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Abstract-Wind energy is one of the most available and exploitable forms of renewable energy. Variable speed PMSG based Wind Energy Conversion System (WECS) offers many advantages compared to the fixed speed squirrel cage induction generators such as improved stator output operation at better power factor, no maintenance cost for gear box (as it is directdriven) reduction in weight and losses, higher efficiency and ability to run at low speeds. The elimination of the gear box and brushes can enhance the efficiency of wind turbine by 10%. In this paper a Permanent Magnet Synchronous Generator (PMSG) is modeled whose stator is connected to the constant single phase load (in place of grid) through AC/DC thyristors based rectifier followed by capacitor (dc-link) and DC/DC converter control. Overall arrangement provides constant output to connected load if applied with proper controlling techniques. Hence this proposed wind generation system design can be extended for grid connection also via DC/AC inverter control. Results are simulated and verified in MATLAB/Simulink platform at constant rated (12m/s) and varying (stepped) wind speed for smooth and constant output voltage.

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Many municipalities across the world confront a major problem with waste water treatment. However, Tier-1 and Tier-2 cities have good infrastructure to treat the wastewater, but most of the villages are still facing the problem, because of less resources, the untreated waste water is left to flow on the ground, while travelling it merges with the fresh water bodies, and results in surface and ground water pollution in nearby villages. The devlopment of a pilot size waste water treatment system that efficiently produces water by evaporation and condensation in conjunction with a Fresnel lens solar concentrator is discussed and analysed in this experimental investigation.. Solar radiation setup for waste water treatment consists of Fresnel lens which help in achieving the temperature up to 400oC and then wastewater is being converted into vapour form due to this solar radiation. The evaporated vapour condenses on the surface of the glass and collects in a collecting tank. When compared to a typical wastewater treatment plant, this environmental friendly and sustainable procedure removes organic and bacteriological contaminants from wastewater and, moreover, this chemical-free treatment converts wastewater into reusable form of water with less sludge. The main advantage of this treatment method is, simple to construct and no skilled manpower is required to operate it. Since solar radiation is used as a power source to achieve high temperature therefore, no external power source is required to operate this unit. Results indicate that strength of waste water is reduced by 87%, TDS reduced by 82% as compared to sewage water and Ca, Mg, N, P, Chlorides and Sulphates are reduced by 87%, 91%, 66%, 42%, 92% and 80% respectively. However, the main challenge of this method is low output, but can be improved by various techniques mentioned in the study.

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