Our commissioning engineer carried out a site survey at the Boots factory in Nottingham to assess the condition of the existing Generator Control Panels, GCPs, for the three Gas Turbine Generators on site.  We detailed the components inside the panels and provided recommendations for repair, testing or upgrade.  The client acknowledged the excitation and protection systems were obsolete and a modern upgrade of the system was carried out.

The legacy C10/120 excitation systems were upgraded to a Basler DECS250 AVR and the Alstom MiDOS protection relays were replaced with the Siemens Siprotec 7UM62. The scope of work included recommissioning the retrofitted GCPs, static checks on the generators, a new interface wiring design, secondary injection tests of the new protection relays, and dynamic commissioning of the excitation and synchronising systems.

Our engineers also dealt with the connection agreement between the client and the network operator National Grid Electricity Distribution. The Boots site has two grid network incomers, of which only one incomer had an existing contract. Our engineers successfully arranged a new connection agreement between the site and National Grid.  We also attended site to test the updated G59 protection as part of the new agreement.

Finally, we were asked to determine an optimal Power Factor for the three generators, considering the fluctuating factory load and the cost-benefit of exporting and importing real and reactive power from the grid.  We installed power loggers in the GCPs to collect data.  We then analysed the data to deduce the site reactive power requirements and determine the most economical operating Power Factor for the three generators.