| 摘要 |
<p>PURPOSE:To stably detect the voltage of a main circuit by grounding the shield of current transformer through an impedance and dividing the voltage of the main circuit of a switchgear with the aid of the electrostatic capacity by a gas gap between the main circuit conductor and shield and the impedance. CONSTITUTION:The current transformer 3 obtained by winding coils 22a-22c around a cylindrical shield 21 is inserted in the main circuit conductor 8. When the shield 21 of the current transformer 3 is grounded through the low impedance 23, the electrostatic capacity 26 by the coaxial cylindrical gas gap 25 and the impedance 23 are serially connected between the conductor 8 and the ground 24. At such a time, the voltage V1 of the main circuit is divided with the aid of the electrostatic capacity 26 and the low impedance 23 and the voltage V2 having fixed rate to the voltage V1 is fetched from the connection point of the impedance 23. Thus, the voltage of the main circuit is stably detected with small-sized and simple constitution without using a transformer for a gauge.</p> |
