How Grid Forming Technology is changing
What is Grid Forming technology?
Grid Forming technology is a control technique that enables inverter-based resources (e.g. wind, batteries, solar photovoltaic systems etc) to act as a voltage source behind an impedance, or in simpler words to mimic the behaviour of the traditional synchronous machine.
Why do we need Grid Forming technology?
Grid Forming capability unlocks various desirable dynamic responses from inverter-based resources that could help stabilising the grid – for example fault infeed and inertia. Grid Forming capability has become an optional part of our Grid Code following Ofgem’s approval of the Grid Code Modification GC0137 in early 2022.
What has changed and why?
Grid Code modification GC0163 will provide flexibility to developers by allowing them to utilise a real, virtual or combination of real and virtual impedance between the Internal Voltage Source of the Grid Forming Converter and the Grid Connection Point. The modification has progressed through an industry consultation and is now approaching the final stages of the Grid Code Governance process. Subject to Ofgem approval, the change could be part of the grid code by Q3/Q4 2024.
This grid code modification was suggested by an industrial Expert Group which developed the Great Britain Grid Forming Best Practice Guide following collaboration with industry, academia and manufacturers. The guide provides further understanding and details of the requirements to implement Grid Forming capability as detailed in the Grid Code. As part of this work, it also provided a list of suggested enhancements to the Grid Code Grid Forming requirements.
Grid Forming Best Practice Guide
What’s next?
We will soon launch another round of proposals to modify the Grid Code in line with the suggested changes arising from the Great Britain Grid Forming Best Practice Guide in addition to the wider industrial experience gained from the Stability Pathfinder work.
We aim at prioritising the modification proposals in accordance with the priority order set out in the Best Practice guide. In preparation to this, we aim to present our thinking to industry over the next few months, and as part of this work we will include within the terms of reference whether future plants should be mandated to have a Grid Forming capability.