Fuzzy Algorithm for Power Transformer Diagnostics

Table 2

Classification of faults by IEC method [11].

Fault type	Characteristic fault	𝑅1	𝑅2	𝑅3
1	Normal ageing (N)	0	0	0
2	Partial discharge (PD) of low energy density	0	1	0
3	PD of high energy density	1	1	0
4	Discharges of low energy (D1)	1-2	0	1-2
5	Discharge of high energy (D2)	1	0	2
6	Thermal fault of low temperature (TL) < 150°C	0	0	1
7	TL between 150°C and 300°C	0	2	0
8	TL between 300°C and 700°C	0	2	1
9	Thermal fault of high temperature (TH) > 700°C	0	2	2