【作者】 李炜；

【导师】 杨以涵；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2003， 硕士

【摘要】 传统电磁式CT具有较高稳态电流测量精度，但存在饱和问题；而光学电流互感器(简称OCT)无此缺点，能测量故障暂态电流，但受温度应力引起的线性双折射的影响大，精度较低。本文采用自适应技术和小波变换，提出了组合式光学电流互感器(HOCT)，使这两种互感器有机结合，达到优势互补。HOCT通过模型参考自适应技术和小波变换来实现对电流的测量，本文提出了两种可行的实现方案。在对四种自适应算法进行仿真实验比较之后，选出一种最优算法QN算法并加以该进，引入了块最小均方误差的概念，提出一种新的BQN算法，通过光学实验室物理实验验证其有效性。对两种方案各提出一种小波变换：基于Mallat算法的小波变换和递推复小波变换，通过EMTP仿真实验和数学模型仿真实验分别对这两种小波变换的故障时刻检测效果进行验证。实验结果表明：这种基于自适应技术的组合式光学电流互感器从根本上解决了一般光学电流互感器最困难的问题：线性双折射的影响，大大提高测量精度，而且摆脱了材料、工艺等的制约，提高长期运行的稳定性，因而加速了OCT的实用化进程，在OCT市场上具有更强的竞争力和更广阔的发展空间。更多还原

【Abstract】 Conventional electromagnetic current transformers(CT) possess high accuracy of steady-state electrical current measurement, but produce problems caused by magnetic saturation. By comparison, optical current transducers(OCT)have many advantages over CT and can measure fault transient current. However, temperature or stress-induced linear birefringence in sensing materials cause error and instability. Based on adaptive signal processing and wavelet transform, hybrid optical current transducers are put forward in this paper, which can bring advantages of CT and OCT into play.Two schemes are advanced in this paper to measure transient current. After many tests on four model reference adaptive signal processing algorithms, improved upon the optimal QN algorithm , BQN algorithm is put forward which introduces the concept of block mean square error(BMSE). In optical lab this algorithm is tested to be satisfying.Two wavelet transform algorithms are advanced for the two schemes respectively: Mallat wavelet transform algorithm and realtime recursive wavelet transform algorithm. It is proved that the algorithms proposed are accurate to detect singularity of fault transient signals in power system by a mass of tests such as EMTP simulation and math model simulation.HOCT based on adaptive theory eliminates linear birefringence and overcomes restraints of optical materials and technics. So current measurement accuracy and stability of long-term running can be improved greatly. HOCT possesses stronger competitive power than other types of OCT.更多还原