【作者】 刘彬；

【导师】 徐雁；

【作者基本信息】 华中科技大学 ， 电工理论与新技术， 2007， 硕士

【摘要】 电流、电压是电力系统的基本物理量。电子式电流、电压互感器作为一种新型的电流、电压测量装置具有体积小、重量轻、无铁磁饱和铁磁谐振、频带宽、易于与微机保护接口等特点,近年来得到长足发展。但是与电子式互感器相配套的新型计量与保护技术的缺乏,则在很大程度上制约了电子互感器的推广应用。电力计量直接的对象是电子互感器,IEC标准统一规定了电子互感器的两种输出方式:数字瞬时值序列和模拟电压信号。数字瞬时值序列便于信号的远传通讯,基于电子互感器数字输出信号构成的电力计量系统从原理上可消除信号传输中的误差,同时计量测试中因温度或长期漂移影响带来的附加误差亦不复存在。因此研究适应于电子式互感器的全数字化计量方法及系统必将大力推动电子式互感器的发展。本文首先介绍电子式互感器的发展现状,提出了全数字化计量方法及系统的意义。然后,文中全面介绍了电子式互感器结构,重点分析了数据采集部分电参量采样方法和合并单元的数字输出接口。接着,本文提出了全数字化计量系统的整体设计方案,并简要介绍了各部分实现的功能。对于数字接口部分,本文在分析IEC61850-9-1标准协议和网卡芯片工作原理的基础上,设计了数字接收接口的软硬件,并实现了基本功能。对于接收到的数据,本文重点分析比较了各种高精度的数字化计量算法,在综合考虑了算法的准确性、可靠性、计算量及响应速度后,提出高精度的准同步DFT算法。最后,本文对各种计量方法进行了仿真计算和误差分析,对高精度加权算法实现了实际计量实验,并达到了0.2级准确度要求。更多还原

【Abstract】 Current and voltage are elementary parameters in power system. As new measuring instruments, electronic current transformer (ECT) and electronic voltage transformer (EVT) have been rapidly developed recent years attributing to their remarkable advantages: smallness、lightness、no ferromagnetic saturation、board band width and compatibility with interfaces of microprocessor based protection. But, the lack of the metering and protecting technology deeply restricts the development of electronic transformer.The direct object of power metering is electronic transformer. From IEC standards, electronic transformer has two kinds of output: digital signals and analog signals. Power metering system which based on the digital output of electronic transformer can eliminate the error in transmission abstractly. At the same time the additive error which brought from temperature or extended excursion is disappeared. Therefore, the research of digital metering technique and system can accelerate the development of electronic transformer consequentially.This thesis introduces the development of electronic transformer and the significance of digital metering technique and system. After introducing the structure of the electronic transformer, the thesis analyses the details about data acquisition system and the digital output interface of merging unit. Then, the whole design of digital metering system and the function of each part are introduced. Based on the analysis of the standard IEC61850-9-1 and the working process of network card, the thesis gives the solution to the digital input interface. To the data, the thesis compared some kinds of digital metering arithmetic, presents the quasi-synchronization DFT arithmetic after considering the accuracy, security, calculational capacity and speed. Finally, each kinds of mentioned metering arithmetic is emulated and the error estimation is also made.更多还原