【作者】 徐江海；

【导师】 刘飞； 朱绍良；

【作者基本信息】 江南大学 ， 控制工程， 2008， 硕士

【摘要】 本文在分析国内外剩余电流保护器产品性能现状基础上,设计了以P87LPC767单片机为控制芯片的智能剩余电流保护器,具有显示、数据存储、查询、档位手动设置与自动浮动、动作相别指示等功能,充分利用P87LPC767单片机的资源,提出了系统的整体方案和实施的方法。本文重点阐述了剩余电流有效值和相位的测量方法。分析比较了数字采样技术的三种方法即同步采样、非同步采样、准同步采样法,结合剩余电流保护器功能要求,选择其中的非同步采样法,对于非同步采样产生的误差采用软件插值修正,保证了测量的精度,降低了产品成本,提高了性价比。对信号的测量,充分利用P87LPC767单片机的外部中断、定时器等资源,采用“半周波”采样测量计算有效值,较好地解决了数据采样运算与保护器运行实时性的矛盾。文中对制作调试的要点:判据的实现、多延时程序设计、误差分析与控制、电磁兼容性设计进行了重点分析。提出了剩余电流保护动作的两类判据;提出了减小测量误差的软硬件措施;利用已有基准信号作为单片机中断的触发信号,实现多延时任务程序的设计,提供了一种在没有定时器情况下编写延时、定时任务程序的方法;利用采样过程对高频干扰进行监测,有效地解决了系统电磁兼容性问题。更多还原

【Abstract】 An intelligent Residual Current Operating Protective Relay is designed in this article based on the analysis of domestic and foreign Residual Current Operating Protective Relay present product performance, which is controlled by P87LPC767 monolithic integrated circuit. The instrument managing the resources of the P87LPC767 monolithic integrated circuit has lots of functions such as data display, storage, inquiry and manual setting steps, automatic fluctuation, action phase instruction and so on. The thesis systematically proposed the whole design and the implement method.The technique of measuring residual current phase and its root-mean-square is discussed in detail in the thesis. This paper also has analyzed the digital sampling technique and has introduced three main digital sampling methods, which are synchronous, non-synchronous and quasi-synchronous sampling method. According to the function requirements of the Residual Current Operating Protective Relay, I choose non-synchronous sampling method to reduce product costs and to enhance performance and price ratio; at same time I select software to control measuring accuracy by the means of adjusting the differences. To the signal measure, I make the best use of external interrupt resources, timer and so on provided by P87LPC767 monolithic integrated circuit, meanwhile sampling and measure half period wave and calculate root-mean-square. Thus the contradiction between data sampling operation and protector action has been solved well.The debugging is analyzed as the emphasis in the article, including the realization of criterion, and the design of multi-time-lapse program, and analysis on error and restrictor on it, and the design on electromagnetic compatibility and so on. All these problems are settled in the paper, which gives two criterions on residual current protection and designs of hardware and software to cut down the infection of error. In the software programming aspect, the datum signal the trigger pip is used for the monolithic integrated circuit interrupt, so that multi-time-lapse procedures can be designed to realize a new to write time-lapse and delay procedures without timer. The problem of electromagnetic compatibility is settled effectively by a program designed to monitor the interference signal in high frequency.更多还原