Advanced stability assessment methods for power grids dominated by renewable energy sources

Modelling and Analytics for a Sustainable Society (MASS) is a Leverhulme Doctoral Scholarships programme at the University of Nottingham that aims to tackle the ongoing global problems of food shortages, water scarcity and insufficient clean energy by using mathematics to help understand and optimise resource use through predictive modelling and statistical analysis.

One of the key actions to meet the targets of the 2020 climate and energy package [1] to reduce greenhouse emissions and improve the exploitation of renewable energy is the redefinition of the paradigm behind electrical power generation. The electrical system has been recently moving from a top-down structure with centralised production mainly based on coal and nuclear to a new concept of the Smart Grid, in which distributed generation, based on renewable sources such as photovoltaic (PV) and wind, is connected at different levels [2].

In this scenario, Power Electronics represents a key enabling technology, since power converters are essential to interface renewable sources with the AC grid. When looking at renewables from a system perspective, it is often assumed that power converters are functional building blocks with an established technology. In reality, a power converter is a complex entity, with several and often non-linear control algorithms. When several converters are connected to the same power network, complex interactions occur, that might lead to instability of the electrical system.

The aim of this project is to explore advanced mathematical modelling approaches that can be applied to predict instability and define actions to mitigate the risk of undesired behaviours of networks of power converters. Different techniques have been proposed in literature, but none of them with general validity. The ideal outcome of this project is the development of a generalised modelling and stability assessment framework. The method will be used to predict the impact on stability of a new renewable generator, as well as to assess the capability of a network to accommodate a new generator.

Theoretical findings will be validated in simulation and on laboratory-scale experiments representative of practical application scenarios.

[1] http://ec.europa.eu/clima/policies/strategies/2020_en
[2] S. Bifaretti, P. Zanchetta, A. J. Watson, L. Tarisciotti, and J.C. Clare, "Advanced Power Electronic Conversion and Control System for Universal and Flexible Power Management," IEEE Trans. On Smart Grid, vol. 2, no.2, pp. 231 - 243, 2011
For more information, please visit: www.nottingham.ac.uk/mathematics/prospective/research/leverhulme-doctoral-scholarships.aspx

The Leverhulme Doctoral Scholars, who will be based in the new £7m Mathematical Sciences Building, will be exposed to an outstanding and vibrant research environment in mathematics, resource science, engineering and social sciences, with excellent opportunities for international engagement. At the end of their PhD, the Scholars will be eligible to apply for an additional one-year post-doctoral prize, funded by The University of Nottingham, to help establish their independent research careers.

Summary: The scholarships are for four years and will cover PhD tuition fees for UK/EU students, plus a tax-free stipend of £14,296 per annum (2016/17 rate). While the scholarships may be held by students of all nationalities, the Leverhulme Trust has a particular interest in supporting UK or EU students. International students would be expected to cover the difference between international and UK/EU tuition fees (currently approximately £9,500 per annum).