有功功率测量的异步采样方法  

Asynchronous sampling scheme for active power measurement

作　　者：徐垦[1] 程时杰[1] 

机构地区：[1]华中科技大学,武汉430074

出　　处：《电子测量技术》2007年第9期64-67,共4页Electronic Measurement Technology

摘　　要：本文提出了旨在消除同步采样条件限制的交流信号有功功率测量的异步采样方法。该方法提出了新的有功功率定义式的数值计算形式,依据交流信号一个周波内的多点采样值直接算出有功功率。采样频率只须根据存在的谐波按Nyquist定理确定,而不必满足同步采样条件。分析表明无论有无谐波,测量误差在周波内测量点数为128时约为1×10-6,且随测量点数的增大而进一步减小。依据该方法提出的算法相当简单,普通微处理器都可应用该算法连续测量每个周波的有功功率。This paper demonstrates an asynchronous sampling scheme, which can eliminate the restriction of the synchronous sampling requirement, for the measurement of the active power of the AC signal. The new numerical form of the active power definition expression has been advanced. The active power can be evaluated directly in terms of the multi-sampled data within a cycle of the AC signal. The sampling frequency is determined just according to the harmonic components existed and the Nyquist theorem, without necessity of satisfying the synchronous sampling requirement. The analysis shows the measurement error is about 1 X 10-6 whether the harmonic component exists when the sampled points is 128 in a cycle, and decreases further as the number of sampled points increases. A corresponding algorithm given in the paper is rather simple, and can be used to measure the active power of every cycle continuously with the general microprocessor.

关 键 词：异步采样 有功功率 数字测量 

分 类 号：TM933.2[电气工程—电力电子与电力传动]