基于SEP4020的嵌入式继电保护装置的硬件设计.doc

摘 要 电子和计算机技术的迅猛发展对微机继电保护设计产生了深远的影响。微机继电保护装置结构上不断优化，功能上不断增强，应用上更为灵活。微机继电保护和变电站自动化系统的推广，对新型微机继电保护装置的设计与研制提出了许多新的问题和更高的要求。本文在借鉴国内外微机继电保护发展的成功经验基础之上，紧跟与继电保护相关的高新技术，分析并实现了新型继电保护硬件方案。CPU核心模块、数据采集模块、开关量开入、开出模块、通信模块、人机接口模块和电源模块给出了具体的硬件实现方案，详细说明了各部分电路的工作原理和PCB实现原则。软件的实现上，微机继电保护装置是以Nucleus为嵌入式实时操作系统来开发的应用程序，给出了软件总体设计框架，介绍了Nucleus系统初始化方式、中断管理流程以及任务调度方式。论述了交流采样算法设计和故障处理设计流程。 基于继电保护装置高精度和高可靠性的要求，本文深入分析了保护装置工作环境常见的干扰源及其干扰途径。对保护装置进行了采样回路二阶低通滤波，增设看门狗电路，电气防偷跳、电源系统和PCB抗干扰等措施来提高系统精度和可靠性。最后通过实验对保护装置进行了设置，实验结果表明：保护装置运行稳定可靠，各项保护功能都能准确实现，装置的测量精度和保护精度均以达到了较高的水平。通过对测试和实验结果的分析，为进一步改进继电保护装置设计提供了参考依据。 关键词：微机保护；硬件平台；SEP4020；采样精度；抗干扰 ABSTRACT The rapid innovation in microprocessor and communication technology has drastically boosted the development in power system protection. The structure of microprocessor-based relay protection device has been continuously optimized, and been more stronger in foundation.The spread of microprocessor-based relay protection and substation automation system bring many new question and higher demand to new design of relay protection. microprocessor-based relay protection. This thesis analysised and realized a new type of relay protection programme. Firstly, the development status and trend of microprocessor-based relay protection device were introduced. Expatiated the general principle, sort and requirement to relay protection device of power system of relay protection, and then analysised and compared several typical hardware platform of current. Established a single-core hardware framework base SEP4020. Currency and modularization design has been adopted in the thesis, and used ARM microprocessor SEP4020 as the control chip, the microprocessor is small sized, low power consumption, low cost and high perpormanced.Designed the hardware and software of relay protection device based on the chip. Discussed the main aspects of microprocessor relay protection including CPU, data acquisition and communication module, gived their schematic and PCB design rules. The real