| 摘要 |
<p>A circuit breaker and control system therefor adapted for use in protecting polyphase electrical transmission systems. Saturating current transformers are used to monitor each phase of the polyphase system. The saturating current transformers provide power to the circuit breaker control system. Information concerning the status of the line current in each phase of the polyphase system is provided in one embodiment by separate line monitors which may be, for instance, air core transformers or Hall generators. In another embodiment of the invention, no separate monitors are required for supplying information to the control system concerning the state of the current level in any of the three phases, since the saturating current transformers are used not only to provide energy for empowering or energizing the control system but also for providing the information concerning the status or level of the current in the phases. This is accomplished by obtaining information concerning the first portion of a sinusoidally shaped wave which is then interpreted electrically to predict the value of the peak of that wave even though the transformer may saturate before the peak is reached. The circuit breaker control system is adapted to provide both instantaneous tripping and time delayed tripping.</p> |
