The frequency profile of the all-India grid showed some improvement in frequency profile in August 2021, according to latest statistics released by Power System Operation Corporation Ltd (POSOCO).
In its latest statistical report, POSOCO, which manages the National Load Dispatch Centre (NLDC), said that the average frequency of the national grid stood at the desirable level of 50.00Hz.
The grid frequency was in the optimum band (as prescribed by The Indian Electricity Grid Code or IEGC) of 49.90Hz and 50.05Hz in 76.93 per cent of the total time. This was remarkably better than the performance in the preceding months. In July 2021, for instance, the aforementioned IEGC-prescribed band was seen in 75.06 per cent of the time. In June 2021, this metric was 74.52 per cent. (See table).
During the first five months of FY22 (April to August 2021), the average national grid frequency was 50.00 Hz, with minimum and maximum frequency standing at 49.51Hz and 50.30Hz. The optimum band of 49.90-50.05Hz was seen in 75.19 per cent of the time.
Voltage profile
The voltage profile across all substations of the National Grid was generally stable during August 2021. With the exception of a few substations, there was no major deviation from the rated substation voltage. Some such exceptional substations were Vemagiri (765kV, Andhra Pradesh) and Cuddapah (765kV, Andhra Pradesh).
In each of the two cases, the substation voltage was found to be outside the IEGC band for around 75 hours during August 2021. Across all national grid substations, the total number of hours where voltage was outside the IEGC band stood at around 320 hours.
Outages
NLDC monitored 50 grid outages (line tripping) in interregional transmission elements, while around 34 outages were seen in transnational lines (between Bangladesh, Bhutan and Nepal). In July 2021, the number of grid outages in interregional transmission elements stood higher at 73.
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POSOCO
Power System Operation Corporation Ltd (POSOCO) manages the National Load Dispatch Centre (NLDC) and five regional load dispatch centres (RLDCs). POSOCO was formed in March 2009 as a wholly-owned subsidiary of PGCIL. However, in early 2017, POSOCO was converted into an independent entity directly under the Union power ministry. Till March 2009, it was PGCIL that performed the functions and duties now done by POSOCO.
