Sub/Near Synchronous Instability in the GB Network

Completed

Renewable Energy Sources
Other Cross-Cutting Technologies or Research(Energy Models)
Other Power and Storage Technologies(Electric power conversion)
Other Power and Storage Technologies(Electricity transmission and distribution)

Applied Research and Development

ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering)

Systems Analysis related to energy R&D (Energy modelling)

Project Contact
National Grid Electricity Transmission

Network Innovation Allowance

Ofgem

01 January 2020

31 July 2021

ENA months

£225,000

Power

London

Network Innovation Allowance

Project Contact, National Grid Electricity Transmission

The project will conduct a literature review to investigate a suitable modelling approach and assessment methodology for subsynchronous/near synchronous oscillation analysis. The project will then develop a time domain network model in PSCAD for selected areas of the GB network which will be validated by RTDS (real time digital simulation) testing. If the suitable PMU measurements available in the selected areas of the GB network, the model will also be validated against the measurements. The analysis will then be carried out in the validated model to understand the controller-related subsynchronous or near synchronous instability risk on the selected regions in the GB network. Finally, the project will explore an innovative active measure to address the instability risk. The scope of the work includes the following:1) Investigate suitable modelling approach and assessment methodologyLiterature review on occurrence of subsynchronous/near synchronous oscillations worldwide in power electronic dominated power systems, particularly in the area of subsynchronous/near synchronous oscillations resulting from controller interactions.Evaluate range of modelling approach and analysis methodology used for oscillation/resonance characterisation and identification and provide recommendation.2)Network modelling of the GB networkDevelop a network model for the selected future GB network for analysis of the resonance risk.Validate the model on a reduced GB model in RTDS.3)Recommend screening methods and detailed analysis approaches applicable to GB networkPerform detailed screening of controller interactions in the selected GB network.Analyse instability risk from the evaluation of the net damping condition of system resonances.Development of a toolbox for screening and analysis of resonance risk in the GB network.4)Explore an active mitigation measure to manage the risk in sub/near synchronous instability. The objective of the proposed work is to develop an indepth understanding of the different forms of sub and near-synchronous oscillations and the associated instability risk in the future GB sytem. The work will provide recommendations on a suitable modelling approach and analysis methodology. Nevertheless, the work is also aimed at exploring an active mitigation measure which is capable of reducing multiple frequency oscillations to mitigate the instability risk in the transmission network.

The GB electricity network is setting a fast pace of transition towards a net-zero carbon energy network. The system inertia and fault level are expected to decline continuously over time. Furthermore, the level of power electronic converters integrated into the ET network from renewable energy (e.g., wind turbines and photovoltaics), HVDC (High-Voltage Direct Current) links, traction loads, battery storage and FACTS (Flexible Alternating Current Transmission System) devices is going to increase dramatically and this will pose new risks to the ET network in terms of instability in the sub-synchronous and near synchronous frequency range. This is associated with transmission network resonant modes with power electronic converters time delay and control dynamics. The aim of this project is to understand the phenomena and assess the risk of sub-synchronous and near synchronous instability resulting from controller interaction with the sytem in future low carbon energy scenarios and develop an innovative mitigation measure to address it.

02/11/22