| 摘要 |
877,698. Protective cut-out arrangements. BROWN, BOVERI & CO. Ltd. Feb. 18, 1959 [March 27, 1958], No. 5591/59. Drawings to Specification. Class 38 (5). In a distance protective arrangement, the line voltage is compared with a first reference voltage to produce a difference voltage and either a second reference voltage or the difference voltage is used to derive a rectangular gating waveform whilst the difference voltage or the second reference voltage is converted to pulse form, the gating waveform and pulses being applied to gating means which passes the pulses to cause the tripping of a protective device in dependence on the phase relationship between the second reference and difference voltages. The first reference voltage may be obtained from the line current and a reference impedance equal to the impedance of the protected section and the second reference voltage may be derived from the line voltage. |
