| 摘要 |
FIELD: measurement technology; monitoring extensive three-phase cable lines for condition. SUBSTANCE: device designed for monitoring insulated- or compensated- neutral cable lines of large power substations to detect phase-to-ground fault in cable functions to analyze level of harmonic components of zero-sequence current for each connection in digital form and also to analyze data on current flow direction in connections. Selective device has zero- sequence current transformers, matching stages, multiplexer, analog-to-digital converter, band filter, phase-sensitive unit, random-access memory units, autoregressive filter, averaging adder, faulty- phase channel detecting unit, maximum choice unit, current relay, threshold elements, switching circuit, display unit, and control unit. EFFECT: enhanced efficiency. 2 cl, 10 dwg |
