INDUSTRIAL TRAINING AT UPPCL

132 KV ,NAINI COMPLEX ALLAHABAD BY AMIT KUMAR YADAV

SINGLE LINE DIAGRAM OF 132 KV NAINI COMPLEX SUBSTATION

GUG

WHAT IS SUBSTATION?

  Substation:- Substation is an intermediate switching, transforming or converting station between the generating station and the low tension distribution network situated generally near consumer’s load centre.

Function of the substation:- The sub-station receives power from the generating station by a single or more feeders at a high voltage, transform the same to the different distribution voltages and sends to different consumers through distribution network.

Major components of 132 kv s/s

1. Power transformer 2. potential transformer 3. current transformer 4.circuit breakers 5.lightening arrestors 6. protective relays 7. Isolators

RATINGS OF 40 MVA TRANSFORMER1.RATED POWER : 40 MVA2.RATED VOLTAGE AT NO LOAD:

132/33 KV3.RATED LINE CURRENT : 175/700 A4.FREQUENCY: 50 Hz5.TOTAL MASS:83370 Kg6.GURANTEED MAXIMUM

TEMPRETURE RISE: 50 DEGREE CELSIUS FOR OIL,

55 DEGREE CELSIUS FOR WINDING

7. TYPE OF COOLING : OIL NATURAL AIR

FORCED

CURRENT TRANSFORMER A current transformer (CT) is used for measurement

of alternating electric currents. When current in a circuit is too high to apply directly

to measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to measuring and recording instruments.

A current transformer isolates the measuring instruments from what may be very high voltage in the monitored circuit.

The primary circuit is largely unaffected by the insertion of the CT. The rated secondary current is commonly standardized at 1 or 5 amperes. For example, a 400:1 CT secondary winding will supply an output current of 1 amperes when the primary winding current is 400 amperes.

SPECIFICATIONS Highest system voltage : 145 kv Rated primary current : 800 A turns ratio : 400-200-100A/1 A

POTENTIAL TRANSFORMER

Potential transformers (PT) (also called voltage transformers (VT)) are a parallel connected type of instrument transformer.

They are designed to present negligible load to the supply being measured and have an accurate voltage ratio and phase relationship to enable accurate secondary connected metering.

SPECIAFICATIONS Highest system voltage : 145 kv Primaryy voltage : 76.21 kv Class : 3 phase

RELAYS Primary sensing unit It operates when a current

reaches above a specified limit.

Its gives signal to CB to operates to prevent the power system from damage.

Types: 1. DIFFERNTIAL RELAYS 2. OVERCUURENT RELAY 3.DIRECTIONAL RELAY 4.DISTANCE RELAY

CIRCUIT BREAKERS

According to their arc quenching media the circuit breaker can be divided as-1.Oil circuit breaker2.Air circuit breaker3.SF6 circuit breaker4.Vacuum circuit breaker

LIGHTNING ARRESTOR A lightning arrester is a device

used on electrical power systems and telecommunications systems to protect the insulation and conductors of the system from the damaging effects of lightning.

The typical lightning arrester has a high-voltage terminal and a ground terminal.

When a lightning surge (or switching surge, which is very similar) travels along the power line to the arrester, the current from the surge is diverted through the arrestor, in most cases to earth.

ISOLATORS It is an off-load device. Even though, isolators is a switch, it is

not used as a normal on off switch. It is used only when the electrical

system has to be disconnected from the main supply, to perform maintenance or related activities, which involve direct contact with the current carrying components of machinery.

Isolators may provide additional safety features like, when switched off the trapped charge will be ground through a ground terminal in the isolator.

Isolators are normally placed after the circuit breaker allowing the internal circuit to be disconnected from the main supply without affecting the breaker.

A SPECIAL THANK FOR TO ALL