Imperial College London

Professor Tim Green, FREng

Faculty of EngineeringDepartment of Electrical and Electronic Engineering

Academic Leader for Sustainability, Professor



+44 (0)20 7594 Website CV




1107EElectrical EngineeringSouth Kensington Campus





Half of my time is dedicated to my role as Academic Lead for Sustainability and in that role work to make the university's own activities sustainable. There are many dimensions to this: carbon emissions from our energy use; carbon emissions from goods and services we buy, biodiversity, air-quality and many more. Find out more on our Sustainable Imperial website.

The other half of my time is spent as a professor of power engineering. My research focuses on the analysis and technology to develop a zero carbon electricity supply system that is dominated by variable renewable sources and other inverter-based resources (IBR) such as battery energy storage. Such a system raises many challenges over how regulation of frequency and voltage, detection and location of faults and damping of unstable modes are ensured without the traditional synchronous generators that provide services in these areas. With colleagues Balarko Chaudhuri and Yunjie Gu, I attempt to provide the analysis tools and control innovations that solve these problems. A particular focus is on data-led (as opposed to physics-led) models for assessing whole-system stability. The approach is motivated by the opaqueness of the models of the IBR control software available from vendors. Here the term stability covers small-signal stability, large-signal stability such as fault ride-through, voltage recovery and frequency stability. I also attempt to address the problems of protection relying in inverter-dominated networks.

I welcome applications for PhD study in these areas but note that funding to support students is limited to a small number of positions per year. From time to time I recruit post-doctoral research associates. These posts will be advertised on (so no unsolicited applications for such posts please). I do welcome applications join my team as a visiting student or post-doctoral fellow provided these are for substantial periods of time (generally 6 to 12 months) and are externally funded.

Previously, I contributed power electronics circuit and converter designs for HVDC that reduce losses while also providing control functions to assist integration into AC systems. In distribution networks, I pioneered the use of so-called soft open points. I am no longer running active projects in these areas and therefore I am not recruiting team members on these topics.

My work has been supported by EPSRC, Hitachi Energy, and National Grid ESO and I work in collaboration with ESIG and G-PST.

I teach an introductory module in power engineering to Electrical and Electronic Engineering students and parts of specialist Masters modules

I am a fellow of the Royal Academy of Engineering, the Institute of Electrical and Electronics Engineers, the Institution of Engineering and Technology and the Chinese Society for Electrical Engineering.

Selected Publications

Journal Articles

Gu Y, Green T, 2023, Power system stability with a high penetration of inverter based resources, Proceedings of the IEEE, Vol:111, ISSN:0018-9219, Pages:832-853

Li Y, Gu Y, Green T, 2022, Revisiting grid-forming and grid-following inverters: a duality theory, IEEE Transactions on Power Systems, Vol:37, ISSN:0885-8950, Pages:4541-4554

Zhu Y, Gu Y, Li Y, et al., 2021, Participation analysis in impedance models: the grey-box approach for power system stability, IEEE Transactions on Power Systems, Vol:37, ISSN:0885-8950, Pages:343-353

Gu Y, Bottrell N, Green TC, 2018, Reduced-order models for representing converters in power system studies, IEEE Transactions on Power Electronics, Vol:33, ISSN:0885-8993, Pages:3644-3654

Merlin MMC, Soto-Sanchez D, Judge PD, et al., 2017, The extended overlap alternate arm converter: a voltage source converter with DC fault ride-through capability and a compact design, Ieee Transactions on Power Electronics, Vol:33, ISSN:1941-0107, Pages:3898-3910

Barklund E, Pogaku N, Prodanovic M, et al., 2008, Energy Management in Autonomous Microgrid Using Stability-Constrained Droop Control of Inverters, IEEE Transactions on Power Electronics, Vol:23, ISSN:0885-8993, Pages:2346-2352


Merlin MMC, Green TC, Mitcheson PD, et al., 2010, A New Hybrid Multi-Level Voltage-Sourced Converter with DC Fault Blocking Capability, IET Conference on AC/DC Transmission

More Publications