The Managing Director of BESCOM, Mr Manivannan, has been spearheading a movement on FaceBook, to bring various facets of this hitherto opaque Government organization to the public. Various initiatives have been launched, and the latest is his attempt to describe how electricity makes it into our homes from where it is generated. Here is the process, in his own words:
HOW does electricity, generated at the Raichur Thermal Power Plant (RTPS) come to your home in Bangalore? It’s interesting and important to know how electricity reaches your home. It may explain you why the supply is cut off at times, and it will also enable you to advise/suggest ways for improvement. The electricity generated at RTPS (or any other station) reaches your house in five steps.
1. Transmission from RTPS to Bangalore. The transmission of electricity happens at a very high voltage, 400 kilovolts (4,00,000 volts!). The huge towers one sees when one drives through Neelamangala/Peenya, are the towers that carry electricity at 400 KV. These lines end up at huge stations, called Master Receiving Stations. These receive the electricity at 400 KV, and they then reduce the voltage to 220 KV, using huge transformers in the station. These transformers are called power transformers. They are of 500 MW capacity, enough to power almost 1/4th of Bangalore city, and as huge as your drawing room! For Bangalore city, we have 3 such 400 KV Master Receiving stations: Nelamangala in the North, Hoody in the east, and Somanahalli in the south. When these stations trip, we have major outage in the city.
2. From these Master Receiving Stations, the electricity comes out at 220 KV, and it is sent to Receiving Stations, which are situated inside the city at different locations. In the Receiving stations, the electricity is further reduced to 66 KV. Yes, as you guessed, here also we have same Power Transformers, which reduce the voltage from 220 KV to 66 KV. We have 15 such Receiving stations in Bangalore.
3. Now, the electricity, reduced to 66 KV , goes from the Receiving stations to the sub-stations. These transmission can be done through smaller towers, or even underground via UG cables). The sub-stations receive the electricity at 66 KV, and reduce it to 11 KV, again using similar transformers There are 90 such sub-stations in the Bangalore city itself!
4. Electricity leaves the sub-station in trunk lines, called ‘Feeders’. Each sub-station has 10-15 such trunk lines emanating from it, and the lines branch to different locations around the sub-station. These feeders end up in DTCs (Distribution Transformer Centers), which are commonly called just ‘transformers’ which we keep seeing everyday at the side of the roads. These transformers, in turn, reduce the voltage to 440 volts.
5. These 440 volt lines, which emanate from your neighborhood transformers, come to your home meter/switch board mains finally. In these 5 steps, electric power flows through 1000 of kilometers, or lines, and hundreds of nuts and bolts. If, at any point, there is a loose connection of fault, then you have an outage. In this journey, the first 3 steps come under the jurisdiction and control of Karnataka Power Transmission Company Ltd (KPTCL). Thus any fault till 66 KV is attended by them. The last 2 steps come under BESCOM. That is, from the sub-station to your home. Thus, providing power to you 24×7 requires all the three to work in tandem; the RTPS, the KPTCL and the BESCOM. All of us work round the clock, to ensure 24×7 power supply to you. And yes, we feel pride in serving you!:) Thanks to Antony Dass T for this pictorial representation: ⊕