Solar energy is becoming a mainstream energy source with considerable attention from analysts these days. The photovoltaic (PV) system’ s output power fluctuates with temperature and sunlight affecting its efficiency. To extract accessible power by PV system, maximum power point tracking (MPPT) method is used. A famous strategy, regularly utilized for simplicity and low cost, is the Perturb and observe (PO) algorithm. However, there are a few downsides of PO algorithm, which result in power loss and low efficiency. We evaluate the performance of the conventional PO against some of its enhancements, specially a recent PO-variant, for MPPT. Experiments are conducted at different irradiances and temperature levels in two ways: with load and with battery, by conventional PO and its variants. Outlining strategy to reach optima and stability of the methods are discussed. The PO variants are rated from view-points of stability, accuracy, post-MPP oscillations and tracking speed. The recommendations can prove to be fruitful for the practitioners working with MPPT in PV solar systems using PO algorithms. The validation of simulation results has been made using the real time experimental results. The new PO-variant appears to be a reliable computing algorithm for MPPT in solar PV systems.

Z-Source Inverter (ZSI) is a new topology of power converter, especially a DC-AC converter, at a very interesting power level. For instance, it only uses a single-stage power converter with a buck-boost characteristic. This work introduced a combination of a solar system and a ZSI based dynamic voltage restorer to reduce the voltage swell and harmonics under sudden addition of a balanced three-phase nonlinear load. This paper focused on Perturb and observe (P&O) algorithm to automatically determine the operating voltage of PV systems that would produce maximum power output. The proposed ZSI based dynamic voltage restorer was designed and modeled by using MATLAB/SIMULINK. The outcomes were compared with those of conventional dynamic voltage restorers equipped with voltage and current source inverters.

Maximum power point tracking controller is essential to obtain the maximum power from a solar array in the photovoltaic systems as the PV power module varies with the temperature and solar irradiation. In this paper, several methods for the MPPT of the PV systems are discussed and it can to be used as a Helpful reference for the upcoming MPPT user in the PV applications.

In this research, a single-phase multilevel inverter with a reduced number of switches and driver circuits is introduced for analysis in photovoltaic systems. The proposed multilevel inverter consists of two parts, basic circuit, and H-bridge, which are responsible for generating voltage levels and symmetry of voltage levels (positive and negative), respectively. The proposed basic circuit in this paper consists of six unidirectional switches and three input sources and doesn’ t use any capacitors or diodes, which reduces the volume and complexity of the control system. In this paper, the seven-level proposed structure is simulated in the MATLAB/Simulink software and the utilized modulation to generate the output voltage levels is level shifted pulse width modulation. Moreover, photovoltaic systems are exploited to supply the proposed inverter’ s input sources, which work with Perturb and observe algorithm at the maximum power point. In the simulation section, the voltage, current, power waveforms of the photovoltaic system, and the voltage of the proposed inverter input sources are demonstrated, and the voltage and current waveforms of the inverter for different conditions such as radiation and modulation index change are given. Finally, to show the merits and features of the proposed topology, the inverter is compared with some recent symmetrical structures in terms of the number of components and the rated voltage of the switches.

In recent year's renewable energy sources have become a useful alternative for the power generation. The power of photovoltaic is nonlinear function of its voltage and current. It is necessary to maintain the operation point of photovoltaic in order to get the maximum power point (MPP) in various solar intensity. Fuzzy logic controller has advantage in handling non-linear system. Maximum power point trackers are so important in photovoltaic systems to increase their efficiency.Many methods have been proposed to achieve the maximum power that the PV modules. This paper proposed an intelligent method for MPPT based on fuzzy logic controller. The system consists of a photovoltaic solar module connected to a DC-DC Boost converter and the fuzzy logic controller for controlling on/off time of MOSFET switch of a boost converter. The proposed MPPT controller for grid-connected photovoltaic system is tested using model designed by Matlab/Simulink program. Comparison of different performance parameters such as: tracking efficiency and response time of the system shows that the proposed method gives higher efficiency and better performance than the conventional Perturbation and observation method.