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Grid connected PV systems is gaining popular in the recent past as a viable and attractive alternative source of power in the urban areas to meet the increasing energy demand. This paper presents a comprehensive review of Maximum Power Point Tracking (MPPT) techniques employed in such grid tied PV systems. A classification of different MPPT techniques based on topology of grid interface is presented. Also the simulation and detailed performance analysis of the incremental conductance (INC) method with d (delta) control has been presented. In this work a single stage grid tied PV system has been considered due to its advantages, for the performance analysis of the INC technique. Simulation of this single stage Grid tied PV Inverter is done using MATLAB/ Simulink. Different cases have been considered for simulation and performance indices measurement, under varying irradiation and temperature conditions. Also the MPPT control under varying grid voltages has also been analyzed. The Simulation results have been presented in detail and the results depicts that d control modified Incremental conductance MPPT works for different values of irradiations, temperature and grid parameters variation and are presented in this work.

This paper use a suitable power converter topology and design a suitable controller for a Wind Energy Conversion system with Permanent Magnet Synchronous Generator (PMSG) for stand alone and grid integrated operations. The present work presents the system in which a PMSG feeds an isolated load through a closed loop boost converter. The output voltage and frequency of the PMSG is variable in nature due to non uniform wind velocities and is not synchronized with the grid frequency. In order to condition and feed it to grid we need power electronic interface. The variable ac output is rectified by a diode rectifier and maintained constant by a boost converter. The boost converter is provided with a closed loop feedback control, which is designed using PI controller. In this controller the output voltage is continuously sensed and duty ratio of the switch is varied to maintain the DC link voltage constant. The converter output is fed to three phase inverter which employs a sine PWM technique, the output of which is fed to the load. The power converters and together with independent control systems can effectively improve the output voltage and frequency of the wind PMSG feeding an isolated load. The whole system is simulated using MATLAB/ Simulink and the results are presented to demonstrate the veracity of the developed control scheme.

The 3-Φ self-excited induction generator driven by wind energy source is suitable for stand-alone applications. For such an application, the minimum excitation capacitance required for self-excitation of 3-Φ induction generator is taken up in this work and the detailed analysis is carried out to determine the range of wind speed variation and consumer demand for the designed capacitance value. An electronic load controller is designed to maintain the load voltage constant for these variations. The excess power resulting as a consequence of rise in load voltage due to variation in load is pumped to dump load. Instead of wasting the power to the dump load, a battery is used to utilize the power. Exhaustive simulations have been carried out for such a scheme and the results have been presented in this paper.

A control strategy for hybrid dispersed power generators based on Photo-voltaic array and wind driven induction generator integrated with residential load and grid is investigated in this paper. The state space model developed for this grid integrated hybrid scheme is used for the design of controller topology involving nested power, voltage and current loop and implemented in MATLAB\Simpower platform. The operation of the scheme is investigated for varying power demands from the customer side and for varying irradiations of PV array with constant wind speed by independent control of real and reactive power. The inverter terminal voltage and PV array voltages are calculated on the basis of parameter estimation and thus voltage sensors can be avoided. The simulation results clearly indicates that the developed controller is able to maintain constant voltage at Point of common coupling (PCC) and deliver current at UPF with good dynamic response for varying irradiations and also nullifies the effect of voltage swell and sag at PCC.