Dense fog leads to tripping at Lehra Mohabbat thermal plant

Dense fog has not only thrown normal life out of gear but it has also led to disruption in power supply in the state.

All the four units of Lehra Mohabbat thermal plant tripped early morning on Wednesday following the tripping of 220 KV transmission lines due to dense fog in the area.

The tripping of 220 KV Lehra Mohabatt-Barnala lines due to foggy weather led to the tripping of 250 MW unit 4 at 2.51am followed by tripping of two 210 MW units at 3.37am.

Due to fog, breaker insulator of unit 4 and 1 also got burst. Unit 3 tripped subsequently at 9.12am.

According to thermal plant officials, engineers were able to synchronise unit 2 at 12.45pm followed by synchronisation of unit 3 at 1.50pm.

Due to tripping at Lehra Mohabatt plant, the industry faced the brunt because of outage of power supply in the early hours. As the power demand these days is low, there was no major problem for the PSPCL to meet the required demand and bring the situation under control.

"The fog disturbs the lines as it creates a conducting path and leads to tripping. Our engineers brought back the unit back into operation within a few hours. One unit is still boxed down as there is no demand of power in Punjab", said GS Chhabra, Director (Generation) PSPCL.

Meanwhile, the Metrological Department has predicted more dense fog in the coming two days.

Ironically, in 2010 winter, the northern grid had collapsed due to heavy fog in the region.

How fog disrupts power supply

Fresh air works as an insulator. However, the fog, which comprises vapours of water mixed with pollutants and dust, works as a conductor of electricity. The density of fog is crucial since air is an insulator and if there are too much air spaces between water particles suspended in the fog, then electricity doesn't get conducted as efficiently. If fog is dense then current can pass at least a short distance through it. And that trips the feeder lines of high voltage.