Fiber Optic Current Sensor

Introduction

By using Faraday Magneto-optic effect, an optical fiber coil can be used as a current sensing element. This type of sensor is compact, light weight, and high speed device. The sensitivity of the sensor is inherently high since the interaction length can be as long as desired. These sensors are free from EMI and ESI. The transit time of light in the sensor region is very small and therefore response time of the sensor is very small. The fiber is dielectric component which eliminates the need for isolation in many high voltage applications. These devices do not suffer from the effects of saturation and have therefore excellent accuracy even under transient conditions. Measurement of high pulsed current (Imax = 1M, F 25 KHz) with accuracy of 1% is possible.

Special Features:

Current upto 1000 Amps are measurable with an accuracy of 2%. Effect of the induced linear birefringence in fiber and environmental perturbations on the measure values of current have been eliminated by using appropriate opt-electrnoics opto-mechanical techniques. For high values of current, accuracy of measurement is more.

Prospective Users:

Power Industry

Keywords:

Faraday rotation; current sensor, fiber optics

Type of Technology:

Product

Glossary:

Faraday rotation; When linearly polarized light passes through a transparent material of length L' kept in the longitudinal magnetic field H', the rotation of plane of polarization of light delta is given by = V.pi.H.d1; Where V' is the verdict constant of material.

Contact:

Managing Director
Foundation for Innovation and Technology Transfer (FITT)
Indian Institute of Technology, Delhi
Hauz Khas, New Delhi-110016, INDIA
Tel : 91-011-26597167, 26857762, 26581013, 26597153
Fax : 91-011-26851169
E-mail : drkdpn@gmail.com