双频式定子接地保护的模拟滤波器设计与实现

Design and implementation of analog filter for dual-band stator ground protection

双频式定子接地保护是目前在中小型发电机中得到广泛应用的一种发电机保护,三次谐波的变化情况是这种保护动作的依据之一。文中着重就能够从发电机机端和中性点侧电压中初步提取三次谐波的模拟滤波器的设计进行了讨论,通过分析比较各类滤波器的阻带衰减速度、通频带平坦度等特点以及生产实际装置的成本等多方面因素设计出了一款能够满足保护装置要求的模拟滤波器。从仿真及实验结果中可以看出,此款模拟滤波器具有良好的应用效果。

Dual-band stator ground protection is being widely used currently in small and medium-sized generators, the behavior of third harmonic is one of the reasons which can cause the action of this protection. This article focuses on the design of analog filter which can extract third harmonic from generator terminal voltage and neutral point voltage,and designs an analog filter which satisfied the requests of equipment from analyzing and comparing the attenuation of stop band, the of flatness of pass band, the cost of equipment and any other facts of different filters. It has a good application in the result of simulation and experiment.