Brownout in Southern Part of North Eastern Region (NER) Grid of India

This paper attempts to highlight a case of Brownout due to voltage instability observed in the Southern part of NE Region (NER) Grid of Indian Power System on 23.09.2017. As per network configuration, Palatana generation was the major source of Reactive Power for Southern part of NER Grid. Outage of 2 x 125 MVA, 400/132 kV Palatana ICTs impacted the Reactive Power Balance in Tripura Power System as the demand for Reactive Power in Tripura Power System could not be compensated either by internal generations or by long 132 kV Tie Links connecting Power System of Tripura with rest of the NER Grid. Consequently, voltage deteriorated to as low as 4 kV as observed at Phasor Measurement Unit (PMU) installed at 132 kV Agartala substation. The paper presents the relevant system studies conducted using PSS@E software considering the network configuration at the time of the event. Suggested measures for mitigating such type of brownout event in the near future are highlighted as well.