A frequency-output fiber optic voltage sensor with temperature compensation for power systems

We present a frequency-output fiber optic voltage sensor for power systems with temperature compensated response. The sensor employs PZT-type ceramic tubes, which are interrogated by a length of single-mode fiber coiled onto the tubes and a Mach-Zehnder interferometer. The combination of piezoelectric tubes with properties exhibiting opposite behavior to temperature changes is successfully exploited to passively compensate the temperature sensitivity of the sensor. The prototype reported here exhibits a resolution of 13 mV(rms) and the deviations of the sensor's response due to temperature changes are within 1% over the temperature range between -30 and 70 degreesC. The device presented here, in conjunction with a capacitive divider, is suitable for high voltage sensing. (C) 2003 Elsevier Science B.V. All fights reserved.