Power Quality Evaluation in a Microgrid Implementation

The implementation of microgrids including distributed energy resources is an efficient energy solution with regard to saving financial and environmental resources and assisting in the stability and reliability of the power system. However, some unwanted effects such as voltage fluctuations, unbalance, frequency changes and harmonic distortions due to the Distributed Renewable Generations (DRGs) and non-linear loads operations may affect the power quality within the microgrid, making necessary studies and analyzes, to maintain the quality indicators at satisfactory levels. The power quality in systems with distributed generation (DG) is discussed in papers mostly through mathematical and computational modeling and these do not allow the consideration of equipment operation characteristics. It is therefore necessary to complement the theoretical studies with experimental results [1]. This study aims to evaluate the power quality at the connection point where a microgrid was installed on a university campus to characterize the energy scenario to which the microgrid will be submitted. It was found that the system had a monthly average of22.9 voltage sag events, 1.8 interruptions per month, 2.37% of total voltage harmonic distortion, 0.283% of voltage fluctuation, and unbalance below 0.5%.