About this Technical Webinar:
Synopsis | Sub synchronous oscillations (SSO) represent a critical phenomenon in modern power systems, particularly as networks evolve with higher penetration of renewable generation and power electronics. These oscillations occur when parts of the system interact at frequencies below the fundamental, potentially leading to instability, equipment damage, and wider system risks. The mechanisms of SSO have been recognised for decades, most notably in systems with series compensated transmission lines, but the growing role of converter interfaced generation and HVDC links has renewed the need for systematic study and mitigation.
This presentation provides both a theoretical background and a practical exploration of how SSO is assessed within the UK electricity network. The first section introduces the physical mechanisms behind SSO, differentiating between torsional interactions, control interactions, and network induced oscillations. Building on this foundation, the discussion highlights how these phenomena manifest in contemporary grids dominated by offshore wind, interconnectors, and advanced converter technology.
The second part of the presentation focuses on National Electricity System Operator (NESO) requirements and guidance for SSO studies. Recent publications and study frameworks provide developers and consultants with clearer expectations on when and how SSO assessments must be undertaken. This includes an overview of relevant methodologies, modelling considerations, and study boundaries, with particular attention given to practical challenges such as model availability, computational effort, and interpretation of results.
By linking the underlying theory with NESO requirements, the presentation aims to bridge the gap between academic understanding and industry practice. Attendees will gain insights into the drivers of SSO risk, the regulatory context shaping study requirements, and practical considerations for carrying out compliant and effective analyses. The session will also highlight both the risks posed by SSO and the opportunities for innovation in analysis, mitigation, and system design.
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Presenter: Rui Alves
Rui is a Principal Power Systems Consultant at Blake Clough, where he leads the company’s innovation pipeline and delivers complex technical assignments. He brings nearly a decade of experience in renewable energy integration and wind turbine technologies, with expertise spanning EMT and RMS power system studies, grid code compliance, harmonic analysis, sub synchronous oscillation assessment, and Mid Term Tender studies. His recent work covers solar, wind, and battery energy storage projects at voltages from 11kV to 132kV, addressing load flow, short circuit, voltage stability, frequency response, and fault ride through requirements.
Before joining Blake Clough, Rui worked as a System Planning Engineer at a UK Distribution Network Operator and as a Research Assistant at the University of Strathclyde, where he focused on converter control and power system dynamics, contributing to Ofgem innovation projects. He holds a PhD from Strathclyde on grid forming converter control and began his career as a Control Engineer at a leading wind turbine manufacturer. Rui is also a Certified Associate in Project Management.
