Offshore Wind Farm using Grid Forming Control & Energy Storage System for Frequency Stability
Authors
Devaraj, Aravind ; Papadopoulos, Konstantinos
Term
4. term
Education
Publication year
2023
Submitted on
2023-06-02
Pages
95
Abstract
Power systems are changing as inverter-based resources (IBR) such as wind and solar replace synchronous generators (SG). This reduces overall inertia, so frequency changes faster and becomes harder to control. At the same time, many renewable energy sources (RES) cannot increase output on demand without keeping headroom, which lowers utilization and creates economic challenges. This thesis examines grid-forming (GFM) control—an inverter strategy that makes plants behave like voltage sources that help set grid frequency—to improve frequency stability and inertial response (IR). It also assesses how adding an energy storage system (ESS) as an energy buffer can enhance system response. The power system is modeled in DigSILENT PowerFactory, and root-mean-square (RMS) simulations are performed. The ESS is treated generically without assuming a specific technology. ESS sizing is calculated to supply IR based on the largest contingency and limits on the rate of change of frequency (RoCoF). The thesis discusses parameters that influence ESS sizing and evaluates their impact on frequency dynamics. While simulations clearly show that ESS improves frequency stability, the necessary trade-offs in sizing are also considered. Beyond IR, ESS sizing for primary frequency response (PFR) is obtained, and improvements in frequency metrics are observed. The thesis concludes that operating wind power plants (WPP) and ESS in GFM mode is beneficial, and the results can inform improved GFM control coordinated with ESS to support power system stability.
Elsystemer ændrer sig i takt med, at inverterbaserede ressourcer (IBR) som vind og sol erstatter synkrongeneratorer (SG). Det sænker den samlede inerti, så frekvensen ændrer sig hurtigere og bliver sværere at styre. Samtidig kan mange vedvarende energikilder (VE) ikke øge produktionen på kommando uden at holde en effektmargin, hvilket mindsker udnyttelsen og giver økonomiske udfordringer. Denne afhandling undersøger netformende styring (GFM), en inverterstrategi der får anlæg til at opføre sig som spændingskilder, der hjælper med at sætte netfrekvensen. Formålet er at forbedre frekvensstabilitet og inertial respons (IR), og at vurdere hvordan et energilagringssystem (ESS) som energibuffer kan styrke systemets respons. Elsystemet modelleres i DigSILENT PowerFactory, og der udføres RMS-simuleringer. ESS behandles generisk uden at antage en bestemt teknologi. Dimensioneringen af ESS beregnes for at levere IR med udgangspunkt i den største driftsforstyrrelse og grænser for frekvensændringshastighed (RoCoF). Afhandlingen diskuterer de parametre, der påvirker dimensioneringen, og vurderer deres betydning for frekvensdynamikken. Simulationerne viser, at ESS giver en klar fordel for frekvensstabilitet, men de nødvendige afvejninger ved dimensionering adresseres også. Ud over IR beregnes ESS-dimensionering til primær frekvensregulering (PFR), og forbedringer i frekvensnøgletal observeres. Afslutningsvis fremhæves fordelen ved at drive vindkraftanlæg (WPP) og ESS i GFM-tilstand. Resultaterne kan bruges til at udvikle bedre GFM-styring koordineret med ESS for at styrke elsystemets stabilitet.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords