改进型FBD谐波检测法在有源滤波器中的应用

论述了FBD(Fryze-Buchholz-Dpenbrock)谐波检测法的基本原理,针对FBD法受限于锁相环电路以及滤波环节存在的不足做出了改进。首先设计了一种基于电压序列分解原理的基准电压提取方法,得到与基波正序电压同频同相的电压信号代替锁相环的作用,提高了检测精度且易于实现;其次使用滑窗迭代DFT(discrete fourier transform)滤波模块替代低通滤波器,同时利用小波变换对各相谐波的细节部分进一步完善,提高了滤波环节的实时性和准确性。最后通过仿真分析,验证了改进方法的正确性和优越性。

Application of Improved FBD Harmonic Detection Method in Active Power Filter

The paper analyzed the basic principle of FBD harmonic detection method, and improves the limitation of FBD method in PLL circuit and filter link. Firstly, a reference voltage extraction method based on the principle of voltage sequence decomposition was designed, and the voltage signal with the same frequency and same phase as the fundamental positive sequence voltage was obtained instead of the phase-locked loop, which improves the detection accuracy and easy implementation. Secondly, the sliding window iterative DFT filter module was used to replace the low-pass filter, and the wavelet transform was used to further improve the details of each phase harmonics, which improves the real-time and accuracy of the filtering link. Finally, the correctness and superiority of the improved method were verified by simulation analysis.