公开(公告)号：EP2682765A1

公开(公告)日：2014-01-08

申请号：EP12175142.4

申请日：2012-07-05

Applicant: ABB Research Ltd.

Inventor： Müller, Georg ,  Frank, Andreas ,  Bohnert, Klaus ,  Gu, Xun

IPC: G01R15/24 ,  G01R19/32

CPC classification number: G01R19/32 ,  G01R15/246 ,  G01R15/247

Abstract: In a fiber-optic current sensor, a 22.5° Faraday rotator, which is part of the sensing fiber coil, determines the working point of the sensor. The coil is operated with substantially linearly polarized light or incoherent substantially left and right circularly polarized light waves. In one arrangement, a polarization beam splitter generates two optical signals that vary in anti-phase with changing current. A signal processor determines the current from the two anti-phase signals. Appropriately detuned and oriented fiber-optic half-wave or quarter-wave retarders before the fiber coil are used to reduce or cancel the adverse effects of temperature and bend-induced birefringence on the measurement signal. Moreover, the temperature may be derived from the difference in the bias of the anti-phase signals and may be used to cancel temperature effects in the signal processor.

Abstract translation: 在光纤电流传感器中，作为传感光纤线圈一部分的22.5°法拉第转子决定了传感器的工作点。 线圈以基本线性偏振光或非相干的大致左右圆偏振光波操作。 在一种布置中，偏振分束器产生与改变电流反相变化的两个光信号。 信号处理器确定来自两个反相信号的电流。 在光纤线圈之前适当地失谐和定向的光纤半波或四分之一波长延迟器用于减少或消除温度和弯曲引起的双折射对测量信号的不利影响。 此外，温度可以从反相信号的偏置差导出，并且可以用于消除信号处理器中的温度效应。