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.

OCC, with its experience of and expertise in software development in the engineering sector, were the preferred choice when National Grid decided to improve upon their existing software for calculating thermal stress on large power transformers, a system known as TRALC. The new system, known as TRALC2, would see improvements in the user interface (which now produces a graph with 'draggable' points) and the thermal ratings calculations.

TRALC2 calculates the performance of National Grid's highest voltage transformers as they convert electricity supplied at hundreds of kilovolts via the grid to lower voltages for local distribution. Non-steady-state modelling of the electrical and thermal conditions within the transformers is required as their load can vary on a minute-by-minute basis.

Monitoring the load and stress on these transformers at any given time is crucial to the service provided by National Grid. When thermal stress reaches a critical level in a transformer, an automatic cut-out device is activated. Although safety is guaranteed, quality of power distribution can be compromised unless National Grid can foresee and allow for changes in performance of its transformers.

TRALC2 enables them to do just this. With its componential breakdown of data, it provides National Grid with information about the thermal stress which their transformers are undergoing, and advises engineers as to when the cut-off point will be reached under a given set of circumstances, and at what temperature. This knowledge, which is received well in advance, allows National Grid to make alternative arrangements in the use of its transformers for distributing electricity.