一种高精度四点式电力信号测频新方法  

New high precision four-point frequency measurement method for power signal

作　　者：王海[1] 郑胜峰[2] 

机构地区：[1]西安电子科技大学机电工程学院测控工程与仪器系,西安710071 [2]浙江工贸职业技术学院,温州325003

出　　处：《仪器仪表学报》2012年第10期2187-2193,共7页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(10703004);中央高校基本科研业务费专项资金(JY10000904004)资助项目

摘　　要：提出了一种基于预相关处理的四点式频率测量方法。利用预相关运算降低谐波和噪声对电力信号的干扰,然后采用四点式频率估计方法消除传统三点式估计方法在某些时刻误差过大的问题。对不同A/D量化位数、基波初相角、信噪比、采样点数、谐波含量的仿真结果和对不同信噪比和谐波含量的实际测量结果表明该方法能有效地对有谐波干扰的、信噪比较低的信号进行准确地频率测量。在成本敏感的情况下,采用多重相关器,省略信号前置滤波器,避免滤波器带来的附加误差,提高测频精度。A four-point frequency measurement method of power system based on pre-correlation processing is proposed in this paper. The interferences of harmonic and noise to power signals can be reduced with pre-correlation processing. Then the four-point frequency estimation method is used to compute the frequency of fundamental signal, which avoids the overlarge errors at some instances caused by using traditional three-point estimation algorithm. Sim- ulations for different bit number of ADC quantization, initial phase angle of fundamental, signal-to-noise ratio, number of sample points and harmonic content were performed ; actual measurements were also carried out. The influence of above factors on frequency measurement precision is analyzed respectively. The simulation results and actual measurement results prove that the proposed method can effectively achieve accurate frequency measurement for the signals with harmonic interference and low SNR. In cost-sensitive cases, using muhi-correlator and omitting signal pre-fiher can avoid the additional error brought by the filter and improve the frequency measurement accuracy.

关 键 词：频率估计 预相关处理 谐波干扰 噪声 

分 类 号：TM935.1[电气工程—电力电子与电力传动]