ABSTRACT
The first part of this chapter reviews how imperfections caused by sensor manufacturing, imperfect sensor components, temperature dependences, and/or mechanical stresses can limit the overall accuracy of fiber-optic current sensors. Next, the chapter discusses various noise sources (thermal noise, shot noise, and source intensity noise) and how they influence the precision of the current signal and minimum detectable current in dependence of the detected optical power, detection bandwidth, and number of fiber loops. Finally, the chapter presents long-term reliability tests of essential sensor components such as the light source and phase modulator and discusses results from a long-term field test of a three-phase current sensor system integrated into 420 kV circuit breakers.
