Improvement of timing reliability and data transfer security of synchrophasor measurements

Synchronized phasor measurements are becoming one of the key measurement elements of wide area measurement systems in advanced power system monitoring, protection, and control applications. Availability of global positioning system (GPS) provides the possibility of wide-area deployment of Phasor Measurement Unit (PMU) and Frequency Disturbance Recorder (FDR) in power system. GPS is the only timing source for PMU and FDR so far, and they will cease to work when GPS signal is lost or unstable. In addition, phasor data is transferred over the Internet without any encryption, which exposes data to cyber-attacks. The purpose of this paper is to develop an alternative GPS independent timing synchronization method for PMU and FDR, and to implement an encryption system without disrupting real-time data delivery. Primary test results confirm improvement of timing reliability and data transfer security of synchrophasor measurements.