摘要
提出了基于重采样的谐波检测方法 ,克服了数字化谐波检测瞬时无功功率法计算量大的缺点。当信号的最高频率为 ω时 ,第 1次采样频率为 ωf≥ 4ω。需要补偿 N′次以下的谐波电流时 ,重采样频率应不小于 (N′+1 +n) ω0 (ω0 为基波频率 )。当一个周期内的采样点数为 N1时 ,重采样频率为ωmin=(N1/4)ω0 。在重采样的基础上 ,继承了瞬时无功功率理论谐波检测方法的思想——将基波电流转变成直流分量 ,据此设计了一个数字谐波检测系统。仿真实验表明 ,该系统既具有数字系统的准确性和稳定性 ,又克服了数字滤波器计算量大和实时性差的问题 。
A method for harmonic detecting based on resampling theory is proposed. It can improve the dynamic characteristics of digital filters. If the highest frequency in signal spectrum is ω the first sampling frequency will be ωf≥4ω. When the active power filter (APF) is designed to compensate N'th harmonic currents, the resampling frequency can not be less than (N'+1+n) ω0, (where ω0 is the fundamental frequency). If the sampled data is N1 in a period, the resampling frequency is ωmin=(N1/4) ω0, Furthermore, a digital harmonic detecting system based on resampling, inheriting the core idea of the instantaneous detecting method, is designed. That is, transform the fundamental currents into DC component. Simulation shows that this system not only has accuracy and stability, but also overcomes the long existent shortage of large amount of calculation for the design of digital filter and poor on-line response characteristics and bad dynamic following performance.
出处
《电力系统自动化》
EI
CSCD
北大核心
2003年第12期45-47,共3页
Automation of Electric Power Systems
关键词
谐波测量
有源滤波器
重采样
频谱混叠
Dynamic response
Harmonic analysis
Reactive power
Sampling
