MADAN MOHAN MALAVIYA UNIVERSITY OF TECHNOLOGY

SUMMER TRAINING REPORT

ON

400KV SUBSTATION

UTTAR PRADESH POWER TRANSMISSION CARPORATION LIMITED

MOTTIRAM ADDA,GORAKHPUR(U.P.)

SUBMITTED BY: ANUJ BANSAL

FINAL YEAR(1204220007)

CONTENTS

ELECTRICAL SUBSTATION GORAKHPUR SUBSTATION INCOMING AND OUTGOING OF SUBSTATION TRANSFORMER COOLING FANS CURRENT TRANSFORMER CAPACITOR VOLTAGE TRANSFORMER CIRCUIT BREAKER ISOLATOR LIGHTNING ARRESTER RELAYS WAVE TRAP BATTERY ROOM SINGLE LINE DIAGRAM REFERENCES

ELECTRICAL SUBSTATION

An electrical substation is a subsidiary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers.

Depending on its purpose it can be of many types. For example transmission or distribution type.

GORAKHPUR 400KV SUBSTATION Location: Nearby cities- Gorakhpur,

Deoria, Khalilabad Coordinates: 26°41'3"N 83°30'18"E The whole substation is divided in two

parts: 400kv & 220kv site. Two 165MVA 220/132kV transformers

and one 315MVA 400/220kV transformer, one 250MKV autotransformer, Two 31.5MVAr shunt reactor,15 lighting tower,SF6 circuit breaker, Capacitor voltage transformer(CVT) Current transformer(CT).

400kV Incoming 1. PGCIL I 2. PGCIL II (GIDA Sahjanwa) 3. UPPCL Azamgarh 

220kV Outgoing  1. Deoria 2. Baraunhua

TRANSFORMER

A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Commonly, transformers are used to increase or decrease the voltages of alternating current in electric power applications.

This substation has two types of transformer:-

Two 165MVA 220/132kV transformers and one 315MVA 400/220kV transformer

COOLING FANS

Cooling fans are used for forced air cooling of the transformer

165 MVA uses six cooling fans

315 MVA uses eight cooling fans

All fans not start at the same time. They start in pairs.

CURRENT TRANSFORMER In electrical engineering, a current transformer(CT) is used for measurements of

electric currents.Current transformers, together with voltage transformers(VT)(potential transformers(PT)), are known as instrument transformers.

When current in a circuit is too high to directly apply measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to the measuring and the recording element.

CAPACITOR VOLTAGE TRANSFORMER A capacitor voltage transformer (CVT) is a transformer used in power systems to step-

down extra high voltage signals and provide low voltage signals either for measurement or to operate a protective relay.

In its most basic form the device consists of three parts: two capacitors across which the voltage signal is split, an inductive element used to tune the device to the supply frequency and a transformer used to isolate and further step-down the voltage for the instrumentation or protective relay.

CIRCUIT BREAKER A circuit is a automatically operate switch designed to protect

the system during shortcircuit or abnormal conditions. Below shown is of SF6 circuit breaker.

ISOLATORS In electrical

engineering, a disconnector, disconnect switch or isolator switch[1] is used to ensure that an electrical circuit is completely de-energized for service or maintenance.

Such switches are often found in electrical distribution and industrial applications, where machinery must have its source of driving power removed for adjustment or repair.

LIGHTNING ARRESTER Surges, or transients, are brief

overvoltage spikes or disturbances on a power waveform that can damage, degrade, or destroy electronic equipment within any home, commercial building, industrial, or manufacturing facility.

The overvoltage protection is obtained by the use of lightning/surge arresters.

Lightning Arresters or Surge Arresters are always connected in shunt to the equipment to be protected, they provide a low impedance path for the surge current to the ground.

Mostly in present days zinc oxide(Zno) gapless arresters are in use

RELAY In electrical engineering, a

protective relay is a device designed to trip a circuit breaker when a fault is detected.

The first protective relays were electromagnetic devices, relying on coils operating on moving parts to provide detection of abnormal operating conditions such as over-current, over-voltage, reverse power flow, over- and under- frequency.

Microprocessor-based digital protection relays now emulate the original devices, as well as providing types of protection and supervision impractical with electromechanical relays

BUCHHOLZ RELAY

In the field of electric power distribution and transmission, a Buchholz relay is a safety device mounted on some oil-filled power transformers and reactors, equipped with an external overhead oil reservoir called a "conservator".

The Buchholz relay is used as a protective device sensitive to the effects of dielectric failure inside the equipment.

Buchholz relays have been applied to large power transformers at least since the 1940s, and are connected between the conservator and oil tank of a transformer

WAVE TRAP

Wave trap are used for carrier communication.

It traps the higher frequency above 50 Hz.

It is the effort to utilize the same transmission line between to substation for the purpose of communication

WORKING

BATTERY ROOM The control panels and relays of the substation require DC supply

of 220 V. This DC supply is made with the help of battery bank reserve normally kept in a separate room called Battery room.

The batteries used in this substation are Nickel-Cadmium (Ni-Cd) batteries.

CONTROL AND RELAY ROOM The control room has various control panels

which shows the information like incoming power, outgoing power, frequency, time common to all substations, status of various lines (healthy, faulted, under outage or maintenance), status of various protective instruments like isolators, circuit breakers; temperatures of various instruments, working tap of transformers etc.

The relay room is separate from the control room. All relays used here are numerical and are either from Siemen ”OR ABB”.

The protection system is so fast that it can detect a fault within 30 ms and hence the circuit breaker can be operated within as less as 80 ms. For 400 kV side C.B.

TRANSMISSION POLE

REFERENCES

C.L.Wadhwa “Electrical Power System”, 6th Edition.   Wikipedia. Power Station Manual Of UPPCL, Mottiram Adda, Gorakhpur.

THANK YOU