Contents lists available at ScienceDirect Electrical Power and Energy Systems journal homepage: www.elsevier.com/locate/ijepes MVfaultedsectionlocationindistributionsystemsbasedonunsynchronized LV measurements Panagiotis Bountouris a , Hao Guo a , Dimitrios Tzelepis b , Ibrahim Abdulhadi a , Federico Cofele a , Campbell Booth b a PNDC - University of Strathclyde, Glasgow, UK b EEE Department - University of Strathclyde, Glasgow, UK ARTICLEINFO Keywords: MV faulted section location LV monitoring Distribution network Unsynchronized LV measurements Voltage sequence components ABSTRACT Amediumvoltage(MV)faultedsectionlocationtechniquedependingsolelyonunsynchronizedlowvoltage(LV) measurementsindistributionsystemsisintroducedinthispaper.Theproposedmethodidentifesthe faultedMV feeder segment when an unsymmetrical MV fault occurs. It exploits parameters including voltage magnitude, angle and sequence components captured via distributed non-synchronized monitoring devices connected at secondarysubstations.Inthisstudy,thecharacterizationofasystem’sLVprofleduringMV faults was achieved throughout both software simulations and physical testing. The latter was conducted in the 11 kV and LV dis- tribution network of the Power Networks Demonstration Centre (PNDC) of the University of Strathclyde. The tests were performed for both 11 kV radial and ring network confgurations. Modelling and simulations im- plemented using the DigSILENT PowerFactory package, complemented the hardware level testing and provided the opportunity for further examinations, such as the impact of MV laterals connection, distributed energy resources on both MV and LV side as well as the presence of unbalanced loads. Finally, the paper evaluates the efectiveness of the proposed faulted section location technique under various physical and simulated fault scenarios, loss of communications and noise interference. 1. Introduction Efective fault location is an important function in the toolkit of Distribution System Operators (DSOs) as rapid location, isolation and repair of faults can ensure optimal power supply availability. Over the years, academia and industry have developed a number of methods based on technologies such as Time Domain Refectometry (TDR), Impedance Measurements (IM), Fault Passage Indicators (FPI), Travelling Waves (TW) etc. to achieve the aforementioned goal [1]. The impedance measurements based methods are one of the most common assessed techniques. They rely on phasors of fundamental frequency and are able to localize the fault by analyzing current and voltage measurements. They can be categorized as one-ended [2–4] or multi-ended methods [5],6,7,8 dependingonthenumberofnodesthey implement for capturing measurements. An impedance based fault lo- cation technique is described in [4], using modal transformation of voltage and current values captured at one-end substation. Although the fault locator is not afected by unbalanced loading, network con- fguration modifcations or non-homogeneous network sections, it is only focused on radial distribution networks and does not take into account the presence of Distributed Generators (DGs). In [6], another impedance based method implements high frequency transients pro- duced by the fault to calculate the fault distance. The above operation dependsonphasorsratherthansequencecomponentsanalysistorefect the potential asymmetry in a distribution system. Similar to previous approach,thetechniqueproposedin [2] takesadvantageofvoltageand current measurements provided by protection and metering equipment for fault localization in a 24.9 kV distribution network, considering uncertainties related to load as well as DG connection and variation levels. One of the key limitations of utilizing such methods in dis- tribution networks is frequently the lack of information associated to overhead lines and underground cables impedance/length, therefore compromising the accuracy and applicability of the fault location techniques. Furthermore, the installation of voltage and current moni- torsatmultiplepoints(GridSupplyPointandDGs)oftheHVsideofthe networkwouldrequireasignifcantinvestmentespeciallyinthecaseof more DGs are connected to the distribution system. Extensive research has been pursued regarding the applicability of travelling waves (TW) for fault location in distribution level. TW-based technology relies on the study of propagation time related to fault ef- fects. In transmission networks one-end [9] and multi-end [10,11] techniqueshavebeendevelopedexploitingthewaverefectionsandthe timethewavetakestotraveltothemeasuringpoint.Itisinevitablethat costly and sophisticated equipment such as high speed data acquisition devices, sensors and GPS are required to measure the transient wave- form. https://doi.org/10.1016/j.ijepes.2020.105882 Received 23 May 2019; Received in revised form 20 November 2019; Accepted 23 January 2020 Electrical Power and Energy Systems 119 (2020) 105882 Available online 07 March 2020 0142-0615/ © 2020 Elsevier Ltd. All rights reserved. T