Analyzing power quality issues of wind power plants in puttalam

Abstract

Wind Power development has become a booming industry due to its advantages over conventional thermal power sources. However, wind is considered as an intermittent source in terms of power quality as wind turbines have an uneven power generation following natural variations of wind. Power quality (PQ) is an important issue for electricity consumers at all levels of usage, particularly industrial sector as PQ disturbances ultimately lead to huge economic losses and safety concerns. The research objectives are; to study on major power quality issues associated with four wind plants in Puttalam, propose suitable PQ improving methods and to identify the most suitable wind technology in view of power quality. Project scope includes measurement of electrical parameters at each plant, analysis of parameters based on “IEC 61400-21” and “Grid Connection Requirement” published by Ceylon Electricity Board, study on mitigation techniques, computer modeling and simulation in MATLAB/SIMULINK environment to investigate harmonic mitigation. For each power quality aspect, a set of norms and marginal values were set to evaluate each wind plant’s performance. There are four distinct wind technologies and three of them are available in Sri Lanka. Out of these technologies, Wind Turbine type “C” which employs a Doubly-Fed Induction Generator with a partial scale power converter shows the best power quality characteristics. From Measurements and Data Analysis it was concluded that, none of the investigated plants adhere to power quality requirements of the grid code. Neither the utility (CEB) nor the Wind Power Producers pay adequate attention on these violations. It is recommended to pay more attention on PQ deviations. Systems must be developed to continuously monitor PQ parameters and take necessary actions to keep them within specified levels. Further, hybrid filters to reduce harmonic distortion and Dynamic Voltage Restorers to mitigate voltage sags are proposed for WPPs under study.