Abstract: A method for determining phase locking of critical arc light includes: step 1: monitoring and collecting light radiation intensity of an arc inside a switch cabinet in real time, and converting the collected light radiation intensity into an electrical signal; step 2: extracting a power-frequency fundamental wave of the electrical signal, comparing an amplitude of the power-frequency fundamental wave of the electrical signal with a first threshold, and generating a pre-warning signal based on a comparison result of the first threshold; step 3: comparing the amplitude of the power-frequency fundamental wave of the electrical signal with a second threshold voltage, and generating a control signal based on a comparison result of the second threshold voltage and a protection time threshold; and step 4: protecting the switch cabinet under the critical arc light environment based on the pre-warning signal and the control signal.

Abstract: A partial discharge (PD) detection apparatus for gas-insulated equipment includes a photon collector, an optical splitter, a first photoelectric conversion module, an ultraviolet fluorescent crystal, a second photoelectric conversion module, and a signal processing module, where the ultraviolet fluorescent crystal is configured to convert a second optical radiation signal into an optical radiation signal of an ultraviolet fluorescence band, and the signal processing module is configured to calculate first apparent intensity based on a first voltage signal output by the first photoelectric conversion module, calculate second apparent intensity based on a second voltage signal output by the second photoelectric conversion module, and determine discharge intensity of the optical radiation based on a ratio of the second apparent intensity to the first apparent intensity. Technical solutions of the present disclosure are not affected by an unknown distance between a discharge position and a detection point.