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.
