TY - JOUR

T1 - Analysis of Onshore Synthetic Inertia and Primary Control Reserve Contributions of Alternating Current-Side Meshed Offshore Grids with Voltage-Source Converter and Diode Rectifier Unit High-Voltage Direct Current Connections

AU - Herrmann, Michael

AU - Alkemper, Merlin

AU - Hofmann, Lutz

N1 - This research was supported by the German Federal Ministry for Economic Affairs and Climate Action within the framework of the project “North Seas Offshore Network II: Economical Connection and International Integration of Offshore Wind Energy in the North Sea” (German title: North Seas Offshore Network II: Kosteneffiziente Anbindung und internationale Integration von Offshore Windenergie in der Nordsee, FKZ: 03EI4009). The publication of this article was funded by the Open Access Fund of Leibniz Universität Hannover.

PY - 2023/9/19

Y1 - 2023/9/19

N2 - The increasing use of renewable energy sources in place of conventional generation units is leading to a reduction in onshore inertia and to the development of offshore wind park grids connected by multiple high-voltage direct current (HVDC) connections to the onshore alternating current (AC) grid. For AC-side meshed offshore grids with voltage-source converter (VSC) and diode rectifier unit (DRU) HVDC connections towards onshore grids, this study focuses on the energetic feasibility of synthetic inertia (SI) and primary control reserve (PCR) contributions triggered locally at the onshore converters of both connection types. To this end, the obstacles preventing contributions for VSC HVDC connections and the mechanisms allowing contributions for DRU HVDC connections are identified first. Based on these findings, the article proposes an enhancement of the offshore HVDC converter controls that is continuously active and allows locally triggered onshore contributions at all onshore HVDC converters of both connection types without using communication and requiring only minimal system knowledge. Additional simulations confirm that, although the enhancement is continuously active, the operational performance of the offshore HVDC converter controls for normal offshore grid operation and its robustness against offshore AC-side faults are not affected.

AB - The increasing use of renewable energy sources in place of conventional generation units is leading to a reduction in onshore inertia and to the development of offshore wind park grids connected by multiple high-voltage direct current (HVDC) connections to the onshore alternating current (AC) grid. For AC-side meshed offshore grids with voltage-source converter (VSC) and diode rectifier unit (DRU) HVDC connections towards onshore grids, this study focuses on the energetic feasibility of synthetic inertia (SI) and primary control reserve (PCR) contributions triggered locally at the onshore converters of both connection types. To this end, the obstacles preventing contributions for VSC HVDC connections and the mechanisms allowing contributions for DRU HVDC connections are identified first. Based on these findings, the article proposes an enhancement of the offshore HVDC converter controls that is continuously active and allows locally triggered onshore contributions at all onshore HVDC converters of both connection types without using communication and requiring only minimal system knowledge. Additional simulations confirm that, although the enhancement is continuously active, the operational performance of the offshore HVDC converter controls for normal offshore grid operation and its robustness against offshore AC-side faults are not affected.

KW - diode rectifier unit

KW - HVDC

KW - HVDC converter control

KW - offshore control concept

KW - offshore grid

KW - primary control reserve

KW - synthetic inertia

KW - voltage-source converter

UR - http://www.scopus.com/inward/record.url?scp=85172725201&partnerID=8YFLogxK

U2 - 10.3390/en16186700

DO - 10.3390/en16186700

M3 - Article

VL - 16

JO - Energies

JF - Energies

SN - 1996-1073

IS - 18

M1 - 6700

ER -