Research On The Reliability Of Optical Current Sensor

The development of our smart grid and high-voltage, need the superiorperformance of the new current sensor to match advanced grid system. As a newelectricity metering equipment, optical current sensor has many outstandingadvantages compared to the large-scale used current transformer, focus show in theanti-jamming performance, insulation, as well as transient measurements, itrepresents the direction of development of the next generation current sensor.Although the development of optical current sensor reaches the stage of the productmarket, but also not a lot of use or in the main substation installation and operation.One of the root cause may be as a new type of equipment, the lack of optical currentsensor run history, reliability can not be learned, for safe operation in grid a longtime, many of staff in the industry lack of trust and confidence.This article first discusses bulk glass optical current sensor output accuracy,The main factor affecting its output results in the linear birefringence of sensingmaterial, verdet constant, temperature as well as the parameters of the light vectorprovide by light source system,the first two factor affected by the wavelength.Upgraded OCS is able to compensate for the impact of temperature changes,therefore, analyze the output from the dispersion aspect. Through the establishedOCS mathematical model in papers, linear birefringence and verdet dispersion aswell as their wavelength accumulation effect will eventually be reflected in theoutput. wavelength fluctuations of the light source to affect the output,then calculatethe allowable change of the operating wavelength range，in order to maintain thestability of the measurement accuracy.Secondly, establish the reliability analysis system of optical current sensor,including the failure mechanism analysis, the criterion of choice, the experimentalprogram and the reliability data analysis of four parts. The system provides amethod for reliability analysis of different OCS. When applied to other types ofoptical sensors reliability analysis, in accordance with its specific modelcharacteristics, picking out a reasonable criterion and experimental program.Finally, in accordance with the established analysis system, applied to thereliability study of bulk glass optical current sensor. Identify the failure mechanism,choice and quantitative calculation of the failure criterion, and then experiment withthe high temperature accelerated test method so that it exposed the lifecharacteristics as soon as possible, statistical analyze the experimental data, derivethe estimated useful life, loss of efficiency as well as the confidence of conclusions.