In this study, a multilevel inverter was designed and implemented to operate a stand-alone solar photovoltaic system. The proposed system uses pulse-width modulation (PWM) in the multilevel inverter to convert DC voltage from battery storage to supply AC loads. In the PWM method, the effectiveness of eliminating low-order harmonics in the inverter output voltage is studied and compared to that of the sinusoidal PWM method. This work also uses adaptive neuro fuzzy inference (ANFIS) to predict the optimum modulation index and switch angles required for a five level cascaded H-bridge inverter with improved inverter output voltage. The data set for the ANFIS-based analysis was obtained with the Newton-Raphson (NR) method. The proposed predictive method is more convincing than other techniques in providing all possible solutions with any random initial guess and for any number of levels of a multilevel inverter. The simulation results prove that the lower-order harmonics are eliminated using the optimum modulation index and switching angles. An experimental system was implemented to demonstrate the effectiveness of the proposed system.

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Abstract-A Wind Generator System that employs a boost chopper and a permanent magnet synchronous generator is studied. By replacing the main circuit of generator and boost chopper with the equivalent circuit, the power and DC output voltage are obtained as a function of duty ratio of the boost chopper and generator rotational frequency. Maximum power from the generator characterized by the load and optimum duty ratio is theoretically determined. Results of MATLAB/ SIMULINK simulation are presented.

This paper presents Maximum Power PointControl for variable speed wind turbine driven permanentmagnet generator. The wind turbine generator is operated such that the rotor speed varies according to wind speed to adjust the duty cycle of power converter and maximizes Wind Energy Conversion System (WECS) efficiency. The maximum power point for each speed value is traced using Maximum Power Point Tracking (MPPT) algorithm. The rotating speed of permanent-magnet generator should be adjusted in the real time to capture maximum wind power. The system includes the wind-turbine, permanent-magnet generator (PMG), three-phase rectifier, boost chopper, inverter and load. The control parameter is the duty cycle of the chopper. PMG is made to operate at variable speed to achieve good performance. The entire WECS model consists of wind turbine model, PMG model and power converters model. The MATLAB / SIMULINK is used for simulation and the results are compared with laboratory setup.