Case study on commercial sized MW-level microgrid

Abstract

The paper will give an overview of the MW-level microgrid case in Marjamäki in which all the production units and battery energy storage are connected to grid through an inverter. The focus on the paper is on modelling and simulation of transient dynamics at the time of islanding while there are no rotating AC machines for frequency nor voltage references. The industrial-type microgrid operates on medium voltage level. Based on the results, it is evident that with the chosen control method the energy storage is capable of supplying the needed active and reactive power while adjusting only its output voltage magnitude and thus, makes islanding possible. With the adopted method in this paper, the master and all the slave units can operate independently just monitoring their output values so that the communication between the units are not needed. The simulations were carried out by using PSCAD transient simulation software package.