Analysing the stability of an islanded hydro-electric power system

Abstract

Power system simulation is a large arena especially in connection with the large European power system. The challenges of large interconnected electrical power systems call for a sophisticated system modelling solution that can give comparable results. This lead to project “iTesla – Innovative Tools for Electrical System Security within Large Areas” (iTesla 2016) which was funded by the European Commission. One result of that project was the open-source modelling library called “iTesla Power System Library - iPSL” (Vanfretti et al. 2016) which then later was forked and called “Open Instance Power System Library - OpenIPSL” (ALSETLab 2018). Those libraries are based on the open-source modelling language “Modelica” (Modelica Association 2017).

This paper presents the results of a Master’s thesis where Modelica was used in combination of the “OpenIPSL” library to model a small local distribution grid that is islanded.

It describes how to build the power system model using Modelica of a grid that is located in the Westfjord area of Iceland. That area of Iceland is only connected to the national grid by one transmission line. The reliability of the power supply is poor due to harsh weather conditions during winter.

Two models of the transmission system of the Westfjords were build. One is a base model with three generating units and one is an extended model with four generating units. Two different load scenarios were simulated. The result of which could give indicators as to what actions would help to keep the islanded grid stable.