Experimental study of slit selection for an arc channel schlieren observation system

When the external insulation of a power transmission system is subjected to severe lightning and operating surges, the leader discharge would form an arc channel resulting in the system failure. Thermal parameters are the key parameters in the study of arc channels, and can be obtained through schlieren measurement. In this paper, an arc channels' schlieren observation platform is built, a calibration curve for the arc channels' schlieren observation system is established by this platform; the optimal slit for arc discharge schlieren observation is selected through the calibration curve established before, and the arc channels' schlieren observation test is verified by calculation. The results show that the biggest square slit is the best for arc channels' schlieren observation and the smallest diameter slit is the worst. This paper provided guidance for the selection of slits for subsequent schlieren measurements.