Oscillation Detection and Mitigation Using Synchrophasor Technology in the Indian Power Grid

Low-frequency oscillations (LFOs) are inherent to power system due to its nonlinear nature. These oscillations are non-observable and not of concern if their damping is high. However, with reduction in their damping, such LFOs become observable and can result in hunting in power plants leading to large-scale blackouts. So, it is essential to monitor such LFOs in order to enhance the small-signal stability of the power system. Earlier, these LFOs were not observable from the conventional SCADA system (Supervisory Control and Data Acquisition) due to its low scan rate and skewedness. However, with the advent of Synchrophasor technology, grid operators are now able to visualize such oscillations in real time. This chapter describes the several such cases of LFOs in the Indian power system observed through Synchrophasor measurement data and their analysis. Further, it also illustrates how the Synchrophasor has enabled the grid operator in taking various remedial actions for improving the damping of the LFO.