The reliability of transmission and distribution equipment

For all in the business of transmission and distribution equipment, reliability is of paramount importance. Customers flick a switch and take it for granted that power is available. Supply companies provide services poised to correct any interruption originating from weather or equipment. Transmission companies apply fault criteria to their designs; one, sometimes two, major elements can be absent and still everyone receives their expected share of power. Generation companies provide back-up to any loss and strive to maintain services which are interruption-free. Equipment companies build in margins and redundancies to ensure that equipment works when it should and, even more importantly, that it does not make the power system in which it works unreliable. Here, the author argues that reliability has to be pursued throughout the specification, design, manufacturing, testing and commissioning phases of transmission and distribution equipment as well as operation.<>