No abstract

This paper presents a unique approach towards the reduction of steps employed in conversion of power produced by a photovoltaic energy system. When a Photovoltaic system feeds an ac load, the power conditioning system of a Photovoltaic energy conversion system consists of a boost converter at the first stage to boost up the direct current (dc) supply, and an inverter to convert this boosted supply to alternating current (ac) at the second stage. But in this conventional system, losses happen at both the stage which makes the whole system to have low efficiency. The proposed approach in this paper has only one stage conversion. In this single step conversion the direct current supply is boosted and converted to alternating current with the help of a single inverter circuit. This process of power conditioning is carried out with respect to the load connected as well to the maximum power with respect to the variant irradiation and temperature condition. The load connected to the system is tested under varying environmental conditions of the photovoltaic system. Nature of output power from the system is studied by varying the irradiation and temperature of the photovoltaic array.

This paper emphasizes on proposing a cost effective photovoltaic (PV)

The wind turbine generator considered in this work employs a directdriven (Without gearbox) PMSG, which is directly coupled to the wind turbine and connected to the electric grid through the power conditioning system (PCS). The stator windings of the PMSG are directly connected to the PCS composed of a fullscale power converter built using a back-to-back AC/DC/AC power converter topology which includes a three-phase rectifier bridge (AC/DC conversion), a DC/DC converter and a grid-side converter with an intermediate DC link (DC/AC conversion). A maximum power point tracking algorithm is used to track the maximum power output to increase the power conversion efficiency in the system. Thus the generator produces the maximum power continuously.Keywords PMSG Á MPPT Á Wind energy Á Power conditioning system (PCS) IntroductionWind-powered machines have been used by humans for thousands of years. Until the 20th century the application of wind power is limited. Now-a-days wind energy is considered as feasible source of renewable energy. The reason is that it is considered inexhaustible and can be converted easily into electrical energy through various wind energy conversion systems.Previously constant speed turbines are used for the conversion. Due to the fixedspeed operation for constant speed turbines, all the variations in the wind speed are transmitted as fluctuations in the mechanical torque and then as fluctuations in the electrical power grid. This can be avoided by the use of variable-speed wind turbine

No abstract