UPCL(Uttaranchal power corperation limited) de-mergedfrom UPPCL on 12 th feb 2001.It is renamed as Uttarakhand power corperation ltd. On 1 stjanuary 2007 as the functional bi-furcated utilitiesresponsible for the electricity distribution and powertransmission within the periphery of state.Today, it operates and maintains the substations of66/33/11 KV and distribution substations of 11/0.4 KV.
UPCL is committed to provide high reliability and qualitypower supply to electricity consumers spread across the 13districts of the state.Its aim is to reduce the AT and C losses to 20% by march2013.
An electrical substation is a subsidiary station of an electricity distribution system where voltage is transformed from high to low or vice versa using transformers. Electric power may flow through several substations between generating plant and consumer, and may be changed in voltage in several steps.
There are two types of substations constructed in UPCL- Indoor substation Outdoor substation As per standard design the switchyard of the outdoor type should be 30*20 mtrs. The capacity of 33/11 KV substation should be 3MV, 5MV, 8MV,10MV as per load demand.
In an indoor substation, all the equipments are mounted indoor. Safer than outdoor substation. Require less area for switchyard.
In an outdoor substation, all the equipments are mounted outdoor. Required standard size for switchyard.
Current transformer Power transformer Line isolators Circuit breakers Fuse set Lightning arresters Insulators
Current transformers are basically used to take the readings of the currents entering the substation. This transformer steps down the current from 800 amps to1amp. This is done because we have no instrument for measuring of such a large current.
Potential transformer basically used for the transformation of voltage from higher value to lower value. It is also known as instrument transformer.
The line isolators are used to isolate the high voltage flow through the line into the bus. This isolator prevents the instruments to get damaged. It also allows the only needed voltage and rest is earthed by itself.
A circuit breaker is an equipment, which can open or close a circuit under normal as well as fault condition. These circuit breaker breaks for a fault which can damage other instrument in the station.
It is an instrument that blown when too much current flows, which interrupts the circuit in which it is connected. Short circuit, overload or device failure is often the reason for excessive current.
It is a device used in electrical power system to protect the insulation from the harmful effect of lighting. It can resists or ground the lighting if falls on the feeders.
The insulator serves two purpose. They support the conductor and confine the current to the conductor. They are used to contain, separate or support electrical conductors on high voltage electricity supply networks.
Most of the lines have to pass through forest area and it take a considerable time to obtain the approval from the forest department. The head load cartage of material takes time in transportation up to site. Due to its extreme weather conditions of some areas, maintenance cost increases.