PhD Studentship: Voltage Stability (Power System Dynamic Behaviour) Project Proposal

The Wind & Marine Energy Systems & Structures (WAMSS) is an EPSRC-funded Centre for Doctoral Training (CDT), led by the University of Strathclyde, working collaboratively with Universities of Oxford and Edinburgh. The Centre aims to train the next generation of technical leaders, through EngD and PhD graduates, for the Offshore Renewable Energy (ORE) sector.

This studentship is for PhD/EngD studentships available at the University of Strathclyde in the area of Power system dynamic behaviour and is for the next intake of the WAMSS programme which commences in October 2023. 

Oceans Wind (OW) is sponsoring this post graduate studentship. OW is an international company dedicated to offshore wind energy and created as a 50-50 joint venture, owned by EDP Renewables and ENGIE. Based on our belief that offshore wind energy is an essential part of the global energy transition, we develop, finance, build and operate offshore wind farm projects all around the world.  The UK remains the largest market for OW, with the OW office in Edinburgh supporting operations, construction and development across the current UK portfolio of 5 projects with a total generation capacity of 6.6GW.  The company is growing rapidly to deliver and operate these projects, including multiple engineering roles.

Problem definition

European Commission has set an ambitious target of reaching 60GW of offshore wind energy by 2030. This is on top of any other types of renewable energy sources (either existing or expected), namely solar or onshore wind energy as well as the phase out of existing conventional power generation. It is also expected that by 2050, Europe will be producing electricity only through renewable sources.   

The combination of the increased penetration of inverter-based generation and the decommissioning of conventional generation will create challenges in the voltage and transient stability of the network, including potential oscillatory interactions. Evident example of this is the August 2019 event in the UK where stability problems of an offshore wind farm partially contributed to load disconnection through the activation of low frequency demand disconnection mechanisms. Further to this, TSOs are looking into a more coordinated approach for the connection of the offshore wind farms to their grid. Consequently, connecting offshore wind farms to the same node (either onshore or offshore) have significant technical challenges that need to be overcome.

Key questions for offshore wind farms are to address stability issues when connecting to the grid in the most optimally technical and economic way as well as provision of any ancillary services to the network. In this regard, some key technical aspects that need to be addressed are:

1. i) Transient stability for the offshore wind farms. Identify methodologies and modelling techniques to evaluate control instability and robustness for HVAC connected far offshore wind farms. This can include the effect of offshore wind farms to existing generator transient stability.
2. ii) Interaction between controllers within the offshore wind farm as well as with the external network and/or other units. This is a power system level stability problem, and it is important to understand potential adverse interactions among several units and network elements. Study methodologies and modelling techniques for connecting offshore wind farms to multi-terminal HVDC systems.

Project scope

Traditional methodologies and modelling frameworks (e.g., phasor domain simulations) may not be applicable to identify instability and evaluate control robustness when connecting several large offshore wind farms with long export systems (either AC or DC) to the network.

To avoid this, new methods and tools need to be investigated and potentially developed to ensure that there is no adverse impact on the stability of the system when connecting large offshore wind farms to the grid. In particular, the aim of the project is to evaluate the applicability of new methodologies and modelling techniques during different stages of the development of offshore wind farms to allow better understanding, early detection, and mitigation of control instability.

Furthermore, and going beyond control tuning, different equipment could be used to improve stability of the system, including but not limited to synchronous condensers, STATCOMs, batteries or otherwise. Part of the project includes the investigation of the different technologies that can be applied and how the overall design of the offshore wind farms can ensure that the system is stable.

This studentship is open to UK and international applicants with a first-class or upper second-class degree (or equivalent) in mathematics or any scientific or engineering discipline.

For further enquiries related to the Centre for Doctoral Training contact: Drew Smith, CDT Administrator, Tel: 0141 548 2880, Email: drew.smith@strath.ac.uk

For further enquiries related to this research topic contact:  j.carroll@strath.ac.uk