Temperature Compensation Method for an Optical Direct Current Sensor Using Two Wavelengths and Technical Current Ripple

摘要

This paper introduces an optical direct current sensor, that uses technical ripple current to determine the magnitude of direct current, under consideration of the influence of temperature. Therefor, the influence of temperature is compensated with help of a method, that uses two wavelengths in time multiplex and technical current ripple. A simulation model of the sensor is used to describe the main influences of temperature, where linear birefringence changes are identified as the most important reasons for errors in current measurements. Due to lower costs and easy installation, a magnetic field sensor is used to determine the magnitude of a direct current with technical ripple, witch is installed in a electric single phase configuration in a climatic chamber. The method is proven by presenting comparisons of the results of current amplitude measurements in a range of realistic ambient temperatures to a conventional clamp-on current probe, with significant reduced derivation.