Under TOTEM 3, the TOTEM model will be enhanced through three key tasks:

1. Protection Elements – Develop UK-standard protection models (e.g., overcurrent, differential, distance) for key equipment, with implementation at substations.
2. Model Equivalents – Create tools for static and dynamic network equivalents to simplify studies and improve simulation speed without losing accuracy.
3. Model Enhancement – Convert the full GB network from PowerFactory to PSCAD directly, update models to reflect latest developments, and provide a user manual for independent model updates.

The project is a collaboration between NESO and UK Transmission Operators to expand TOTEM’s capabilities and usability.

Benefits

• For the estimation of benefits in this project, a risk- benefit analysis was adopted as the most appropriate method instead of a standard CBA. The main benefits of this innovation focus around the reduction of risk probability of a range of disruptive events which differ in their level of severity.
• The benefit of this project is estimated based on the potential systematic risk reduction and working hours reduction expected from using this tool. Additionally, by using this tool could also reduce probability of advance asset replacement by minimising oscillation events.
• A risk benefit analysis conducted in estimating the benefits of this project which resulted in £1.5m in 2018 real prices. However, due to the risk associated with this project, we accounted for the consequences of using this tool and applied the probability of failure at 30%, which resulted in a more conservative benefit value of £1m.
• The project has a BCR of £16, which means for £1 project spending, it returns £16 (£1+£15) in lifetime cost benefits. Annualised ROI: 6.2%. This is on top of the potential benefits estimated for TOTEM inclusive project.

Summary of Benefits:

The outputs from TOTEM 3 innovation project will allow TO’s to effectively maintain an accurate model which will establish the correct reinforcements to maintain a safe and secure transmission network. This should prevent the need for costly future reinforcements similar to the example below.

• At the time of construction of the Hunterston – Kintyre subsea cables, a harmonic filter was not installed as the model at the time didn’t have all the information it has now. If today’s model was used then a harmonic filter would have been installed for a maximum of £5M as it would have been designed into the substation and the required land acquired. Instead, a harmonic filter is now being retrospectively installed at a cost of approximately £18.5M as the substation needs to be extended to accommodate the harmonic filter equipment.
• There is also a resource time reduction associated with the outcome of TOTEM 3: using the tool to create equivalent models will save approximately 2 hours each time an equivalent model is created. As a representative example, considering the creation of 8 equivalent models per month and also updating the TOTEM model using the tools manual developed during an output of TOTEM 3 will save approximately 1.5 hours each time. Per month: 8 models created (2 hours saved each time) and 4 TOTEM model updates (1.5 hours saved each time) = 22 hours saved, the equivalent to 3 working days saved for one engineer. The saving here is approximately £909 per month (based on 23/24 prices) or £10,908 per year.
• The probability of failure for TOTEM 2 deployment is expected to reduce by 10% (from 30% to 20%) due to the TOTEM 3 efficiencies planned to be introduced. This reduces the overall project risk to 21.2%.
• Finally, the potential benefits expected from mitigation of major, minor and localised events and their associated assumptions remains the same as in TOTEM 2.

The estimated benefit value of TOTEM 3, based on the above example, is £11.6M (discounted, 2018 real prices) for SSEN-T and similar savings expected by the other TO’s. Accounting for risk, the risk adjusted value is estimated then to £9.2M (discounted, 2018 real prices). This is an indicative figure based on the Hunterston – Kintyre example only.