| 摘要 |
<p>PROBLEM TO BE SOLVED: To restrict measurement errors caused by vibrations, changes of surrounding temperatures, etc., and improve measurement accuracy in a photocurrent sensor which is used to measure a current of an extrahigh voltage system with the use of advantages such as insulation and noise resistive properties, etc. SOLUTION: A magnetic field detection part 23 for detecting a current flowing in a conductor 22 from a magnetic field generated by the conductor 22 is constituted of a Rogowskii coil 30 and a converter 31 electro-optically converting detection results of the Rogowskii coil 30. The magnetic field detection part 23 transmits and receives the light from a light transmission detection part 24 via transmission part 25 comprising optical fibers 35, 36. A turn of a polarization plane of the optical fiber 35, 36 does not influence measurement results. Therefore, even when a swirl occurs in the polarization plane because of vibrations or a change of surrounding temperatures, the influence of the turn can be neglected.</p> |
