【作者】 张帅；

【导师】 李正明；

【作者基本信息】 江苏大学 ， 农业电气化与自动化， 2009， 硕士

【摘要】 随着国民经济的发展,电能质量问题逐渐受到电力企业和电力用户的共同关注。建立电能质量综合监测系统,对电能质量进行长期、连续的监测,全面掌握电能质量状况,从而为改善电能质量提供依据是十分必要的。GPRS在原有的GSM网络中引入分组交换能力,大大提高了传输速率。将GPRS应用于电能质量监测仪表对于实现实时监测有较高的性价比和适用性。针对电网的特殊性,本文在分析了电能质量监测技术发展趋势和技术特点的基础上提出了以单片机为控制芯片,以GPRS为通信方式的电能质量监测仪设计方案。监测仪以美国Silabs公司的高性能低功耗SOC单片机C8051F020为核心。通过对GPRS技术的研究并结合电能质量监测的实际需要,选择西门子公司的MC35i作为监测仪的GPRS通信模块,实现了与监测中心的GPRS通信。A/D采样电路应用ADS7864芯片对电压电流信号进行六路同步采样,并采用硬件锁相环技术实现对信号的频率跟踪和同步采样控制,保证在一个信号周期内能够均匀采样到N点从而解决采样不同步导致的频谱泄漏问题。整个系统的软件部分采用模块化设计,不但提高了系统的运行效率,而且增强了程序的可移植性、可读性和查找错误的方便性,使系统软件结构更具有条理性。论文设计的监测仪在实验中取得了很好的效果,实验结果表明仪表具有较高的测量精度,可以满足电能质量监测的精度要求,数据远程传输安全稳定,达到了电力设备实时监控的要求。更多还原

【Abstract】 With the development of the national economy,the problem of power quality is getting more and more attention of the power companies and users.It’s quite necessary to establish the power quality monitoring system,so that we can get full grasp of status of the power grid with which we can improve the power quality.GPRS introduced packet switching method to the original SM net, thus enhanced the transmission speed dramatically.Applying GPRS to the power monitoring devices is of high cost-effectiveness and good applicability for the real-time monitoring.Given the specialty of the power grid,first the development trends and technical characteristics of the power quality monitoring technique is studied,then the method of adopting the SCM as the control chip and GPRS as the communication in the design of the power quality monitoring devices is introduced in this paper.The monitoring devices adopt the high effective and low-power consuming SOC-C8051F020 of the Silabs Company as the core.After a through study of the GPRS technique and the actual needs of the power quality monitoring,the MC35i of the Simens Company is adopted as the GPRS communication module of the devices,which is connected to the GPRS of the monitoring center.In the A/D sampling circuit,the ADS7864 IC is applied to the 6 lines synchronous sampling of the voltage and current signals,and the hardware phase-locked loop technique is applied to controlling of the frequency tracking and synchronous sampling of the signals,so that in one cycle a signal can be sampled to N points evenly as to solve the problem of the spectrum leakage caused by non- synchronous sampling.The software of the whole system adopt module design,which not only improves the operating efficiency,but also enhances the portability and readability of the process.The devices designed in this paper achieved good results in the experiment;the experimental results show that the devices have high measurement accuracy,which meet the requirements of the power quality monitoring,and the long-distance data transmission-which meet the requirements of the real-time monitoring of the power devices-is secure and stable.更多还原