Kabushiki Kaisha Toshiba

Masato Okazaki

Masao Hori

Hirosi Nisida

Noriyosi Suga

Kuniyasu Imamura

A bus-bar protection relay equipment includes a data-acquisition means, a check zone protection means, a fault bus-bar judging means, and a tripping bus-bar judging means. A data-acquisition means transforms analog current signal from the current transformer connected to the bus-bar with two or more dependency regions into digital data at every predetermined cycle. The check zone protection means computes amount Id (vector sum) of operation, and the amount Ir (scalar sum) of inhibition using the digital data transformed by this data-acquisition means. The check zone protection means transforms analog current from the current transformer of a line segment into digital data &ldquo;n&rdquo; multiplied with. The amount Id of operation and the amount Ir of inhibition are computed. An actuating signal is outputted when predetermined relationship is satisfied by using the amounts Id and Ir. The fault of the internal and the external to the area which included the computed value two or more dependency regions by a predetermined a percentage differential protection calculation is judged. A fault bus-bar judging means,performs a fault bus-bar judging by two or more above-mentioned dependency regions using the operating quantity which computed the operating quantity and computed it in the operating quantity and the check zone protection means which were computed.

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Tokyo, Japan

Masato Okazaki