Impact of Asynchronous Renewable Generation Infeed on Grid Frequency: Analysis Based on Synchrophasor Measurements

• Main Authors: Evangelia Xypolytou, Wolfgang Gawlik, Tanja Zseby, Joachim Fabini
• Format: Article
• Language: English
• Published: MDPI AG 2018-05-01
• Series: Sustainability
• Subjects: non-synchronous; renewable energy sources; frequency; rate of change of frequency; phasor measurement unit; inertia
• Online Access: http://www.mdpi.com/2071-1050/10/5/1605

The increasing power in-feed of Non-Synchronous Renewable Energy Sources (NS-RES) in the grid has raised concerns about the frequency stability. The volatile RES power output and absence of inertia in many types of NS-RES affect the balance between power consumption and production. Therefore, the dynamics of the power grid frequency become more complex. Extreme grid frequency deviations and fast variations can lead to partitioning and load shedding in the case of under-frequency. In the case of over-frequency, it can lead to overloading, voltage collapse and blackouts. The Rate of Change of Frequency (RoCoF) reflects an aspect of the stability status of the grid and therefore its analysis with regard to Non-Synchronous Instant Penetration (NSIP) is of great importance. In this work, two months of high-resolution frequency synchrophasor measurements during 18 January 2018–18 March 2018 recorded in Austria were analyzed to investigate the impact of NS-RES on the frequency. The correlation of RoCoF with the NSIP in Austria and Germany and with the frequency deviation were examined. It was observed that with a maximum NSIP share up to 74 % of the total power generation in these two countries, there was no critical increase of RoCoF or abnormal frequency deviation in the power grid.