The Massive Glass Optical Current Transformer Optimization

The optical current transformer as a new kind of measuring tool which has the advantagesof convenient installation, easy operation, high precision measurement appears in recent years.The most perfect all-fiber optical current transformer has been officially put into use andachieved good results. In this paper we study a new type of current transformer--the bulk glassoptical current transformer. Compared with all-fiber optical current transformer, the bulk glassoptical current transformer has its own advantages: simple structure, convenient assembly, highprecision of measurement.In this paper we analyze the works of he bulk glass current transformer, and focuses on thecore of bulk glass optical current transformer--magnetic optical glass. We analyze the linearbirefringence and Verdet constants from two respects of theory and experiment. At the same timewe design the optical fiber collimator, forecast and solve the possible problems in the assemblingprocess. The contents of the paper include:The first chapter introduces the main advantages and the reasons of rapid development of theoptical current transformer, we compare different types of OCT to point out the developmentdirection, and design a new sensing head--the bulk glass sensing head.The second chapter is about the theory and gives the Jones matrix of the light, polarizers,wave plate and the magneto optical glass through establishing mathematical model. We get theexpressions of measured current in conditions which consider linear birefringence and neglectslinear birefringence by using Jones vector method.The third chapter is the experiment part of the paper. Firstly we theoretically analyze the twomain parameters, linear birefringence and Verdet constants, how to influence the accuracy ofmeasurement. On this base, we give different ways to reduce effects which caused by linearbirefringence. Secondly we design experimental method and use this method to measure linearbirefringence. From the results and the theory we get the conclusion that only when linearbirefringence is small, the influence on the measurement result can be ignored. At last wemeasure Verdert constants by using different light sources and know that the product of Verdetconstants and the square of the wavelength is approximately equal to the constant, and this canconform with theory well.The fourth chapter introduces the design of the optical fiber collimators, experimentalcomponents of the system performance impact on measurement accuracy and sensor head’sassembly program. We analyze the loss of the fiber collimator coupled mismatch in theory andput forward the design principle of fiber-optic collimators. According to the design principle,specifications and experimental requirements given in, we design fiber collimator which is meeting the requirements; we choose each component which constitute the experiment systemrespectively and analyze the polarizer’s degree of polarization, polarizer’s extinction ratio, thedefault angle of the polarizer Etc’s impact on the measurement accuracy. We give in the methodof assembling sensor head and predict the problems that may arise in the assembly process. Wealso propose a set of effective programs to improve the measurement accuracy of theexperimental system.The fifth chapter is the summary of the paper.The third chapter and the fourth chapter are the core of this article, and the work I did ismainly on this. This paper is the combination of experiment and theory, and it really has a certainreference value on the utility of the bulk glass optical current transformer.