I’m sure many readers would question why anyone would want to perform a relatively expensive insulation power factor test on an inexpensive transformer. Typically, if any testing is done, it will be ...

The first case study is about an on-site measurement on a 66kV to 132kV reference VT. The secondary winding has two taps for adapting the voltage ratio between 132kV/√3:110V/√3 and 66kV/√3:110V/√3.

If the reliability of the public electricity supply is to be maintained in the future, routine diagnostic testing of transformers by the power utilities is no longer optional – it’s a necessity, ...

Solid-state ac supplies replace motor-generator and tap-changing transformers to offer the same tests at the push of a button • Solid-state ac-power sources combine the variable-frequency and ...

Transformers are very reliable devices and can provide service for a long time if regularly maintained and serviced. They’re also the single most costly item in any substation. To protect against ...