Increasing renewable energy penetration in harmonically polluted distribution grids using passive filtering: a comparative assessment of common filter types.

Increasing the penetration level (PL) of renewable energy in the distribution power grids has the potential of fulfilling growing energy demands and curtailing fossil fuel usage along with its economic and technical benefits. Nevertheless, the quantity of electricity supplied to customers cannot be permitted to take precedence over its quality. This is because the high penetration of the renewable-based power generation comes at the cost of power quality deterioration, especially at the point of common coupling (PCC), owing to nonlinear characteristics of renewable-based distributed generation (DG) systems and pre-contamination of modern distribution grids. So, the role of power quality (PQ) improvement technologies inevitably comes into the picture when the required level of renewable energy penetration is constrained by any of the grid PQ performance indices. Passive power filters (PPFs) have proven to be a very successful solution for increasing the harmonic-constrained penetration level (HC-PL) of renewable energy in power systems. However, there is a scarcity of information on how to choose between various passive filters to meet high penetration objective. The purpose of this paper is to look into the problem of filter type selection. The designing of different PPF types is formulated as an optimization problem with an objective to enhance the penetration of a renewable DG system in a distorted distribution power grid and solved by the firefly algorithm (FA). A comprehensive assessment of common PPF types, in terms of effectiveness in increasing renewable energy penetration in a harmonically polluted distribution grid along with their economic aspects, is performed. The simulation results show that the filters under consideration can be ranked from best to worst as composite type, third-order damped, C-type, second-order damped and single-tuned (ST) ones in terms of their performance on the percentage penetration level enhancement of renewable energy. While in terms of per-unit cost, the highest percentage enhancement in penetration is obtained by the ST filter. [ABSTRACT FROM AUTHOR]