Swarm Optimization-Based Modified Selective Harmonic Elimination PWM Technique Application in Symmetrical H-Bridge Type Multilevel Inverters

The problem of elimination of harmonics and the need of a large number of switches in multilevel inverters (MLIs) have been a hot topic of research over the last decades. In this paper, a new variant swarm optimization (SO) based selective harmonic elimination (SHE) technique is described to minimize harmonics in MLIs, which is a complex optimization problem involving non-linear transcendental equation. Optimum switching angles are calculated by the proposed algorithms considering minimum total harmonic distortion (THD) and the best results are taken for controlling the operation of MLIs. The performance of the proposed algorithm is compared with the genetic algorithm (GA). Conventional MLIs have some disadvantages such as the requirement of a large number of circuit components, complex control, and voltage balancing problems. A novel seven-level reduced switch multilevel inverter (RS MLI) is proposed in this paper to recoup the need of a large number of switches. Matlab/Simulink software is used for the simulation of two symmetrical topologies, i.e., a seven-level cascaded H-bridge multilevel inverter (CHB MLI) and a seven-level (RS MLI). Simulation results are validated by developing a prototype of both MLIs. The enhancement of the output voltage waveform confirms the effectiveness of the proposed SO SHE approach

Selected Harmonic Elimination for Cascaded Multilevel Inverter Based on Photovoltaic with Fuzzy Logic Control Maximum Power Point Tracking Technique

This paper describes the work performed on a single phase 9-level cascaded H-Bridge multilevel inverter (CHB-MLI) for photovoltaic (PV) power generation, using two methods of maximum power point tracking (MPPT)—namely fuzzy logic controller (FLC) and perturbation & observation (P&O). The MPPT scheme is used to extract maximum power from solar PV cells. PV cell temperature and solar irradiation are input quantities and the two used methods estimate the optimum duty cycle to ensure DC-DC boost converter maximum output. This paper also compares the results obtained by the work performed on CHB-MLI with DC-DC boost converter using FLC based MPPT controller to that of results obtained with the conventional P&O method. The fuzzy logic controller works with imprecise inputs, it does not need an accurate mathematical model and it can handle nonlinearity well. Besides, fuzzy is more robust as compared to the conventional non-linear controller. The genetic algorithm (GA) based Selective Harmonic Elimination (SHE) technique is also applied to CHB-MLI for the elimination of harmonics from the output voltage. In the work reported in this paper on PV inverter making use of the Fuzzy MPPT technique, the obtained total harmonic distortion (THD) of the output voltage without filter circuit and with filter circuit are within IEEE standard 519