Error Research On In-line Fiber Optic Current Sensor

As an important part in the power system, sensor can provide measurement,protection, line diagnosis and power monitoring for the power system normal operation.With the development of electric power system, the sensor is developing rapidly. In thispaper, it takes the development of optic current sensor as the background, and makesfurther researches on the principles of light path and characteristics in the system ofall-fiber optic current sensor.Firstly, this paper discusses the theory of two kinds of all-fiber optic current sensor,which based on the principle of Faraday magneto-optical effect, and made detailedanalysis for the light path structure based on this theory. Than presents its theoreticaldeducing process for its polarization system. Secondly, through the analysis of thevarious devices of the optical path, we derive the Jones matrix of the devices, and thenbuilt the all-fiber optic current sensor model with the Jones matrix. In addition, it makea detailed description about the method for detecting signal of all-fiber optic currentsensor, and also give a way to modulate phase based on the digital closed-loop. Finally,using the Jones matrix method do a detailed analysis about the reason of optical systemcaused the device error, and gives the way to solve the error. According to the twosources of error affect by the temperature, puts forward a new method that errorcompensation use the1/4wave plate`s initial phase. Using this method, the simulationresults meet the0.2S level standards.In this paper, analysis of the optical system of the transformer, the optical pathdevice error solutions, for the full optical fiber current sensor research has somesignificance.