【作者】 李遥遥；

【导师】 李岩松；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2011， 硕士

【摘要】 随着国家坚强智能电网建设的不断发展,法拉第磁光效应光学电流传感器以其测量准确化、传输光纤化和输出数字化等优点必将成为服务于智能电网的理想传感器；然而,在实际应用中,由于受到温漂等外界因素的影响,光学电流传感器不能长期稳定工作,使得其一直没有得到大范围使用。为了解决影响光学电流传感器稳定运行的温漂问题,本文首次提出了解决影响光学电流传感器测量精度的温漂问题的双闭环负反馈自校正方法。本文从理论上论证了温度变化对法拉第磁光效应光学传感的作用机理,并且通过大量的实验对作用机理进行了验证。在此基础上,设计了全新的光学电流传感器双闭环负反馈自校正系统。该系统包括内环和外环两个独立系统：对于内环系统,通过在光源的输出口增加一个分束器,将初始光强按一定比例进行分离,并将部分光强反馈回直流源的控制系统,从而形成内环,稳定初始光强。对于外环系统,在原有光学电流传感器的基本组成结构上,将光电转换后的电信号进行高精度微弱信号处理,再进行高精度交直流信号的分离,提取出受温度影响的直流信号作为外环闭环量,将直流信号与光源设定电源输出的基本光强信号进行比较,比较值输入到高稳定度可控直流光源中。由此形成光学电流传感器的双闭环负反馈自校正系统。同时,再利用DSP系统对信号进行实时分析和处理,实现了系统的动态负反馈调整,实验结果达到了预期,抵消了温度变化对光学电流传感器测量精度的影响,从而进一步提高了传感器的测量精度和运行稳定性。更多还原

【Abstract】 With the development of State Strong Smart Grid, optical current transducer based on Faraday magneto-optical effect will become an ideal transducer to service the grid. Because it has many advantages, such as high measurement accuracy, optical fiber transmission, digital output and so on. However, due to the impact of external factors such as temperature drift in practice, optical current transducer can not work in the long-term stable situation, making it having not been used in a large range. To solve the problem caused by temperature drift, the double closed-loop self-tuning method is proposed in this paper for the first time. It has theoretically demonstrated the mechanism how temperature change affect the optical current transducer based on Faraday magneto-optical effect. And the mechanism has also been verified by a large number of experiments. On this basis, a new type of optical current transducer system has been designed. That is the double closed-loop self-tuning system. This system includes two independent systems, the inner and outer loop system. For the inner loop system, a beam splitter is added to the optical source output port to separate the initial light intensity according to a certain percentage. And part of the initial light intensity is fed back to DC source control system to form the inner loop system, making the initial light intensity stable. For the outer loop system, in the original optical current transformer basic structure, the photoelectric conversion electric signals are processed by the high-precision weak signal processing method, and then separated by the high-precision AC and DC signals separation method. The DC signal affected by temperature change is extracted as outer loop component. After DC signal is compared with the basic light intensity that is set by optical source, the compared value is input into the high-stability optical source with controllable DC source and the DC source current is provided to the optical source of optical current transducer. Thus, the double closed-loop self-tuning system is formed. At the same time, DSP system is used to analyze and process signals realtimely. So it has realized dynamics negative feedback adjustment and the experimental results have reached expected targets. And the influence, caused by temperature change, is also offseted, which will further enhance the measurement accuracy and operational stability of optical current transducer.更多还原