Study on the Scanning Ultra-High-Frequency PD Detecting Method

Due to strong anti-interference ability, ultra-high- frequency PD Detecting is widely applied. Currently, how to collect partial discharge signals is the main challenge in this research field. As a common approach, on-line monitoring system needs to collect at least fifty continued power frequency signal samples. Because the partial discharge signal that in each power frequency is ranged from several hundred MHZ to several GHZ, conventional A/D acquisition cards do not meet the requirements of the sampling rate and the storage depth. Moreover, the costs for the A/D acquisition cards with high- speed and large-capacity are extremely high. The on- line monitoring system of scanning ultra-high- frequency discussed in this paper does not need acquisition cards. Signals are digitised in-situ, distributed monitoring system can be realized with great expansibility. The system adopts embedded processor and large scale complex programmable logical devices, which enabled the extraction of the PD characteristic value by using scanning and comparing methods and realised the function of on- line real-time monitoring with minimised components and volume for easy installation.