基于小波包多频带分解实现谐波抑制与无功补偿

Multi-bands Decomposition Based on Wavelet Packet Algorithm for Harmonic Suppression and Reactive Power Compensation

提出一种子频带分解实现多通道有源滤波与无功补偿的新方法。该方法根据无功和谐波的频域分布特性,将补偿容量按频带分配到各子通道,不同通道采用不同功率模块予以补偿,避免了电力电子器件开关频率与功率等级的矛盾。该文讨论了小波包滤波器组算法实现多通道子带滤波方法的补偿原理,分析了循环缓存实现周期边界延拓方式在系统频率波动时的检测结果,并提出锁相环(PLL)调整缓存深度的解决方案。仿真结果表明,该方法具有较好的动静态性能,同时能够补偿三相不对称的负载电流畸变分量,适合应用在大容量有源滤波与无功补偿的场合。

A novel periodized extension wavelet packet （WP） based sub-bands approach for multi-channel harmonic suppression and reactive power compensation is presented and analyzed. This technique distributes power rating into separated channels in frequency domain according to the characteristics of reactive power current and dominant harmonics. Based on this approach, the multiple power modules avoid the conflict between power rating and switching frequency of power electronic unit. The principle of the WP filter bank based decomposition algorithm is discussed, the influence of system frequency fluctuating on circle buffer realized periodized extension scheme is analyzed, and an approach using phase-lock loop （PLL） controlled circle buffer to overcome this problem is presented. Simulation results show good steady-state and dynamic performance of the proposed approach, even when the distorted currents are three-phase unbalanced. The proposed scheme is suitable to implement harmonic suppression and reactive power compensation in high power applications.