An evaluation of network time protocol for clock synchronization in wide area measurements

To study and gain a better understanding of the power system dynamics, the concept of building a frequency monitoring network (FNET) was proposed in 2000 [1] and has been realized in 2003. The FNET system consists of many high dynamic precision frequency and phasor estimation devices, also known as frequency disturbance recorders (FDR). These FDRs can be used at any 110 V or 220 V wall outlet and transmit measured data remotely via the Ethernet. The FDRs can measure power system parameters including frequency, voltage, and phase angle. There are currently more than 40 FDRs placed strategically in different locations within the North America power grids to monitor the entire power network. Furthermore, the FDRs are currently synchronized in time via a GPS receiver. This paper discusses the feasibility study of the Internet timing synchronization. The motivation for Internet timing synchronization was ignited during the research for a more portable and economical yet still highly accurate FDR design. Test results are presented from several different NTP implementation methods. Based on the correlation between time synchronization and phasor accuracy, it was concluded that the current NTP is not yet a feasible synchronization tool for accurate phasor measurement.