No lessons learnt from past says CEA report

Indeed, Srivastava’s report is very similar to previous reports made when the Northern Grid collapsed on January 1, 1997 or when the Eastern Grid collapsed on July 25, or any of the nine or ten occassions when a major grid collapse took place in the last seven years.

Srivastava’s report for instance points out that the circuit breakers of 132 KV at Rihand-Singrauli line were not functional — in each of the previous cases of grid collapse it has been found that the State Electricity Boards (SEBs) disconnect the relays manually, or they are in a state of disrepair (this helps the SEBs to draw excess power from the grid even when this causes the grid frequency to dip to unsafe levels). When the Central Electicity Regulatory Commission (CERC) conducted an inquiry into the Eastern Grid’s collapse of July 25, it had also found that the SEBs had disconnected the underfrequency relays!

Srivastava has now directed the Northern Regional Electricity Board to formulate within one week a time bound action plan for installation of the underferquency relays throughout the grid.

Srivatava also found that ‘free governors’ at various power generating stations were either not functioning or not in place — this allows generators to continue producing power even when the grid frequency rises sharply. According to the report " governors provided on the renovated Bhakra machines need to be properly tuned by Bhakra Beas Management Board (BBMB)".

And though Srivastava doesn’t go into the causes for why Powergrid failed to manage the grid frequency effectively, this newspaper had given details on January 5. On the night of January 1 and the early morning of January 2 when the Northern Grid developed problems, Powergrid (through its Northern Regional Load Despatch Centre) asked the Uttar Pradesh government’s Anpara Thermal Power Station to cut production by 400 MWs and NTPC’s Singrauli Thermal Power Station was asked to back down production to 1320 MWs. Anpara, however, disobeyed instructions and cut production by only 150 MW, while Singrauli continued to produce around 1500 MWs. Understandly, Powergrid was unable to keep the grid fequencies stable and the grid collapsed.

Srivastava’s report also holds Powergrid and BHEL responsible for the poor functioning of the Rihand Dadri HVDC line which is the backbone of the northern grid. The report points out that from December 14, 2000 one pole of the Rihand Dadri HVDC line had been out of service due to failure of the converter transformer. This restricted the transmission capability between the Eastern and Western part of the northern grid.

Four of BHEL’s transformers on this line have developed serious problems in the last four months and BHEL says that they cant repair the faults before March–April.

Later, Suresh Prabhu, who had ordered a thorough probe within hours of breaking down of Northern Grid, announced 27 corrective measures on the basis of the Srivastava Committee report.

On the punitive action to be taken against any agency responsible for the failure, Prabhu said "we are referring the matter to CEA to decide at the eraliest." He, however, did not specify any time frame for CEA to give its recommendations on the above matter.

Lessons not learnt
Power producers didn’t cut production despite the grid frequency rising to unsafe levels.
State Electricity Boards didn’t cut consumption despite the grid frequency falling to unsafe levels.
Faulty equipements not replaced in time.
No mechansim to ensure that Powergrid’s instruction are complied with quickly.