| 摘要 |
<p>PURPOSE:To easily mount on an existing facility and to eliminate necessity of separately providing a sensor protecting device by providing an optical voltage sensor for detecting a voltage between the upper end of a voltage dividing capacitor made of a ZnO element provided by conducting a lower part and an intermediate electrode and the electrode in a small-sized porcelain insulator. CONSTITUTION:A ground voltage V of a voltage applying side electrode is divided by utilizing a voltage dividing ratio C0/(C0+C1) of atmospheric capacitance C0 formed between an intermediate electrode 8 and the ground surface to the capacitance C1 of a voltage dividing capacitor 11, converted to an optical signal by an optical voltage sensor 12 connected to both electrodes of the capacitor 11, and output to the ground side. Since a mounting space for a voltage divider, etc., is not required at a porcelain insulator side, it can be easily mounted at the existing porcelain insulator unit. Since the ZnO element is used as the capacitor 11, when an overvoltage generated by the surge of a line is received, a resistance value is momentarily reduced, and the voltage between the electrodes of the capacitor 11 is held at the varistor voltage of the ZnO element. Accordingly, even if an arrester for protecting the circuit is not separately provided, it can prevent the sensor 12 from breaking down.</p> |
