Analyses of Indian Power System Frequency

Frequency is a vital indicator for the reliable operation of power systems. The frequency of major power systems around the world vary only slightly around the nominal frequency. The variation is mostly on account of dynamically changing demands, changes in generation and variation of renewable generation with increasing penetration of renewable energy based generation. The various controls have been put in place to control the variations in frequency. The quality of frequency is of importance to system operators as the various frequency control measures operate as per the settings identified by them. The variations in frequency affect the dynamics of power system and require analysis of past data to arrive at effective conclusions. The behavior of frequency in different time scales ranging from minutes of an hour to months of a year has been found to have a definite pattern. The analysis of pattern so derived can be a vital input in short, medium and long term operational planning. The Phasor Measurement Units (PMU) help in providing high resolution accurate data from various locations in a power system. This paper presents the analysis of Indian Power system frequency of 5 years and derives important conclusions.