
Modelling high-voltage transformers
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ncreased reliability achieved by software modelling - Improved management through scenario planning
Transformers and the national power network
National Grid chose OCC to develop and support "TRALC2", a desktop application which calculates the performance of National Grid's high voltage transformers as they are subjected to heavy electrical loads.
Transformers often acts as bridges between the high-voltage national power network and local electricity distribution. As current passes through the transformer it heats up (this is called "thermal stress") and under most conditions it is this stress that limits how much power a transformer can take.
Software predicts thermal stress
Non-steady-state modelling of the thermal conditions within the transformers is required as their load can vary on a minute-by-minute basis.
If thermal stress reaches a critical level a transformer will automatically cut-out.This either interupts the power supply to some part of the circuit or increases the load on partner transformers.
TRALC2 provides National Grid with models of the thermal stress their high-voltage transformers are undergoing, and predicts when operating and safety limits will be reached under given sets of conditions. TRALC2 can be used live to predict the performance of circuits in the next hours or minutes or it can be used months in advance to simulate the effects of planned maintenance.
Long-lived success
OCC delivered the first version of TRALC2 in 2000 and it is still being used, extended and supported. TRALC2 is a Windows application accessing a shared database of transformer and load data and running on the corporate desktop environment. Lately the TRALC2 model was integrated into the national control room's Circuit Thermal Monitor
National Grid is the largest privately-owned, independent transmission company in the world, and one of the top 100 companies in the UK. It owns and operates the high voltage electricity transmission system, which carries power from generators to suppliers across England and Wales. It also owns and operates transmission links to Scotland and France and plays a vital role in enabling the wholesale trade of electricity on behalf of the electricity market.

