Power electronic interfaced generation (PEIG) has become significantly dominant in the electrical power grid. This development is leading to a decrease in systemic inertia and damping against electrical oscillations. This causes the introduction of new and faster dynamic phenomena. One of these phenomena is sub-synchronous control interaction (SSCI), occurring as sub-synchronous oscillations (SSOs) in the system. Several real-world events reported so far have been related with large wind power plants (WPPs) and the improper tuning of the grid side converter (GSC) of (type-4) fully rated converter (FR C) wind turbines. As other PEl G have similar topologies and control systems, it is a very relevant topic. Weak grid conditions often contribute to the risks of SSO events. This paper proposes supplementary wide-area damping (WAD) to the control system of the GSC, focused on damping excursions of the phase locked loop (PLL). Signals measured by a remote phasor measurement unit (PMU) are communicated to the control system, which uses it for dynamic damping control. The effects of the WAD are tested by comparing the results of linearization-based eigenvalue analysis with and without the addition of WAD. Supplementary analysis conducted by using time-domain simulations and Prony analysis confirm the positive effect of WAD. Numerical tests are performed in DlgSILENT PowerFactory 2023 SP2 on a modified IEEE-39 bus test system.

The Spanish Central System is an intraplate mountain range dividing the Iberian Inner Plateau in two sectors – the Duero Basin (N) and, the Tajo Basin (S). The latter has an average altitude of 450-500 m while the former presents a higher average altitude 750-800 m. This intraplate orogen features a thick-skin pop-up and pop-down configuration formed by the reactivation of Variscan structures. Its high topography is the response of a tectonically thickened crust evidenced by 1) the geometry of the Moho discontinuity 2) an imbricated crustal architecture and/or 3) the rheological properties of the lithosphere. Research has been carried out to build a lithospheric-scale model across the orogen. A 400 km long multi-seismic transect has been acquired using natural and controlled source seismic data. The earthquakes and seismic noise data was acquired over a period of one to two months of continuous recording along a linear array (69 short-period seismic stations). The controlled source data included over 1000 stations and a series of acoustic sources. This effort has delineated the geometry of the base of the crust by: Global-Phase Seismic and, conventional noise interferometry, and, wide-angle imaging. The Global Phase approach used PK, PKiKP and PKIKP phases of earthquakes (> 120° epicentral distance). Stacking of the autocorrelations of these phases contribute to a pseudo zero-offset X-section. The application of ambient noise seismic interferometry complements the zero-offset reflection image, defining the geometry of the Moho. Further details on the lithospheric structure is provided by seismic wide-angle reflection images, which reveal a clear thickening of the crust below the Central System resulting, most probably, from an imbrication of the lower crust. Accordingly, the crust-mantle boundary is mapped as a relative flat interface at approximately 10 s two-way travel time except under the Central System, where this feature deepens towards the NW reaching more than 12 s. An intra-crustal boundary is well defined at 5 s. Reflectivity within upper-mantle depths is scattered throughout the profile, located between 13-18 s, and probably related with the Hales discontinuity. Funding resources: EU EIT-RawMaterials Ref: 17024_20170331_92304; MINECO: CGL2016-81964-REDE CGL2014-56548-P: JCYL: SA065P17)