Abstract: Wind energy as a renewable energy source continues to be a better alternative to fossil-fuel based generation due to its low cost and environmental benefits. While considerable research efforts have been focused on modeling and control of grid connected variable speed squirrel cage induction generator (SCIG) wind energy conversion systems (WECS), comprehensive models for grid integration studies have been almost non-existent. This paper presents the detail modeling, control and analysis of a grid-connected 2.25-MW variable speed SCIG based WECS that can be utilized for grid integration studies. The presented WECS model consists of a pitch regulated wind turbine connected to a SCIG through a gear box. Then, a full-capacity power electronic converter with maximum power point tracking (MPPT), dc bus voltage regulation and power factor correction, connects the SCIG to the grid. The power converter system comprises of back to back two-level voltage source converters linked through a dc-link capacitor. The generator and grid-side converters are controlled using indirect rotor field-oriented control (IR-FOC) and voltage-oriented control (VOC) respectively. The overall system is simulated in MATLAB/Simulink for a varying wind speed. Results show that the presented model is adequate and efficient in the representation of a variable speed SCIG WECS. In addition, the model meets all of the system performance objectives while simultaneously meeting all of the control objectives.Abstract: Wind energy as a renewable energy source continues to be a better alternative to fossil-fuel based generation due to its low cost and environmental benefits. While considerable research efforts have been focused on modeling and control of grid connected variable speed squirrel cage induction generator (SCIG) wind energy conversion systems (WECS), c...Show More
Abstract: Micro hydropower helps the rural areas to supply power with off grid electrification. This study deals with the design of micro hydropower scheme in Gobecho kebele, Genale Dawa river basin, Ethiopia. The site for the construction of diversion weir is located upstream of the Ganga river in the kebele. The design were implemented based on the available hydrological data collected from 1991 to 2020 river discharge at different stations by selecting the one, which is near to the Gobecho catchment. Ererti is a station geographically near to Gobecho catchment by using GIS 10.7 application. The Gobecho peak probable discharge of 3.503m3/s is computed using log normal distribution after L-moment analysis. Based on this peak discharge, vertical drop weir and components of headwork structure designed and provided relevant dimensions. The proposed vertical drop weir has a height of 0.703m, crest length 10m and the design flow for a hydropower scheme is 0.132m3/s estimated by FDC. The water passes through trapezoidal power canal of a 0.35m width and a 0.43 height to a forebay tank. A forebay of size 9 × 1.3 × 1.7 is provided at the end of the power canal. Moreover, the water leads from forebay to a 0.24m diameter of penstock running one unit turbine and capacity of 25kw. The selected type of turbine for proposed plant is cross flow turbine. Finally, the quantity of calculated estimate cost is 50,000 USD and the B/C ratio of 1.48 provided for this micro hydropower project.Abstract: Micro hydropower helps the rural areas to supply power with off grid electrification. This study deals with the design of micro hydropower scheme in Gobecho kebele, Genale Dawa river basin, Ethiopia. The site for the construction of diversion weir is located upstream of the Ganga river in the kebele. The design were implemented based on the availab...Show More