Protection system for power receiving station

A protection apparatus for a spot network substation having a plurality of receiving lines connected between a network bus and a plurality of power sources, each receiving line being connected to a primary switching device, a network transformer and a protector circuit breaker, wherein a detector for detecting a phase of each receiving line voltage and a judging unit for judging the detected phase are provided on a primary side of each network transformer, phases of the plurality of receiving lines are compared, and if there is a lag, the receiving line with the changed phase is judged that the corresponding power source is in a power-stop state and the protector circuit breaker is tripped.

A protection apparatus for a spot network substation having a plurality of receiving lines connected between a network bus and a plurality of power sources, each receiving line being connected to a primary switching device, a network transformer and a protector circuit breaker, wherein detectors for detecting phases of receiving line voltages are provided on primary and secondary sides of each network transformer, a judging unit for judging the detected phase is provided, phases on the primary and secondary sides of each network transformer are compared, and if there is a phase lag on the primary side, it is judged that the corresponding power source is in a power-stop state and the protector circuit breaker is tripped.

A protection apparatus for a substation having a generator connected with a power line and a receiving line connected to a switching device, a transformer and a secondary circuit breaker, wherein a detector for detecting a phase of a receiving line voltage and a judging unit for judging the detected phase are provided on a primary side of the transformer, an already stored basic phase is compared with the detected phase of the receiving line voltage, and if there is a lag in the detected phase of the receiving line voltage, it is judged to be a power-stop of a power source and the secondary circuit breaker is tripped.

A protection apparatus for a substation having a generator connected with a power line and a plurality of receiving lines each connected to a switching device, a transformer and a secondary circuit breaker, wherein a detector for detecting a phase of each receiving line voltage and a judging unit for judging the detected phase are provided on a primary side of each transformer, phases of the plurality of receiving lines are compared, and if there is a lag, the receiving line with the changed phase is judged that a corresponding power source is in a power-stop state and the second circuit breaker is tripped.

A protection apparatus unit for a substation having a generator connected with a power line and a plurality of receiving lines each connected to a switching device, a transformer and a second circuit breaker, wherein detectors for detecting phases of receiving line voltages are provided on primary and secondary sides of each transformer, a judging unit for judging the detected phase is provided, phases on the primary and secondary sides of each transformer are compared, and if there is a phase lag on the primary side, it is judged that a corresponding power source is in a power-stop state and the secondary circuit breaker is tripped.