Patent ID: 8271213
Filing Date: 2012-09-18
Classification: G01R

Abstract:
1. A system for online monitoring partial discharge, which is connected in parallel with a busbar between a generator and an electric network, comprising: a near-end circuit on a generator side, which includes a near-end capacitive coupling sensor connected to the busbar and a near-end impedor connected in series with the near-end capacitive coupling sensor; a far-end circuit on an electric network side, which includes a far-end capacitive coupling sensor connected to the busbar and a far-end impedor connected in series with the far-end capacitive coupling sensor; and a detection device, which has a near-end input terminal connected to a connection point between the near-end capacitive coupling sensor and the near-end impedor through a near-end cable, a far-end input terminal connected to a connection point between the far-end capacitive coupling sensor and the far-end impedor through a far-end cable, and a processing unit, wherein a length L of the busbar between the two capacitive coupling sensors, a length L  in which V the processing unit selects one pulse from each of a near-end signal input from the near-end input terminal and a far-end signal input from the far-end input terminal as a first comparison pulse and a second comparison pulse, and discriminates a partial discharge signal according to a comparison between a preset time delay threshold Δt otherwise, the processing unit selects a pulse having the largest amplitude in the far-end signal as the second comparison pulse.