Off-line ground fault detection system and method

• Main Authors: TENG XIAO, PU JIANFENG, MA LIJUN, YANG GUOZHOU, CHEN GUOLI, HAN FEI, LI DONG, CHEN BO, SUN SHENGLAN
• Format: Patent
• Language: Chinese; English
• Published: 22.03.2017
• Subjects: GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ONOTHER TECHNOLOGY AREAS; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORKOPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FORIMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION,DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TESTING

The invention relates to an off-line ground fault detection system and method. Firstly, through two three-phase short-connected lines, a three-phase detected line is in a short connection. The signal output end of a signal source is connected to any three-phase short-connected line, and the grounding end of the signal source is grounded, wherein the connection line L of the three-phase short-connected line and a three-phase detected line short circuit point is perpendicular to the three-phase detected line. An S characteristic signal is outputted, the S characteristic signal In of any phase of detected line at two sides of the connection line L, and n=1, 2, 3, 4, 5 and 6. The several levels of amplification and filtering of In are carried out alternately, and a vector value Y sinusoidal signal is obtained through analog-to-digital conversion and the FFT computing. The actual S characteristic signal current value Isn characteristic current is obtained according to the Y sinusoidal signal. A detected line with