UTTAR PRADESH POWER C0RPORATION LTD.
KAMAL MITTALKAMAL MITTALEN- 4EN- 4thth YEAR YEAR
DESCRIPTION OF 220KV SUBSTATION, MURADNAGAR
The 220KV power substation has the capacity-(2*160MVA+1*100MVA). It receives three 220kv lines from Sikandrabad, Loni and Dadri and two 400kv lines from Modipuram (circuit 1) and a newly installed circuit 2. It steps down this supply to 132kv, 66kv, 33kv and 11kv. 132kv line gives supply to Lalkuan, Morta, Newari, Modisteel, Hapur and Dasna, 33kv line to Rawli, Noorpur, Goelispat, and 11kv to New substation.
SINGLE LINE DIAGRAM 220KV SUBSTATION MURADNAGAR
TRANSFORMERSAlso known as the heart of substations. These are used to reduce the voltages at appropriate levels
CURRENT VOLTAGE TRANSFORMERSIt is a used in power systems to step downextra high voltage signals and provide a low voltage signal, for measurement or to operate a protective relay
WAVETRAPTraps the high frequency signals
ISOLATORSUsed for maintenance of
the circuit in no load condition
CIRCUIT BREAKER used to protect the
eqiupment by opening the circuit for over
current and over voltages
LIGHTINING ARRESTER
Used for protecting the equipment from surge
voltages
MAIN EQUIPMENTS AT MURADNAGAR SUBSTATION 220KV
LIGHTNING ARRESTER
DEFINATION A lightning arrester is a device used on electrical power systems to protect the insulation on the system from the damaging effect of lightning.
L.A CIRCUIT DIAGRAM
1.Rod arrester2.Horn gap arrester3.Multi gap arrester4.Expulsion type lightning arrester5.Valve type lightning arrester6. Silicon Carbide Arrestors7. Metal Oxide ArrestorsAt MURAD NAGAR substation we use ZINC OXIDE ARRESTOR GAPLESS
ALSO KNOWN AS SURGE ARRESTERUSED IN THE POWER SYSTEMS TO PROTECT FROM LIGHTNINGWHEN SUURGE TRAVELS ALONG THE LINE , THE ARRESTOR DIVERTS IT TO THE EARTH
CURRENT VOLTAGE TRANSFORMER
A capacitor voltage transformer (CVT), or capacitance coupled voltage transformer (CCVT) is a transformer used in power systems to step down extra high voltage signals and provide a low voltage signal, for measurement or to operate a protective relay.In its most basic form the device consists of three parts: two capacitors across which the transmission line signal is split, an inductive element to tune the device to the line frequency, and a transformer to isolate and further step down the voltage for the instrumentation or protective relay.
CURRENT VOLTAGE TRANSFORMER
CVTs are typically single-phase devices used for measuring voltages in excess of one hundred kilovolts where the use of wound primary voltage transformers would be uneconomical. In practice, capacitor C1 is often constructed as a stack of smaller capacitors connected in series. This provides a large voltage drop across C1 and a relatively small voltage drop across C2.
WAVE TRAPWAVE TRAP
Reliable & fast communication is necessary for safe efficient & economical power supply . To reduce the power failure in extent & time, to maintain the interconnected grid system in optimum working condition to coordinate the operation of various generating unit communication network is indispensable for state electricity board.
CURRENT VOLTAGE TRANSFORMER
Wave trap is an instrument using for trapping of
the wave. The function of this trap is that it traps
the unwanted waves. Its function is of trapping
wave. Its shape is like a drum. It is connected to
the main incoming feeder so that it can trap the
waves which may be dangerous to the instruments
here in the substation. Low pass filter when power
frequency currents are passed to switch yard and
high frequency signals are blocked.
It is used for communication purpose.
ISOLATORISOLATOR
Isolator
Used to ensure that an electrical circuit is completely de-energised 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. High-voltage isolation switches are used in electrical substations to allow isolation of apparatus such as circuit breakers, transformers, and transmission lines, for maintenance. The disconnector is usually not intended for normal control of the circuit, but only for safety isolation. Disconnector can be operated either manually or automatically (motorized disconnector)
STEPS OF OPERATION OF STEPS OF OPERATION OF
ISOLATORISOLATOR SEQUENCE OF STEPS FOR ATTENDING
MAINTENANCE:
1.Open CB on no load or full load
2.Open the isolator on no load
3.Close the earth switch
SEQUENCE OF STEPS FOR KEPT IN SERVICE
1.Open the earth switch
2.Close the isolator
3.Close the CB
CIRCUIT BREAKERCIRCUIT BREAKER
A circuit breaker is 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 so designed that it can be
operated manually (or by remote control)
under normal conditions and automatically
under fault condition. Whenever a fault
occurs trip coil gets energized, the moving
contacts are pulled by some mechanism &
therefore the circuit is opened or circuit
breaks.
CIRCUIT BREAKERCIRCUIT BREAKER1. Actuator mechanism - forces the
contacts together or apart
2. Contacts - Allow current when touching and break the current when moved apart
3. Terminals
4. Bimetallic strip.
5. Calibration screw - allows the manufacturer to precisely adjust the trip current of the device after assembly.
6. Solenoid
7. Arc divider/extinguisher
Sulpar hexafluoride circuit breaker (SF6) Sulphar hexa fluoride (SF6) gas is used as the arc quenching medium . The SF6 is an electronegative gas and has a strong tendency to absorb free electrons. Circuit breakers have been developed for voltage 115KV to 230KV , power rating10 MVA
Vacuum circuit breakers Vacuum circuit breakers are circuit breakers which are used to protect medium and high voltage circuits from dangerous electrical situations
Air-blast circuit breakerFast operations ,suitability for repeated operation , auto reclosure , unit type multi break constructions ,simple assembly , modest maintenance are some of the main features of air blast circuit breakers. A compressors plant necessary to maintain high air pressure in the air receiver.
Oil circuit breakerA high-voltage circuit
breaker in which the arc is drawn in oil to dissipate the heat and extinguish the arc; the intense heat of the arc decomposes the oil .
DIFFERENT CIRCUIT BREAKERS
CIRCUIT BREAKERCIRCUIT BREAKER2OIL CIRCUIT BREAKERS2OIL CIRCUIT BREAKERS
Oil circuit breaker
Air-blast circuit breaker
Sulpar hexafluoride circuit breaker (SF6)Vacuum circuit breakers
TRANSFORMERSTRANSFORMERS
POWER TRANSFORMERSTransformer is a static machine, which transforms the potential of alternating current at same frequency. It means the transformer transforms the low voltage into high voltage & high voltage to low voltage at same frequency. It works on the principle of mutual inductance.When the energy is transformed to a higher voltage, the transformer is called step up transformer and then it is transmitted at lower voltage it is called step down transformer.There are 3 transformers in the substation:160MVA, 220/132 KV (2nos.)100 MVA TRANSFORMER(1)
Power Transformer feedingPower Transformer feeding160 MVA transformers are manufactured by ADITYA and by TRM. These are the power transformers and , there efficiency is high. Primary side is star connected while secondary is delta connected. There are seventeen tapping in it. Every transformer has OLTC to change the tap for controlling voltage.
TYPES OF COOLING:AIR NATURAL COOLINGAIR BLAST COOLINGOIL NATURAL COOLINGOIL BLAST COOLING etc.
SOME IMPORTANT COMPONENTSSOME IMPORTANT COMPONENTS
Earth switch: It is a switch normally kept open and connected between earth and conductor. If the switch is closed it discharges the electric charge to ground, available on the uncharged line.
Bus-bar: When number of lines operating at the same voltage levels needs to be connected electrically, bus-bars are used. Bus-bars are conductors made of copper or aluminum, with very low impedance and high current carrying capacity.
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.
Insulators They support the conductor (or bus bar) and confine the current to the conductor. The most commonly used material for the manufactures of insulators is porcelain. There are several type of insulator (i.e. pine type, suspension type , strain type ,shackle types etc.) and there used in Sub-Station will depend upon the service requirementPotential transformers (PT): The lines in substations operate at high voltages. The measuring instruments are designed for low value of voltages. Potential transformers are connected in lines to supply measuring instruments and protective relays. These transformers make the low voltage instruments suitable for measurement of high voltages.
THANKS