ABSTRACT
Every DPV-GT transformer that is manufactured undergoes some form of factory testing. For DPV-GTs, these tests are quite extensive and a certain percentage of test failures do occur. Typically around 5" of the transformers produced will fail at least one of these tests. Test requirements are spelled out in a number of industry standards and specifications. There is some overlap among industry standards with respect to testing. In recent years ANSI/IEEE Standard C57.12.90 has been generally adopted by the other standards for testing liquid-immersed distribution, power, and regulating transformers. These transformers have special requirements of type tests, especially related to partial discharge. These requirements are stringent. A four-channel PD device using acoustic sensors was used to detect PD for a dry-type 1000 KVA DPV-GT. The testing is done when the transformer is in the plant being tested for induced voltage test.
