Comparative Study on The Effectiveness of Partial Discharge Detection of Distribution Cables under Damped Oscillatory Wave Voltage and Ultra-low Frequency Voltage

Partial discharge detection with oscillatory waves and ultra-low frequency voltage as excitation sources is the main method of status detection and diagnostic testing of distribution cables. The application of oscillatory partial discharge detection technology starts early, and the detection and evaluation standards are relatively complete. With the promotion of ultra-low frequency dielectric loss detection technology, the partial discharge detection technology under ultra-low frequency voltage has also begun to receive widespread attention. However, its feasibility and effectiveness are still being further explored, and there is an urgent need for guiding detection methods, standards and evaluation criteria for on-site detection. Aiming at this technical problem, this paper completed a series of partial discharge detection tests of typical distribution cable and accessory defects under oscillatory wave and ultra-low frequency sinusoidal excitation voltage, and clarified the excitation effects of different excitation voltages on different defects according to the comparison and analysis results of partial discharge verification and apparent partial discharge. In view of the current situation of the distribution cable inspection test, a differentiated partial discharge detection technology application program was proposed.