引入超前-滞后校正的数字滤波器优化设计

Optimized Design of Digital Filter with Lead-lag Correction

为满足有源电力滤波器谐波检测的需要,提出同时加入超前和滞后校正改善低通滤波器特性的优化设计。在比较各种滤波器后,选取二阶椭圆型滤波器作为谐波检测的核心;通过分析系统零极点的分布,得出影响系统性能的参数配置关系,并加入超前-滞后校正,对数字低通滤波器进行优化。仿真试验表明,该优化设计方法能够更好地满足电网谐波和基波无功电流检测的需要,使检测系统同时获得良好的检测精度和令人满意的动态响应速度。

Aiming at the need of harmonic detection of active power filter, an optimized design is presented with adding lead - lag correction to improve characteristics of low - pass filter. Second - order ellipse filter is chosen as the core of the harmonic detection after comparing various kinds of filters. Relationship of parameters configuration which affects system performance is worked out by analyzing distribution of system pole - zero, then lead - lag correction is added to optimize low - pass filter. Simulation and experiments show that this optimized design better fits the requirements for detecting the grid harmonics and fundamental reactive current, makes the detection system may simultaneously obtain excellent accuracy and satisfactory dynamic response speed.