Citation: Igiligi, A.; Vielhauer, A.; Ehrenwirth, M.; Hurm, C.; Summ, T.; Trinkl, C.; Navarro Gevers, D. Assessment of Conservation Voltage Reduction in Distribution Networks with Voltage Regulating Distribution Transformers. Energies 2023, 16, 3155. https://doi.org/10.3390/en16073155 Academic Editors: Christina N. Papadimitriou, Andrea Michiorri and Carsten Hoyer-Klick Received: 10 March 2023 Revised: 27 March 2023 Accepted: 29 March 2023 Published: 31 March 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article Assessment of Conservation Voltage Reduction in Distribution Networks with Voltage Regulating Distribution Transformers Anthony Igiligi 1 , Armin Vielhauer 2 , Mathias Ehrenwirth 1 , Christian Hurm 2 , Thorsten Summ 1 , Christoph Trinkl 1 and Daniel Navarro Gevers 1, * 1 Institute of new Energy Systems, Technische Hochschule Ingolstadt, 85049 Ingolstadt, Germany; anthony.igiligi@gmail.com (A.I.); mathias.ehrenwirth@thi.de (M.E.); thorsten.summ@thi.de (T.S.); christoph.trinkl@thi.de (C.T.) 2 Maschinenfabrik Reinhausen GmbH, 93059 Regensburg, Germany * Correspondence: daniel.navarrogevers@thi.de; Tel.: +49-841-9348-2761 Abstract: The application of voltage reduction in medium and low voltage grids to reduce peak power demand or energy consumption has been implemented since the 1980s using several approaches. Conservation Voltage Reduction (CVR), as one such approach, uses a voltage control device to reduce or increase the voltage setpoint on a busbar, thereby reducing or increasing the amount of active and reactive power supply in the network. Voltage regulation for CVR is always implemented according to established network planning standards in each country. Research in this field has proven that a CVR factor (CVR f ) of 0.7–1.5 for peak demand reduction can be achieved. This is an evaluation metric of CVR. The aim of this research is to determine and validate CVR f for peak demand reduction by comparing actual results obtained during regular tap changes with other randomly distributed periods outside tap change operations, using a set of measurement data. It is important to understand CVR deployment capability by evaluating CVR potentials from historical random tap operations before a robust network-wide deployment is introduced. This research provides such guidance. It also provides a novel approach to determining tap changes from voltage measurements using a time-based algorithm. A CVR f ranging from 0.95 to 1.61 was estimated using a measurement dataset from a test field. The result of the entire evaluation shows that the CVR f are smaller during peak PV production and greater during peak demand periods. Further evaluation using statistical hypotheses testing and a control chart was used to validate the evaluation. Keywords: conservation voltage reduction; peak power; tap change; voltage regulating distribution transformers 1. Introduction The increase in power demand due to the rise of electric mobility, heat pumps, dis- tributed generation, and overall economic development has stretched the current German electricity distribution network to its maximum capacity [1]. Network expansion is consid- ered to be an inherent challenge as a result of increasing electricity demand from current and future building construction in the distribution network [1]. Although the infrastruc- ture cost of expansion can be curbed by implementing new grid optimization technologies, a few challenges remain. These challenges include a limited regulatory framework for wide adoption of the new technologies, additional equipment upgrades to improve grid compatibility, and implementation of Supervisory Control and Data Acquisition (SCADA) or advanced measurement devices for proper monitoring and measurement [2,3]. Demand is met with an increasing generation (at the distribution level) from Renew- able Energy Sources (RES) such as photovoltaic (PV) or wind power. Integrating RES into the grid requires a proper evaluation of voltage stability and other factors that can nega- tively influence the power supply. Consequently, optimizing power supply by deploying Demand Response (DR) and Volt/Var Optimization (VVO) can save huge infrastructure Energies 2023, 16, 3155. https://doi.org/10.3390/en16073155 https://www.mdpi.com/journal/energies