| 摘要 |
The level of stability of a synchronous machine can be assessed, inter alia, from the magnitude of the rotor angle, load angle or partial-load angle. The disadvantage of the measurement methods which have already been disclosed is that the said angles can neither be unambiguously defined nor measured during power supply short-circuits. The generator (1) supplies the transformer (19) via the power circuit breaker (17), which transformer (19), for its part, is connected to the power supply via the power circuit breaker (18). The machine parameters, which are detected by the trigger circuit (6), and the power supply parameters, which are detected via the measurement transformer (3) and the trigger circuit (2) and with the aid of a downstream-connected averaging device (4), are entered into the comparator stage (5) for steady-state values. The DC voltage pulses which are produced by rectifying one half-cycle are counted in binary form. After a specific time interval, the measurement result is detected by the averaging device (4) and is supplied to the comparator stage (5). It is thus possible to decide during the period of the short-circuit itself whether the angle, which will be reset after the short-circuit has been remedied, is still within a value which is acceptable to the machine or whether this value has already been exceeded. <IMAGE>
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