Fig. 1. Basic structure of SiPM unit

Fig. 2. Design of SiPM array PD sensor

Fig. 3. GIS optical-electric joint testing platform for partial discharge

Fig. 4. Models of artificial insulation defect

Fig. 5. PRPD spectra with three defects

Fig. 6. Statistical operators of different discharge types (the pressure of SF₆ is 0.3 Mpa)

Fig. 7. SiPM sensor installation mode

Fig. 8. SiPM field verification test

Fig. 9. PRPD spectra of SiPM field test