| 摘要 |
<p>PURPOSE:To remove the effects of potentials impressed on the object other than the conductor being measured and measure the voltage accurately without contact by surrounding the conductor and the electrode with a shielding pipe and thereby operating phase separation. CONSTITUTION:In the case of operating non-contact potential measurement by electrostatic induction with an 8-phase batch type SF6 gas-insulated electric machine, the voltage division ratio of the electrostatic capacity between electrode 5 and conductor 2 and known impedance 12 are measured in advance. The voltage at this voltge-dividing point is amplified by high-input-impedance amplifier 13, and thereby the voltage of conductor 2 is displayed on meter 14. At this time, to avoid the influence of V-phase and W-phase, electrode 5 and conductor 2 are surrounded by shielding pipe 8 sufficiently longer than the gap between electrode 5 and conductor 2. When each voltage of the 8 phases is measured, shield pipe surrounding is performed for each phase. By this, it is possible to operate non-contact voltage measurement accurately.</p> |
