Digital protective relay
AssigneeKabushiki Kaisha Toshiba
InventorsMasamichi Saga, Itsuo Shuto
Life of this patent
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Abstract
A digital protective relay comprises a protective relay arithmetic processing unit for judging, based on a relay judgement quantity obtained by converting a system electric quantity into a digital value, whether in an operating state or in a non-operating state, and a time synchronizing unit for inputting a time reference signal from outside and synchronizing an internal timer of the digital protective relay with an external reference time. The time synchronizing unit includes an A/D converting unit for A/D converting the time reference signal inputted from outside with a resolution of at least 2 bits, and a decoding unit for decoding a time code signal by making a judgement as to a magnitude of the time reference signal with respect to a digital value obtained by the A/D converting unit.
Claims4
A digital protective relay comprising:
- protective relay arithmetic processing means for judging, based on a relay judgment quantity obtained by converting a system electric quantity into a digital value, whether in an operating state or in a non-operating state;
- and
- time synchronizing means for inputting a time reference signal, including a time code containing time information, from outside and synchronizing an internal timer of said digital protective relay with an external reference time,
- said time synchronizing means including:
- A/D converting means for A/D converting the time reference signal inputted from outside with a resolution of at least 2 bits and
- decoding means for decoding a time code signal by making a judgment as to a magnitude of the time reference signal with respect to a digital value obtained by said A/D converting means.
Dependencies are inferred from the claim text.