Modelling and Power Flow analysis of the Electrical Distribution System at Norðurál Aluminium Plant
Author: Hörður Hermannsson
Year: 2023
Supervisors: Guðmundur Kristjánsson, Ragnar Kristjánsson
Abstract:
Norðurál has operated an aluminium plant in Iceland since 1998, where aluminium slaps are produced. The power used for the aluminum production is supplied by a transmission system operated by the Transmission System Operator (TSO) and distributed to various loads with an Electrical Distribution System (EDS) operated by Norðurál. Norðurál is currently in the process of expanding their aluminium production, by introducing a new product line. The new product line requires the construction of a new casthouse and substations, increasing the load on the EDS. The EDS has been operated with minimal change since its establishment and is the system power flow and loading relatively unstudied. This paper describes a model building of the EDS using the power system analysis software PowerFactory, with the aim of analysing possible power flow problems with the added load of the expansion. Two models are built of the EDS, one of the original system and another that includes
the aluminium plant expansion. The analysis of the system model, shows that a single three winding transformer is operated at a high loading, supplying the entire 6 kV section of the system. The model of the new additions shows that the three winding transformer approaches full loading with the added load of the new additions. Underground cables are used to transmit power within the EDS and does the model account for the reduced current capacity of cables installed underground. Analysis of cable loading identifies cable in both models that are operated at high or overloading. Harmonic analysis of the loads in the new casthouse, shows that the harmonic distortion of the new loads alone do not exceed industry standard limits.