| 摘要 |
<p>388,362. Protective cut-out arrangements. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London. -(Assignees of Fallou, J.) May 18, 1931, No. 14631. Convention date, May 16, 1930. Void [Published under Sect. 91 of the Acts]. Drawings to Specification. [Class 38 (v).] Polyphase electric transmission lines or a section thereof are protected by injecting into each of the conductors of the line or section one phase of balanced high-frequency oscillations and utilizing the out-of-balance current which originates in the polyphase oscillations (in the event of a fault developing on the line) to energize a protective relay adapted to open a circuit-breaker to disconnect the line from the supply. Tuned stopper circuits are provided to prevent the superposed frequency trespassing on adjoining lines or sections. A circuit with circuit-breakers at each end may have a polyphase oscillation-generator connected at each end thereof, the generators being adapted to operate at different frequencies, and the necessary stopper circuits being provided.</p> |
