【作者】 韩绍甫；

【导师】 杜树新；

【作者基本信息】 浙江大学 ， 模式识别与智能系统， 2006， 硕士

【摘要】 电能质量监测作为电能质量监控的一个关键环节,在系统运行管理和技术监督中起着重要作用,同时也是保证系统良好供电质量的必要条件。功能强大的电能质量监测系统的建立,能详细记录系统运行过程中的电能质量指标、监督电能质量污染源,并进一步为电网电能质量的治理和改善提供依据。电能质量主要包括稳态电能质量和动态电能质量。本文提出了在小波分析的基础上开发电能质量综合监测系统的思想,不仅能监测常规的稳态电能质量问题,还能实现对电压骤降、骤升、间断等动态电能质量的监测。 本课题从以下方面对电能质量监测进行了研究。 1.利用小波分析能检测突变点的性质,本文应用小波变换方法实现了电压骤升、电压骤降、电压间断等动态电能质量的监测,仿真表明,小波分解后的高频系数重构图形可清楚地确定电压发生突变的位置,得到电压突变的起止时刻。 2.应用小波包方法实现稳态电能质量的监测,从而较好地跟踪谐波的变化趋势,同时对高频信号进一步分解,具有较好的高频分辨率,仿真表明,可以利用小波包变换可以较为准确地提取出电网信号中的所有正弦信号的时频特性,达到对谐波分析的目的。 3.结合GPRS通讯技术与J2EE技术搭建了电能质量监测系统,从而实现电能质量参数的远程、实时监测和分析。该系统具有远程监控、客户端免维护、服务器端易维护、系统安全可靠、操作简单方便等优点,并通过国家电网公司验收,在上海市区电力局正式投入使用。更多还原

【Abstract】 Power quality monitoring is a key part for the control of power quality. It is also a necessary condition to ensure good power supply. The establishing of power quality monitoring system can not only get the targets of power quality during the running of the system in detail and supervise polluted object, but also provide evidence for improving and renovating the power quality. Static power quality and dynamic power quality are also concerned today. The idea to develop a comprehensive monitoring system of power quality based on wavelet is brought forward. It monitors not only static power quality but also dynamic power such as voltage sag, swell and momentary interrupt.The problem of power quality has been researched from three aspects in this paper.1. With the capability of wavelet to detect disturbed points, wavelet is used to analyze the dynamic power quality. In this paper the signals of swell, sage, momentary interrupt are simulated with the methods of wavelet, and the simulations show the method of wavelet can fix on the positions of the voltage break.2. In addition, wavelet packet method is used to analyze static power quality. In this paper the voltage signal with harmonies is simulated with the methods of wavelet packet. And as a result, the wavelet packet method has a good performance in high-frequency. It’s proved that all of the harmonies signal can be picked up by using the wavelet packet method. And it has a good performance on analyzing the harmonies signal.3. With the technology of GPRS and J2EE, the monitoring system of power quality is developed. It’s used to monitor and analyze the power quality data in real time and in long distance. Compared with other systems, the developed system has the advantage of long-distance monitoring, easy maintenance and easy operation etc. This system has been accepted by state grid. And it has been running in shanghai power.更多还原