Off-line event filter for the wide area frequency measurements

System-wide frequency is one of most important vital signs of power system. To better understand the dynamics of large power systems, wide-area, synchronized monitoring of system frequency is needed. The concept of an Internet based, real-time, GPS synchronized, wide-area frequency monitoring network (FNET) was proposed in 2000. Today, FNET consists of more than 30 frequency disturbance recorders (FDRs) throughout the US with an information management system (IMS) based at Virginia Tech. In the near future, more FDRs will be deployed. With the help of FNET, a wide-area power system disturbance event filter has been developed. The filter helps pick out the disturbances from massive amounts of daily monitoring data and collect valuable information for the disturbance analysis.