Photovoltaic (PV) model is used in a simulation study to validate the system design of a PV system. This paper presents a step-by-step (detailed modeling) procedure for the simulation of photovoltaic modules with numerical values, using Matlab/Simulink software package. The proposed model is developed based on the mathematical model of the PV module, which is based on that of an elementary PV solar cell employing One-diode equivalent circuit. A particular Polycrystalline PV module is selected for the analysis of the developed model. The essential parameters required for modeling the system are taken from datasheets. The output current and power characteristic curves highly depend on some climatic factors such as solar radiation and temperature, are obtained by simulation for the selected module with the output power of 250 W and discussed.

For the instability and the nonlinearity, complexity and difficult problem a state feedback method is proposed to cancel the nonlinearities and control of three-phase photovoltaic inverter. The nonlinear model is linearized using feedback linearization, state feedback law and state transform. The steady state has applied for simplified the state feedback law, make the closed-loop dynamics in equivalent linear subsystem, and then applies the input output feedback linearization control. This nonlinear state model transforms the d-q reference into an equivalent linear system, the pole placement control loop technique is applied to separate the control and make the closed-loop system pole placed in the desired location. The system is composed of one photovoltaic array, capacitive DC-link, three-phase inverter connected to the grid assumed to be in phase with the inductor current. The capacitor voltage is regulated and controlled to reduce the harmonic in the input of the inverter and to assure the stability of the photovoltaic system. In order to analyze the closed-loop dynamics of the subsystem the incremental conductance algorithm is used to optimize and track the maximum power from the photovoltaic generator under varying temperature and irradiance conditions. The algorithm shown better performances and effectiveness compared to other techniques. It can respond quickly to changes in the external environment and make sure the photovoltaic array is always working at the point maximum and improve the efficiency, the stability of single stage three-phase photovoltaic grid-connected. According to the simulation results this controller is globally stable.