120 MVA grid transformer approval: In our largest single product approval to date, PND Ltd have recently on behalf of our Client, approved the design of two 120 MVA 132/22kV grid transformers. Both transformers will be entering service in the spring of 2012. The photo below depicts one of the transformers undergoing factory acceptance testing.

Use of an existing CDG11 protection relay with a modern 2.5 MW transformer rectifier unit: Where new transformer rectifier units have previously been paired with existing HV and dc switchgear, it was common practice to change the existing HV protection relay where the curve type offered (Standard Inverse) was not of the type normally used in a new installation (i.e. RECT). PND Ltd have established a method where the Standard Inverse curve can temporarily be used safely and effectively with a new traction rectifier which in turn avoids the need to deploy time consuming protection relay changeovers and wiring modifications.

Substation HVAC cost saving: PND Ltd were instrumental in recently achieving significant substation HVAC cost savings for our Client by deploying a time based dynamic approach to the modelling of electrical plant. This approach resulted in a reduction of both the HVAC scope and estimated costs in the order of £2.1M.