TAP CHANGER CONDITION DIAGNOSING

摘要

The present invention discloses a method and apparatus (4) for condition diagnosing of a tap changer (1) immersed in a cooling fluid (3), controlling and regulating an inductive power device (5), such as a transformer or reactor. The diagnosing method basically compares and evaluates expected heat exchanges between the tap changer (1) and ambient air and the inductive power device (5), an expected amount of heat generated by the tap changer (1) during operation, together with an actual temperature of the fluid (3). From the actual temperature, expected heat exchanges and expected generated heat, the heat balance in the system may be obtained and is used for disgnosing the operation conditions of the tap changer (1). The results from the condition diagnosing may be used as indicators (70) that can alarm operators or may be sent as a data signal (78) to remote and/or portable display means (79), such as a computer.