Maximum Power Point Tracking for Cascaded PV-Converter Modules Using Two-Stage Particle Swarm Optimization

The paper presents a novel two-stage particle swarm optimization (PSO) for the maximum power point tracking (MPPT) control of a PV system consisting of cascaded PV-converter modules, under partial shading conditions (PSCs). In this scheme, the grouping method of the shuffled frog leaping algorithm (SFLA) is incorporated with the basic PSO algorithm, ensuring fast and accurate searching of the global extremum. An adaptive speed factor is also introduced to improve its convergence speed. A PWM algorithm enabling permuted switching of the PV sources is applied. The method enables this PV system to achieve the maximum power generation for any number of PV and converter modules. Simulation studies of the proposed MPPT scheme are performed on a system having two chained PV buck-converter modules and a dc-ac H-bridge connected at its terminals for supplying an AC load. The results show that this type of PV system allows each module to achieve the maximum power generation according its illumination level without affecting the others, and the proposed new control method gives significantly higher power output compared with the conventional P&O and PSO methods

A novel single-phase thirteen level inverter for photovoltaic application

This paper proposed a Single-Phase 13-level inverter with voltage control method using semiconductor power devices for photovoltaic systems. The multilevel voltage source inverters unique configuration allows them to make high voltages with low harmonics without use of transformers or series associated synchronized switching devices. The general role of the multilevel inverter is to synthesize a desired voltage from several levels of dc voltages for these reason multilevel inverters can simply provide the high power required of a large electric drives. The proposed inverter system gives superior voltage regulation, smooth results and efficiency compared to multi-level inverters. The inverter is capable of producing thirteen levels of output voltage levels (Vpv, 5Vpv/6, 4Vpv/6, 3Vpv/6, 2Vpv/6, Vpv/6, 0, -Vpv/6, -2Vpv/6, -3Vpv/6, -4Vpv/6, -5Vpv/6, -Vpv). The proposed inverter was demonstrated by using simulation of MATLAB/SIMULINK software