HIMACHAL PRADESH STATE ELECTRICITY BOARD LTD. 220 kV GRID SUBSTATION JASSUR , KANGRA (H.P.) Prepared by: Rupesh Mankotia 245/09 5th semester

INTRODUCTION About substation The substation in Jassur is one of the largest power capacity grid substation in H. P. . It has installed capacity of 220kV , which is taken from three feeders. 1.) Pong dam 2.) Baira Suel 3.) Ranjit Sagar Dam / Thein dam This 220 kV is step down to 132 kV, 33kV ,11 kV and distributed to nearby areas. Instruments like circuit breakers , lightning arresters , wave traps , bus bars ,instrument transformers are used.

SALIENT FEATURES OF GRID SUBSTATION , JASSUR Installed capacity of substation - 181.5MVA Transmission line feeding substation - 220kV AC Brief specification of a transformer 1No. 25/31.5MVA  220/33KV  3Phase power transformer 4No. 40/50MVA  220/132KV  1Phase power transformer 1 No. 10 MVA + 1 No. 5 MVA  33/11KV  3Phase power transformer  Types of breakers – 220kV SF6 gas circuit breaker 132kV SF6 gas circuit breaker 33kV minimum oil circuit breaker 11kV vacuum circuit breaker Number of 132kV out going bays - 4 Number of 33kV out going bays - 6 Number of 11kV out going bays – 8 Area fed from substation – Nurpur , Jawali , Indora , (Kangra) and whole of distt Chamba

POWER LINE CARRIER COMMUNICATION used for telecommunication ,telemonitoring between electrical substations , through power lines at high voltages uses amplitude modulation technique Capacitor Voltage Transformer are used for PLCC transmit communication signal and 50/60 Hz power signal through same electric power cable SLDC (State Load Dispatch Center ) get information by using PLCC communication

WAVE TRAP connected in series with the power transmission line It blocks carrier frequency/waves (24 kHz to 500 kHz) on line It allows power waves (50-60 Hz) to pass through it.

LIGHTNING ARRESTERS It is a device used to protect the electric system from damaging effects of lightning. lightning surge travels down the power system to the arrester This surge current diverted around the protected insulation to earth.

INSTRUMENT TRANSFORMER CURRENT TRANSFORMER POTENTIAL TRANSFORMER

CURRENT TRANSFORMER used for measurement of electric currents. CT produces a reduced current accurately proportional to the current in the circuit isolates the measuring instrument from high voltage circuit. used in metering and protective relays.

POTENTIAL TRANSFORMER are used to step down the voltage for: Measurement Protection Control allows protective relay equipment and measuring instruments to be operated at a lower voltages.

Circuit breaker An automatically operated switch protect an electrical circuit from overload and short circuit It is an on – load device Classified as: Low voltage circuit breaker High voltage circuit breaker Miniature circuit breaker ( an example of low voltage circuit breaker)

Gas circuit breaker (SF6 ) have excellent dielectric and arc quenching properties arc is cooled by a gas blast of sufficient intensity excellent thermal stability 100 times more effective than air in quenching arcing SF6 circuit breaker is more efficient and reliable. SF6 ( Sulphur Hexafluoride) circuit breaker at 132 kV side in Jassur grid substation

Vacuum Circuit Breaker two electrical contacts are enclosed in a vacuum One of the contacts is fixed, other is movable during fault movable contact pulls away from the fixed contact, thus interrupting the current are very durable designed to last for an extended period of time.  Vacuum circuit breaker used for 11 kV distribution at Jassur grid substation

Isolator used to completely de-energise the circuit for service or maintenance have provisions for a padlock  an isolator is an off-load device  .

Battery Bank Dc supply is necessary for the operation of the relays The battery bank used in this substation is of 220V 110 cells is connected in series each of 2V A number of batteries connected in series

220 /33 kV 25/31.5 MVA transformer no. 1 at jassur substation BUCHHOLTZ RELAY BUSHINGS CONSERVATOR TRANSFORMER TANK BREATHER

Transformer Tank whole assembly of a transformer is placed in a metal sheet tank assembly of the transformer is immersed in an oil which act as an insulator as well as coolant. The oil will take out the heat produced by the transformer windings and core

Conservator A cylindrical shaped air tight metal drum placed on a transformer tank It provide cooling to transformer It provide insulation between transformer windings. Both OLTC (on load tap changer) and main tank’s oil are separated to avoid mixing of their oils

Breather apparatus with which breathing of the transformer takes place SILICA GEL (DRY) apparatus with which breathing of the transformer takes place Oil is used to trap the dust particles , during contraction of oil & suction of outside air to inside of transformer OIL A Breather

Buchholz Relay It gives an alarm to the operator if there is any fault in transformer If fault continues to persist , then the relay will trip the main circuit breaker to protect the transformer It works during: Short-circuited core laminations Broken-down core bolt insulation Bad contacts Overheating of some part of the windings Short-circuits between phases Earth faults puncture of bushing insulators inside tank

Methods of cooling of tranformer Air natural (AN) Air Blast(AB) Oil Natural (ON) Oil natural air forced (ONAF) Oil natural water forced (ONWF) Forced circulation of oil Oil forced air natural (OFAN) Oil forced air forced(OFAF) Oil forced water forced(OFWF) ONAF cooling provided to 220/33kV transformer

RADIATOR Radiator are used in transformers to cool the transformer oil ON & ONAF is used for cooling It has small fins 4 – 10 radiator banks in a transformer depending upon capacity

The company is performing well their duties CONCLUSION   The company is performing well their duties Minimizing cost of generation State Electricity Board is a competent organization and has infrastructure to take up any challenges I am pleased to have learnt a lot about the work culture and ethics of an organisation