A Stray Current Sensor Based on an All-Side Cylindrical Spiral Fiber

In this paper, a stray current sensor based on an all-side cylindrical spiral fiber is proposed. The configuration of stray current sensor is illustrated first. The Jones matrix of sensor head is derived based on the geometric rotation effect. The output representation of stray current sensor is also obtained. Moreover, the effect of the characteristic parameters of sensor head on the output error is evaluated. On these bases, the genetic algorithm is applied to optimize these characteristic parameters in the range of the temperature-induced linear birefringence from 0° to 1000°. The optimization results include the following: For the vertical side, the length of cylindrical rod and the number of curve spirals are 1024 mm and 35, respectively; for the horizontal side, these two parameters are 876 mm and 28, respectively. The temperature experiments are conducted to test the performance of the stray current sensor with reference to that without cylindrical spiral fiber, and the test results indicate that the measurement error of the proposed stray current sensor is not larger than 0.4%, which can be suited for the stray current measurement in an urban rail transit system.