基于DSP的电容电流测量关键技术研究  

Research on Key Technology of Measuring Capacitance Current Based on DSP

作　　者：李付亮 周有庆[2] 王晓芳[3] 

机构地区：[1]湖南省水利水电职业技术学院,长沙410131 [2]湖南大学电气与信息工程学院,长沙410082 [3]邵阳学院电气工程系,湖南邵阳422000

出　　处：《电测与仪表》2009年第11期16-19,23,共5页Electrical Measurement & Instrumentation

摘　　要：近年来,随着配电网结构的不断变化,注入信号法测量电容电流得到了广泛的应用和重视。而在实际应用注入信号法测量电容电流的过程中有两个瓶颈问题还没有得到解决,即注入信号的信号源和滤除50Hz信号的问题,这就限制了注入信号法在电容电流测量中的应用。分析了注入信号法测量电容电流原理,采用自适应相干模板法滤除信号中的50Hz工频信号,并运用了先进的32位数字信号处理器TMS320F2812来进行信号处理。通过检测注入电流信号和返回电压信号的相位差来确定电网的谐振频率并计算配电网对地电容电流值,来实现电容电流精确测量。实验证明,该方法在电容电流的测量中具有准确、方便、安全的特点。In present years, with rapid change of power distribution network structure, the signal injection method to detect capacitive current has been widely used and focused. But, in the practical application, this method has two bottlenecks which have not been solved. One bottleneck is how to design a signal source which provides injecting signals; the other is how to filter 50Hz signals out. These two difficulties limited the signal injection method in application. To cope with the ditScuhies, this paper proposed a method of adopting adaptive template to filter out the 50Hz signal; besides, an advanced 32-bit digital signal processor TMS320F2812 was discussed, which had been used in the device. By detecting the phase difference between the current injected signal and voltage signal back to device, the resonant frequency of the grid was determined and then the distribution network to ground capacitive current was calculate also. Experiments indicate that the method has the characteristics of preciseness,convenience,safety in the capacitance current measurement.

关 键 词：数字信号处理器 直接数字式频率合成器 电容电流 注入信号 

分 类 号：TM935[电气工程—电力电子与电力传动] TM933