CONCEPT AND PRINCIPLE OF PD-CPWA
2.1 BASIC CONCEPT
Figure 1 shows typical phase-resolved PD characteristics (φ-q characteristics) of (a) air and (b) SF6gas, respectively, for a
needle-plane electrode system. Such phase-resolved PD
characteristics allow us to discuss statistical PD characteristics
and have contributed to identify the type of defects in the
insulating media from the viewpoint of the pattern recognition
technique.