基于迭代滤波的电网基波与谐波动态频率测量技术

Dynamic frequency measurement technology of fundamental and harmonic of power grid based on iterative filtering

电网存在负荷非线性、供能间歇性等特点,动态频率测量的精度易受非稳态分类和噪声等影响。文章从算法和硬件两方面研究动态频率测量技术,提出了基于复化辛普森的基波与谐波动态频率测量方法,推导了白噪声影响下的基于复化辛普森的频率测量方差公式,设计了抗干扰能力强的电网信号调理和采样电路。提出的基波与谐波动态频率测量方法采用复化辛普森积分原理,可有效消除信号中非稳态分量的影响,设计的电网信号调理和采样电路及抗干扰措施能够减少外界干扰对动态频率测量的影响。仿真结果证明了文中方差表达式的有效性。实验结果表明,提出的动态基波与谐波频率测量技术具有较高精度,满足实际测量需求。

The power grid has the characteristics of non-linear load and intermittent energy supply,and the accuracy of dynamic frequency measurement is susceptible to unsteady classification and noise.In order to solve this problem,this paper studies dynamic frequency measurement technology from both aspects of algorithm and hardware,the dynamic frequency measurement method of fundamental and harmonic method based on complex Simpson is proposed.The frequency variance expression of the proposed method under the condition of white noise is deduced theoretically.And the power signal conditioning and sampling circuit with strong anti-interference ability is designed in detail.The proposed method can effectively eliminate the influence of unsteady components in the power grid signal by using the principle of complex Simpson integral.The designed circuit and anti-interference method can reduce external interference to dynamic frequency measurement.The simulation results prove the validity of the variance expression in this paper.The experimental results show that the proposed method can achieve dynamic frequency measurement of fundamental and harmonic with high-precision,which can meet the actual measurement needs.