Enhanced frequency control for greater decentralisation and distributed operation of power systems : design to laboratory validation

Student thesis: Doctoral Thesis

Abstract

With the increasing penetration of renewable generation in power systems and the consequent fall in system inertia, frequency control using conventional mechanisms is proving to be a major challenge for network operators around the world. Alternative faster means to manage frequency of interconnected power systems are being actively sought. At the same time, the need to prioritise remedial frequency control measures electrically closer to the source of a disturbance, referred to herein as responsibilisation ,is being realised.A frequency management approach that is fast acting and responsibilising ,a necessity for future power systems, is fairly non-existent in literature and present day power systems.This thesis works towards development of frequency control solutions that are fast acting and responsibilising, that is to ensure fast prioritisation of local response to a disturbance (electrically as close as possible), thereby driving towards a new paradigm of increased decentralisation and distributed operation of the power system. As responsibilisation is conventionally incorporated in secondary frequency control, its speed of response is improved.This is followed by introduction of responsibilisation within primary frequency control. The two proposed controls are enabled by effective event detection techniques developed. The effcacy of the two approaches is demonstrated and compared to that of present day control, by means of real-time simulation and small-signal analysis conducted on a reduced model of the Great Britain power system.The two control approaches ensure the prioritisation of local response to a local disturbance, reducing the divergence from planned system conditions, thereby minimising the operational implications of any system disturbance. In addition, they support enhanced scalability in the future grid given the relative autonomy of the approaches. This development will lead to increased system resilience during imbalance events.Demonstrating the feasibility of the proposed approaches in real-time simulations serves as a proof of concept, thereby appraising the solutions to technology readiness level (TRL) 3. The thesis continues to appraise the develop frequency control approaches to TRL 5, requiring high fidelity integration within a laboratory environment and a demonstration of its efficacy in relevant environment.In the process of appraising the developed frequency control approaches to TRL 5, this thesis presents the practical challenges of integrating novel control solutions within a laboratory environment for their validation. Using the smart grid architecture model (SGAM), a methodology to alleviate the presented challenges and facilitate the integration of radical control solutions within laboratory environments for their rigorous validation is proposed.Furthermore, in this thesis, the controller and power hardware in the loop validation of the developed secondary frequency control is shown to extend the traditional bounds of existing validation techniques.
Date of Award1 Dec 2016
LanguageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsUniversity of Strathclyde
SupervisorGraeme Burt (Supervisor) & (Supervisor)

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