A Model of Intelligent Fault Diagnosis of Power Equipment Based on CBR

Table 2

Classification of transformer condition.

Number	Condition	Class code	Reason
1	OK		Normal status of transformer.
2	Low energy discharge		An intermittent discharge failure, such as potential discharge caused by poor contact discharge between the laminations, core and ground, and core and screw mandrel.
3	High energy discharge		High energy discharge means internal flashover caused by insulation breakdown between the coils and the overvoltage, flashover caused by lead fracture, and arcing faults caused by tap arcing or capacitive screen breakdown.
4	Partial discharge		It often occurs in the gas cavity and suspension charged body; its characteristic gas is hydrogen and methane, even a small amount of acetylene in high discharge energy density.
5	Low temperature thermal		Solid insulation suffers long-time low temperature overheat caused by overload or other reasons.
6	High temperature thermal		Insulating oil decomposes since inside heat is caused by equipment failure, and the reasons include tap poor contact, weak weld between leads and connections tap, and core multipoint grounding and partial short circuit.