Empowering offshore wind with ES-STATCOM for stability margin improvement and provision of grid-forming capabilities.

Offshore wind power plants (WPPs) play a pivotal role in achieving a CO2-neutral electricity sector. However, their grid connection presents significant challenges and costs. High-voltage alternating current (HVAC) offers a cost-effective solution, but it may necessitate the installation of a static synchronous compensator (STATCOM) at the onshore bus to ensure stability and compliance with connection requirements. Integrating energy storage into the STATCOM (ES-STATCOM) enables the provision of ancillary services, such as inertial response and frequency support, which require active power. This paper utilizes the generalized Nyquist criterion to demonstrate that operating the ES-STATCOM with grid-forming control enhances the stability margin of the grid-connected WPP when compared to operating it with grid-following control. Furthermore, it illustrates through network frequency perturbation (NFP) plots that the overall WPP, comprising grid-following wind turbines and a grid-forming ES-STATCOM, imparts grid-forming behavior at the grid-connection point. • Small-signal model of HVAC-offshore wind farms is derived. • Mathematical models are used to evaluate small-signal stability of wind farms. • Grid-forming control for ES-STATCOM enhances stability of HVAC-offshore wind farms. • NFP plots are utilized to evaluate grid-forming capability of offshore wind farms. • Grid-forming ES-STATCOM can offer grid-forming capability to overall wind farm. [ABSTRACT FROM AUTHOR]