ElectraNet's 275kV Reactor Replacement Cost Model

ElectraNet's 275kV Reactor Replacement Cost Model

Reactors are key components in transmission systems, supplying lagging current to reduce voltage fluctuations during load changes.reactor 275kv They can be supplied by dedicated equipment on the transmission system, or by existing synchronous generators on the network (although this pool of support is decreasing as generators decommission).

A reactor has a core and a winding made up of copper wire, which can be found inside a substation and in the overhead lines.reactor 275kv It is cooled by circulating oil or water, which helps to remove heat generated during operation. Insulation materials, such as mica, paper and epoxy, are used to protect the core and windings from damage.

The vast majority of the 275kV reactors needing replacement are located at GSP substations.reactor 275kv This means they could be affected by works on other parts of the network, which may cause delays or cancellations to outages. We’re working closely with the ESO to mitigate this risk and are engaged at an early stage of intervention planning so that we can optimise works plans where possible.

ElectraNet has developed a cost model that aims to provide consistency across the whole portfolio, and includes costs for both replacement and repair.reactor 275kv This was informed by a number of factors, including an understanding of the underlying risks and assumptions. This is a key part of our business case, which will be discussed at Ofgem’s T1 stakeholder event on 11 November.

Reactors are grouped by their End of Life (EOL) score, which is based on a combination of data sources, including Dissolved Gas Analysis (DGA), periodic inspection or more intrusive diagnostic tests where an asset’s condition has worsened significantly.reactor 275kv The EOL scores are also grouped by RAG status, to give a high-level view of the overall condition of the portfolio.

The EOL score for a reactor indicates that if it were to fail, there would be an unacceptable impact on system reliability. We use this as a guide for how to prioritise interventions and to inform our decision-making. This enables more planning compared to the Replace on Failure approach, and it reduces the risk of SQSS non-compliance.