| 摘要 |
<p>PROBLEM TO BE SOLVED: To correctly diagnose insulation degradation in a coil which an A.C. rotary machine such as an A.C. motor comprises in an operating state. SOLUTION: An online insulation diagnosing device for an A.C. rotary machine to diagnose the insulation of a coil by detecting partial discharge which occurs in a three-phase A.C. generator in operation is provided with detecting parts 10A-10C to detect currents of phases (r), (s), and (t) passing through the A.C. rotary machine, HPFs 12A-12C to attenuate fundamental-wave components from each detected current signal, an A/D converting part 14 to digitize a current signal passed through each HPF, a processing part 18 to shift one of any two current signals by 120 deg. and perform subtraction between both signals after matching phases, a processing part 20 to determine the polarity that indicates in which phase the result of subtraction is a partial discharge which occurs, and a display device 22 to display the result of determination by a combination of two phases.</p> |
