Digital Twin of Distribution Power Transformer for Real-Time Monitoring of Medium Voltage From Low Voltage Measurements

Abstract

Real-time monitoring of distribution systems has become necessary, due to the deregulation of electricity markets and the wide deployment of distributed energy resources. To monitor voltage and current at sub-cycle detail, requires, typically, major investment undertaking and disruptions to the operation of the grid. In this work, measurements of the low voltage (LV) side of distribution transformers (T/F) are used to calculate in real time the waveforms of their medium voltage (MV) sides, based on a mathematical model of said T/F. This model is, essentially, the digital twin of the MV side of the T/F. The method calculates T/F MV waveforms of voltage and current, and active and reactive power as accurately as an instrument T/F, captures all harmonics content, is unaffected by asymmetrical loading and identifies most system faults on the MV side of the T/F. The digital twin method enables monitoring of distribution T/F that avoids MV instrumentation, does not suffer in accuracy and may be readily deployable. Field data from an actual MV-LV T/F, agree with simulation results showcasing the efficacy of the digital twin method.