switches and isolated dc supplies, control requirements and reliability. In the mentioned topology, the switching operation is separated into high- and low-frequency parts. Design and simulation analysis of new 7 level inverter topology with multicarrier spwm techniques is presented in this project thesis using MATLAB/SIMULIN