Circuit for protection against slow circuit breaker closure during synchronization of a generator and an associated electrical system

摘要

The protecting apparatus includes a circuit for automatically and continuously determining the difference voltage between the voltage at the input side of a connecting circuit breaker and the voltage at an output side thereof between an electric generator and an associated power system, following initiation of closure of the connecting circuit breaker. The difference voltage is representative of the voltage angle of the generator relative to the electrical system. The difference voltage is compared against a reference value, which is selected such that a voltage angle value greater than the reference value will result in damage to the generator and/or the electrical system. An output signal is developed which can then be used to trip circuit breakers serving the electrical system if the reference value is exceeded by the difference voltage.