Implementation and applications of a Wide Area Frequency Measurement System synchronized using Network Time Protocol

A Wide Area Frequency Measurement System synchronized using Network Time Protocol (NTP) has been implemented at several locations in the Indian grid. Although the synchronization accuracy of a NTP-synchronized system cannot match that of a GPS system, it is adequate to accurately capture electro-mechanical transients like inter-area power swings. This system has been successfully used to monitor events occuring in the grid, including the loss-of-synchronism during the partial blackout of 30^th July 2012 in India. It has also been possible to apply power swing damping estimation algortithms to the data. The results match well with those obtained from GPS synchonized PMU data. For these applications, the NTP based system is a viable, low-cost and easy-to-deploy alternative to a PMU system.