| 摘要 |
In this voltage transformer for compressed-gas insulated high-voltage systems, between a straight internal conductor (1), which is located in a gas space (4) and forms a high-voltage electrode, and a low-voltage electrode (3) surrounding the internal conductor in the gas space (4) a measuring electrode (5) is arranged at which an output voltage is tapped off and fed to a signal processing system (6). In order to reduce the dependence of the output voltage on tolerances and fluctuations of geometric parameters, a guard electrode (7) is arranged between the low-voltage electrode (3) and the measuring electrode (5) and a plate capacitor (11), which is located in insulating gas, is placed between the measuring electrode (5) and earth. Between the guard electrode (7) and earth a supplementary capacitor (13) is also placed which is dimensioned in such a way that the capacitive voltage dividers formed by the internal conductor (1), the measuring electrode (5) and earth, on the one hand, and the internal conductor (1) the guard electrode (7) and earth, on the other hand, have approximately the same transformation ratios. The guard electrode (7) is earthed via a compensating device (14) the impedance of which is dimensioned in such a way that the time constants for the discharges of the measuring electrode 5 and the guard electrode 7 are approximately equal. |
