M A I N   N E W S

Power failure affects North India
From R. Suryamurthy and Gaurav Choudhury
Tribune News Service

NEW DELHI, Jan 6 — Several states in North India were severely affected as the power supply from Mandoli and Dadri grids in Uttar Pradesh tripped, affecting supply to the Northern Grid.

The power failure affected even the Rashtrapati Bhavan, Parliament House, Prime Minister’s residence and adjoining areas.

The most affected states were Punjab, Haryana, Delhi and Jammu and Kashmir.

The tripping in these two grids affected almost 50 per cent of the total power supply by the Northern Grid to different states. The grid’s optimum supply is 16,000 to 17,000 mw.

The additional demand for power in the region, continued cold wave conditions and dense fog, sources said, appears to be the prime reason behind the tripping of the two grids.

The demand for additional power in the region is 2000 mw.

Explaining the possible reasons behind the tripping, the sources said, in normal conditions dry air acts as an insulator. Fog, which acts as a condenser, results in sparks and its adverse impact are controlled by automatic tripping instruments. However, the continued dense fog could have resulted in frequent tripping, affecting the two grids.

“The tripping occurred at 10 a.m. and for about 15 minutes almost entire Delhi went without electricity”, Delhi Power Minister Narendra Nath told TNS.”

“The Badarpur and Rajghat grids tripped due to low frequency power supply from the Northern Grid following some fault in Dadri and Mandoli grids in Uttar Pradesh”, Dr Nath said, adding that the power supply would be normal by evening.

Sources in Power Grid Corporation said the frequency in the two grids came below the critical 47.8 cycles resulting in consequent interruption in the power supply.

Dr Nath said the Badarpur and Rajghat grids could have been affected adversely had the Delhi Vidyut Board not installed “under frequency” system in its units.

The peak demand of power for the northern region is expected to increase by 9,400 mw, which would require an additional generating capacity of about 13,000 mw within a decade. The increased power generation capacity would be in addition to covering the peak shortage of 3000 mw faced by the region at present as per the 15th power survey report.

From April to October, 1999, there was a 5 per cent power shortfall in the northern region. The requirement was 78,849 mega units whereas the availability was 63,165 mega units. The shortage during the peak time was over 15 per cent.

According to the Investment Research Information Limited, the shortfall of power for the northern region by 2002 would be minus 7.30 per cent. In 1997, the shortfall was minus 38.50 per cent.

Though the spill-over projects aggregating 5,750 mw and units which are already under construction like Nathpa Jhakri Hydel Project (1,500 mw) and a number of projects including a large number of short gestation liquid fuel-based projects, programmed to be taken up in the private sector are coming up, but the state governments’ have not drawn up programmes for commissioning these projects, the survey report said.

The report further said the power shortage conditions may have to be faced throughout the Ninth Five Year Plan period ending in 2002 as most of the projects are expected to be completed only around that time.

The transmission and the distribution system in northern India are over loaded and vary from about 20 per cent in some states to as high as 40-50 per cent in others, it said.

According to the Raja Adhyaksha Committee, the funding of the generation and distribution was to be in the ratio of 4:2:2. But fund allocation for the transmission system in Punjab had been of the order of Rs 280 crore only during the eighth Five Year Plan as against Rs 373 crore in the Seventh Five Year Plan.

The huge backlog of transmission works has led to severe overloading of the system which has affected the system parameters, such as voltage, adversely.

Cracked discs to blame
Tribune News Service

CHANDIGARH, Jan 6 — A total lack of rain in the past three months and the continuous foggy conditions in the previous fortnight may have played a significant role in today’s major power breakdown in the entire north-western region.

Going by technical reasons lack of rain can also indirectly cause harm to the power supply equipment on the power grid. The only way to avoid this is through proper maintenance of a piece of equipment called the “insulating discs”, said a source.

Explaining this phenomena top-ranked sources in the power sector said one of the major causes of tripping was the “bad conduction’’ of current through “insulating discs’’ that develop cracks in this type of weather. These brown coloured “insulating discs’’ are used to join two segments of high tension wires and are an important part of power supply equipment.

When it rains these “insulating discs’’, that are made of porcelain, are naturally washed thus the dust that accumulates is washed off. In case it does not rain during the winter the dust remains as it is. As fog descends the “insulating discs’’ get wet but are not cleaned as during a rainfall. This reaction of a mixture of dust and water from fog followed by sunlight causes cracks in the disc, an engineer explained.

Once the cracks appear the disc becomes a bad conductor of current thus leading to pressure of power supply on the high tension wires leading to frequent tripping. The layer of dust also acts as a bad conductor. While the current does not pass through the high tension wires as per the laid down specifications, the withdrawal of power at the user’s end continues. This leads to tripping, the engineer added while explaining the technical reason behind it.

Under normal circumstances these “insulating discs” should be cleaned by the respective state electricity boards who are partners on the Northern Grid. In the developed world the power companies have a system by which these “discs’’ are cleaned through machines. In our country the cleaning is still carried out by linemen, who have to climb up the poles to clean the discs. And more often than not this is one aspect that is neglected, an official added.

Tripping plays a major role in grid failures, like the one that occurred today. However, no reason has been yet assigned for the grid failure of today. The “discs” may be up to anything from 4 inches to 12 inches in diameter and a requirement to hold the wires together and prevent line losses.

This matter of dirty “insulating discs’’ causing harm to the grid has been discussed at various high level meetings of the power authorities of the region, another source added. Still an answer is to be found. While “insulating discs’’ all over the world are still made of porcelain and no other material has been found suitable.