POWER HOUSE

Important considerations in design:-

safety of personal equipment.

reliability and security.

possibility to expand.

ease in maintenance.

DESIGN OF POWER HOUSE

COMPONETS OF POWER HOUSE:

SURGE ARRESTORS OR LIGHTARRESTER

CURRENT TRANSFORMER (C T )

CIRCUIT BREAKER

POTENTIAL TRANSFORMER (P T )

POWER TRANSFORMER

RELAY

WAVE TRAP

BUS BAR

ISOLATER

SURGE ARRESTORS OR LIGHTARRESTER:NING

Surge Arresters or Lightning Arresters

discharge the over voltage surges to

earth and protect the equipment

insulation from switching surges and

lightning surges.

Surge arresters are generally connected

between phase conductor and ground.

In a Substation surge arrester is located

at the starting of the substation as seen

from incoming transmission lines and is

the first equipment of the substation.

Surge arresters are also provided near the

transformer terminals phase to ground.

CURRENT TRANSFORMER (C T )

Current transformers (CT): The

lines in substations carry currents in

the order of thousands of amperes.

The measuring instruments are

designed for low value of currents

Current transformers are connected in

lines to supply measuring instruments

and protective relays. For example a

100/1A CT is connected in a line

carrying 100A, and then the

secondary current of CT is 1A.

Current transformers are used for

Stepping down current for

measurement, protection and control.

POTENTIAL TRANSFORMER (P T )Potential transformers (PT): The lines

insubstations operate at high voltages. Themeasuring instruments are designed for low value of voltages. Potential transformersare connected in lines to supply measuring instruments and protective relays. Thesetransformers make the low voltage instruments suitable for measurement of highvoltages. For example a 220 kV/110V PT is connected to a power line and the line voltageis 220 kV then the secondary voltage will be 110V.

Voltage transformers are used to step down the voltage for measurement, protectionand control. Voltage transformers are of two types.1 Electromagnetic type2 Capacitive VT located on the feeder side of the Circuit Breaker.

Potential transformers

POWER TRANSFORMER

Power Transformers are used to step up or step – down a.c. voltages and to transfer electrical power from one voltage level to another. Tap changers are used for voltage control.

Transformers range in size from thumbnail-sized units hidden in microphones to units weighing hundreds of tons used in the power grid.

A wide range of transformer designs are used in electronic and electric power applications.

TRANSFORMER

PROTECTION OF POWER TRANSFORMER USING 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

THANK YOU…..