【作者】 赵瑛毓；

【导师】 白焰；

【作者基本信息】 华北电力（北京）大学 ， 控制理论与控制工程， 2002， 硕士

【摘要】 现场总线控制系统（FCS）取代分散控制系统（DCS）已经成为自动化技术的发展趋势。相应的，采用数字传输技术的现场总线智能仪表正逐渐成为自控领域发展的热点。基于上述技术背景，课题设计开发了基于WorldFIP现场总线的一种底层设备－微机电量变送器。文章从应用角度出发对WorldFIP现场总线协议及其技术特点，通信处理器MicroFIP芯片的功能和结构以及相应的开发工具等内容进行了阐述，分析了其在电力行业的独特优势。合理选择采样算法是提高微机电量变送器准确度的重要环节。通过对各种采样算法的分析，采用具有完全滤掉各种整次谐波和纯直流分量功能的傅氏算法且采样率为12点/周的交流采样方案，它是能兼顾精度与速度的“最佳”组合。变送器硬件设计以M68HC12单片机为核心，采用硬件测频技术与高精度高速A/D，对电流、电压进行同步交流采样。软件上考虑了谐波、频率对测量精度的影响，使用自检方法以及抗干扰技术。该装置采用以MicroFIP芯片为核心的WorldFIP通信卡代替以往的RS-485，根本上改善了通信性能。通信卡能够完成WorldFIP协议所规定的物理层和数据链路层的所有功能。软件设计完成MicroFIP寄存器的初始化和读写、网络变量的配置和管理，实现WorldFIP通信功能。该装置具有较高的精度和理想的实时通信性能，为WorldFIP现场总线底层设备的后续开发奠定了基础。更多还原

【Abstract】 Having replaced DCS (Distributed Control System), FCS (Fieldbus Control System) has become the tendency of automation technology. Accordingly, the intelligent instrument adopting digital transmission technology is becoming the focus in the field of automation.According to the forementioned technical background, the paper will plane to study on the field instrument based on WorldFIP fieldbus in the bottom layer, microcomputer transducer of electric variables.The protocol and features of WorldFIP fieldbus, MicroFIP component and the device WorldFIP development kit are introduced from the point of application. On the basis of analyzing we have a conclusion of its unique advantages in the power system.To seek an appropriate algorithm is an important task for improving the accuracy of microcomputer transducer of electric variables. Through comparison of all sorts of sampling methods, the conclusion is obtained: under the sampling rate of 12 point/cycle the Fourier algorithm would meet the need of both accuracy and speed. The transducer adopts M68HC12 microcontroller as the core in hardware design; The frequency measurement unit employs hardware to measure frequency. The advanced techniques are applied in it, such as synchronous sampling, high speed and high precision A/D converter. The influence of harmonics and frequency on the accuracy of measurement is considered; Self-testing method and anti-interference measures are adopted in software design. Instead of RS-485 interface, a communication board of WorldFIP whose core is MicroFIP chip, can improve communicate capability. The board can accomplish the functions specified by the physical layer and data link layer of WorldFIP protocol. We can fulfill initializing of register and writing and reading of network variables and message. And then, the transducer of electrical variables can communications with other <WP=4>eqiupments based on WorldFIP fieldbus.In conclusion, the transducer has higher measuring precision and powerful real-time communicate function. The study will establish favorable base for latter development of field instrument based on WorldFIP fieldbus. Zhao yingyu(industrial automation) Directed by Professor Bai yan更多还原