Optimal Passive Filter Planning in Distribution Networks with Nonlinear Loads and Photovoltaic Systems

In this paper, the impact of grid-connected photovoltaic (PV) systems on voltage total harmonicdistortion (THDV) in radial distribution systems is investigated. To well present the behavior of PVsystems, both amplitude and phase angle of the harmonic current sources are considered in thesimulations. Specifically, when the current harmonic phase angle is considered, the photovoltaic andload harmonic may cancel out each other, which results in lower THDV values. It is also observed formthe simulation results that by increasing the PV penetration and nonlinear load demand, THDV mayincrease even beyond the allowed range. Therefore, an optimal passive harmonic filter (PHF) planningis also proposed for THDV mitigation and its effectiveness and applicability is tested and verified underdifferent working conditions. Optimal planning is performed considering a cost objective function whichincludes PHF cost and benefit of energy loss reduction. According to simulation result, an appropriatepassive harmonic filtering could guarantee an acceptable THDV in radial distribution and reduce energy losses.