基于n阶LMS自适应滤波的改进型谐波检测方法

Improved Harmonic Detection Method Based on n-order LMS Adaptive Filtering

通过分析多种谐波检测方法,提出一种FBD法和ip-iq法相结合的谐波电流检测方法 ,并对低通滤波环节进行改进。首先设计了一种在三相四线制系统中计算相对简单的谐波电流检测方法,在降低算法复杂性的同时保障了灵活性;其次使用添加了闭环回路的n阶LMS自适应滤波算法模块替代低通滤波器模块,能把测得的基波电流反馈到输入电流中,增强了滤波环节的跟踪速度和动态特性;最后通过仿真验证了改进的谐波电流检测方法的优越性和精确性。结果表明,该方法具有较高的应用价值。

Based on the analysis of various harmonic detection methods, a harmonic current detection method was proposed by combining the FBD and ip-iq method. The low-pass filter was improved. First, a relatively simple harmonic current detection method for three-phase four-wire system was designed, which not only reduces the complexity of the al- gorithm, but also guarantees the flexibility. Then, an n-order LMS adaptive filter algorithm modules with added closed- loop was used to replace the low-pass filter modules to feedback the measured fundamental wave current to the input current, which enhances the tracking speed and dynamic characteristics of the filter link. Finally, the superiority and accuracy of the improved harmonic current detection method were verified by simulation techniques. The results show that the method has high application value.