Chapter 3 A Methodology Proposal for Calculation of Hosting Capacity Including Different Power Quality Phenomena Tiago E. Castelo de Oliveira and Paulo F. Ribeiro 3.1 Background Harmonic Distortion One of the key questions in the summarization of background distortion is related with the type of sources that can be aggregated, which will either cause positive or negative impacts. Their effect will depend on the nature of these loads and sources. There is a considerable number of studies in the background distortion field. Mostly, the knowledge of harmonic background distortion is based on harmonic injection in the majority of the cases. In this section, an analytical analysis that has been conducted on background distortion will be put forward, aiming at clarifying concepts that will later be used to define the concept of hosting capacity. In general terms, harmonic distortion, of either current or voltage, consists in a way to describe the principle of background distortion. Background harmonic distortion (BD or BHD) can be defined as the aggregated level of harmonic distortion present in the supply voltage at a point of common coupling (PCC) excluding the connection of a new linear or nonlinear load or generator to the PCC. This distortion may vary throughout the day in shape and/or in magnitude as well as phase of individual components. Thus, it may consequently increase or reduce the resulting distortion after the connection of a new nonlinear load or generator at the PCC. T. E. Castelo de Oliveira (*) Electrical Energy Systems, Technological University of Eindhoven, Eindhoven, the Netherlands e-mail: t.e.castelo.de.oliveira@tue.nl P. F. Ribeiro Advanced Power Technologies and Innovations in Systems and Smart Grids Group, Federal University of Itajuba, Itajuba, MG, Brazil e-mail: pfribeiro@ieee.org © Springer Nature Switzerland AG 2020 A. F. Zobaa et al. (eds.), Hosting Capacity for Smart Power Grids, https://doi.org/10.1007/978-3-030-40029-3_3 35