基于磁光隔离器的电流测量系统的实验研究

发布时间：2018-01-09 19:20

本文关键词：基于磁光隔离器的电流测量系统的实验研究　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：电流互感器是电力系统中的关键设备,是连接一、二次侧设备的重要桥梁和纽带,因此电流互感器的可靠性、稳定性以及其测量精度与智能电网安全稳定运行的关系显得更加密切。随着智能电网数字化、网络化、信息化的深度不断加深和IEC61850标准的推广与使用,传统互感器的局限性也日趋显著,于是绝缘简单、动态范围大、频率响应宽的光学电流互感器(OTC)受到了学者们的广泛关注。尤其是在智能电网和特高压建设的大背景下,光学电流互感器的研究和使用将会对整个电力系统带来崭新的变革,但光学电流互感器的各方面研究已经进行了三十多年,到目前为止仍没有一种成熟化的产品应用于市场,究其原因,其工作性能还存在无法克服的缺陷。例如温度、双折射、热应力等对互感器测量精度的干扰。除此之外,价格成本、安装困难也是限制光学电流互感器大范围使用的主要原因。因此,探寻工艺更加成熟、用材更为常见、制作成本更加低廉的光学电流互感器显的尤为必要。本论文以光学电流互感器的研究为着眼点,先后阐明了传统电流互感器的缺点及使用的局限性和光学电流互感器的优点及存在的问题,并指出了光学电流互感器作为未来研究方向的客观原因与主观需求。基于此,本论文在详细介绍光学电流互感器原理、种类的基础上,进一步介绍了磁光隔离器等相关器件,提出了在光学电流互感器价格昂贵、安装困难、测量精度低、速度慢的情况下,能否在其他领域探寻新的器件和解决办法以大幅度降低制造成本与安装工艺的研究思路。本文根据新提出的研究思路,在充分比较各类磁光器件的基础上,最终选择了磁光隔离器为主要的研究器件和方向。结合磁光隔离器的结构和特性,搭建了以磁光隔离器为传感元件的光学测量回路,并对激光驱动及发射单元、光电转换及接收单元、AD采样及传输单元等进行了应用化设计。为满足电力系统对实时性的要求,最终选择了运算速度更快、内部资源更加丰富的FPGA作为主处理器,然后详细介绍了 FPGA的基本结构、芯片性能、硬件描述语言及开发流程,接着根据FPGA的设计化要求,搭建了基于FPGA的软硬件平台,对FPGA进行了接口设计、板卡外围电源设计、总线设计、AD采样模块设计、DMA数据储存模块设计和以太网设计等。在本文最后,搭建了整个光学电流测量系统的实验平台对偏振相关型磁光隔离器和偏振无关型磁光隔离器进行了磁场测量的实验研究,绘制了磁场与电压的关系点状图,并使用lsqcurvefit函数对磁场与电压关系进行了非线性拟合。经实验证明两款磁光隔离器具备了在磁场测量和电流测量领域应用的条件和特性,为下一步对温度、应力等特性的研究和实际产品的制造打下了坚实的基础。
[Abstract]:Current transformer is the key equipment in the power system, it is an important bridge and tie connecting the primary and secondary equipment, so the reliability of the current transformer. The relationship between the stability and the measuring accuracy of the smart grid is more closely related to the safe and stable operation of the smart grid. With the digitization of the smart grid, the network becomes more and more important. With the deepening of information technology and the popularization and use of IEC61850 standard, the limitation of traditional transformer is becoming more and more obvious, so the insulation is simple and the dynamic range is large. OTC-based optical current transformers with wide frequency response have attracted wide attention, especially in the context of smart grid and UHV construction. The research and application of optical current transformers will bring new changes to the whole power system, but the research on various aspects of optical current transformers has been carried out for more than 30 years. Up to now, no mature product has been applied to the market. The reason is that the performance of the product can not be overcome, such as temperature, birefringence. In addition, the price cost and installation difficulties are the main reasons for limiting the wide use of optical current transformers. Therefore, it is more mature to explore the technology. It is more common to use materials, and it is necessary to make optical current transformers with lower cost. This paper focuses on the research of optical current transformers. The shortcomings and limitations of traditional current transformers and the advantages and problems of optical current transformers are expounded. The objective reason and subjective demand of optical current transformer as the future research direction are pointed out. Based on this, this paper introduces the principle and category of optical current transformer in detail. The related devices such as magneto-optic isolator are further introduced. It is proposed that the optical current transformer is expensive, difficult to install, low measurement accuracy and slow speed. Whether we can find new devices and solutions in other fields in order to greatly reduce the manufacturing cost and installation technology research ideas. According to the new research ideas, based on the full comparison of various magneto-optic devices. Finally, the magneto-optic isolator is chosen as the main research device and direction. Combined with the structure and characteristics of the magneto-optic isolator, the optical measurement circuit with magneto-optic isolator as the sensing element is built, and the laser drive and emitter unit are designed. The photoelectric conversion and receiving unit AD sampling and transmission unit are applied to design. In order to meet the real-time requirements of the power system, the calculation speed is chosen to be faster. FPGA, which has more abundant internal resources, is used as the main processor. Then the basic structure, chip performance, hardware description language and development process of FPGA are introduced in detail, and then according to the design requirements of FPGA. The hardware and software platform based on FPGA is built, the interface of FPGA is designed, the peripheral power supply of the board is designed, and the AD sampling module is designed. DMA data storage module design and Ethernet design. The experiment platform of the whole optical current measurement system is built to measure the magnetic field of polarization-dependent magneto-optic isolator and polarization-independent magneto-optical isolator. The relationship between magnetic field and voltage is drawn. The nonlinear fitting of the relationship between magnetic field and voltage is carried out by using lsqcurvefit function. It is proved that the two magneto-optic isolators have the conditions and characteristics to be applied in the field of magnetic field measurement and current measurement. It lays a solid foundation for the further study of temperature and stress characteristics and the manufacture of practical products.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM933.1

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