| 摘要 |
The invention relates to a method and arrangement for showing the phase sequence of a three-phase system. A second signal, which in terms of frequency and phase position corresponds to a first signal appearing between a phase conductor and the zero conductor, or between two phase conductors, is generated and maintained, even after the first signal is no longer sensed. The phase difference between the generated signal and a signal existing between other poles of the system is compared with predetermined values. From the result of the comparison, the relative phase position, or the phase difference, of the phase conductors is indicated. The arrangement according to the invention comprises measuring devices 14; 15, a phase-sequence indicator 16, a signal converter 17 connected to the phase conductors via the measuring devices 14; 15, a switch 19, a pulse generator 20, the output signal of which can be adjusted in terms of frequency and phase position for residual agreement with the signal from the signal converter 17, even if the signal from the signal converter 17 is discontinued, and a processing and comparator unit 21. <IMAGE> |
