Grid integrated photovoltaic system with fuzzy based maximum power point tracking control along with harmonic elimination

Efficient extraction and conversion of solar power is an important research area in the field of renewable energy integration. Although, literature is enriched with different power extraction, conversion, and harmonics elimination techniques but still there are problems of maximum power point tracking (MPPT) under partial shading conditions, photovoltaic (PV) mismatching, power fluctuation in steady-state condition, and higher total harmonic distortion (THD) value. The article has two manifolds. First, it proposes a fuzzy embedded MPPT controller to extract the maximum available PV power under time-varying environmental conditions. For that, it utilizes seven linguistic variables and fuzzy sets along with 49 rules base to have reduced power fluctuation and power losses in a steady-state condition, and fast tracking under time-varying temperature and solar irradiance condition. The performance of the proposed fuzzy-logic control (FLC)-49 rules base is compared with FLC-25 rules and perturb & observe based MPPT controllers. Second, for fulfilling the load demands with lower switching losses and THD, particle swarm optimization (PSO) based selective harmonic elimination (SHE) technique is applied on a cascaded half-bridge multilevel inverter. SHE technique utilizes switching angles, which are found by solving the nonlinear transcendental equations obtained by Fourier series expansion of stepped output voltage waveform. For that, the proposed research preferred meta-heuristic techniques of PSO over the classical techniques because of their high convergence rate, short run time, less complexity, and ability to obtain lower THD.