Table 3 Comparison of flux-based methods for internal fault detection and localization in power transformers.
From: Condition monitoring and fault diagnosis of power transformer based on non-invasive measurement
Method | References | General features | Non‐invasive/ invasive | Sensorless/ Sensor | Online | Offline |
|---|---|---|---|---|---|---|
Leakage flux | Can deal with winding movement | Non | Sensor | ✓ | ✓ | |
Can detect the faulty phase | ||||||
Insulation process for the high voltage side in case of search coil | ||||||
The ability for detection the intermediate faulty winding | ||||||
Search coil must be attached | ||||||
Core flux | Very simple | Non | Sensor | ✓ | ✓ | |
More accurate | ||||||
Very high sensitivity (0.1%) | ||||||
Can detect the faulty phase | ||||||
Achieve the localization process | ||||||
Proper performance in all abnormal conditions | ||||||
Search coil must be attached | ||||||
Linkage flux | Complex equation is needed | Non | Sensorless | ✓ | __ | |
Can detect the faulty phase | ||||||
Very stable performance in abnormal condition | ||||||
Low sensitivity level (10%) | ||||||
Transformer action | Can detect 2.5% faulty discs | Non | Sensor | ✓ | __ | |
The ability to deal with winding movement | ||||||
Valid for high voltage side only | ||||||
Very stable performance in abnormal condition |
