An approach to the impedance modelling of low-voltage cables in digital twins

The volatility of distributed production and the uncoordinated charging of electric vehicles cause major challenges in terms of supply reliability and local congestion problems in the distribution networks. In order to tackle these two aspects preventively, digital twin models are introduced to analyse the impacts of these stochastic distributed grid exchanges. Herein, line impedances are a key feature which determines the accuracy of the model. The chosen software environment to set up these digital twins, is based on Carson's equations which are typically used for overhead high voltage lines. Hence, in this contribution an adapted model of Carson's equations on low-voltage underground cables at 50 Hz is presented, with the aim to develop a digital twin for analysing the integration of nowadays loads and distributed sources on low voltage distribution systems. Finally, the model will be validated based on realistic grid and smart meter data provided by a distribution system operator.