基于小波变换的自适应电网频率测量算法

Adaptive Frequency Measuring Algorithm Based on Wavelet Transform

传统的最小均方频率跟踪算法在谐波干扰较严重时存在收敛速度较慢、误差较大等问题。提出了一种以小波变换理论为基础的自适应频率测量算法。该算法对检测到的电网电压信号进行小波分解,弱化信号间的相关性,提高算法的收敛速度,同时将信号分解到不同的频段,减小谐波干扰对测量结果精度的影响,设计两级自适应滤波器系统跟踪测量电网频率。通过仿真实验验证,该算法可快速地跟踪测量电网频率,且在信号受谐波干扰较严重的情况下仍具有较快的收敛速度和较高的测量精度。

Harmonic may distort the convergence speed and accuracy of LMS algorithm. This paper proposes a new fre quency measuring algorithm based on wavelet transform. This new method using wavelet transform to weaken the correla- tion of the signals to improve the convergence speed,while the signal is decomposed into different frequency bands to im prove the accuracy of measurement results, design two stages adaptive filter system tracking and measuring grid frequen- cy. According to the simulations, the proposed algorithm can precisely and quickly trace the grid frequency, and still has fast convergence speed and high accuracy in more serious cases harmonic interference.