| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a transformer for amplifying type instrument of high reliability without damaging a voltage measurement function even at the worst failure. SOLUTION: A first input side zero-phase voltage detecting part 5 is provided to the input side of a first voltage amplifying part 4 which amplifies voltage obtained by electrostatic voltage-dividing action between a three-phase main circuit conductor 1 and a ground, and a first output side zero-phase voltage detecting part is provided to the output side thereof, and a first zero-phase voltage monitoring part 7 which takes in, compares and monitors zero-phase voltage detected with both the detecting parts is provided, and a first output switching part 8 which opens/closes output voltage of the first voltage amplifying part 4 is provided. In the same manner, a second voltage amplifying part 14, a second input side zero-phase voltage detecting part 15, a second output side zero-phase voltage detecting part 16, a second zero-phase voltage monitoring part 17 and a second output switching part 18 are provided. Further, a switching control part 20 which takes in a result of monitor of the first and second zero- phase voltage monitoring parts 7 and 17 and controls the first and second output switching parts 8 and 18 is provided.</p> |
