2. INTRODUCTION
Switchyard are the area of power point where transmission line connected with
distribution feeders and interconnected with other yard and Generating power
plant.
Switchyard consist of following Equipment
1.Circuit Breaker
2.Current transformer
3. Capacitive voltage transformer
4. Wave Trap
5.Isolators
6.Lightining Arrestor
7.Interconnected transformer
3. INTRODUCTION
8. Reactors
9. ACDB
10.DCDB
11.B.MK
12.Local control panels
13.Control and relay panels
There are different types of switchyard based on insulation
1. A.I.S
2. G.I.S
And based on rating of voltage
1.765/400 KV
2.400/220 KV
3.220/132 KV
4.132/33/11 KV
4. Erection or Installation
For Erection or Installation of any structure and Equipment need following drawing
1. Electrical layout
2. Erection key Diagram
3. Single line diagram
4. BOQ
5. Typical drawing
For switchyard erection there are sequence of work are below
1. Tower erection
2. Stringing
3. Earthing
4. Equipment erection/ Al tube erection/ Jumpering
5. Electrical panel erection
6. Cable laying & Termination
5. Testing
Safety
All measures and precautions should be undertaken to prevent occurrence of unsafe acts.
All the personal involved should be thoroughly apprised about the safe procedures to be
adopted while performing various activities including carried out test in the switchyard.
1. TEST Applicable for C.T
A. Current transformer
. Polarity test
. Magentization charactaracterics of CT
.I.R
.DGA CT oil
.Tan delta
.Ratio test
6. TESTING
Test applicable for Circuit Breaker
.Dew point of SF6
.Measurement of Circuit breaker operating timing including P.I.R TIMING
.Operational lockout
Measurement of static contact resistance
.Pole discrepancy relay
Checking of N2 PRIMARY PRESSURE
.Grading capacitor tan delta
9. Testing
Test applicable for Lightining arrestor
.Third harmonic resistance current
.IR Of each stack
.Checking of L.A counter
10. Testing
Test applicable for ICT/REACTORS
Main body inspection ensure filled with N2 OR DRY AIR PRESSURE.
. Oil drum
.I.R
.Vector group test & polarity check
.short circuit impedance check
.magnetic balance test
.Voltage ratio test
.Floating neutral test
.Magnetising current test
.voltage ratio test
11. Testing
.I.R Measurement of bushing C.T
.Continuity test of bushing CT
.Secondary winding resistance of bushing CT
.Polarity test of Bushing CT
.Current ratio test
.Magneting curve performance
.C.R.M
.TAN DELTA & Capactance measurement of bushing
.Protection and alarm test
.Satability test
.SFRA
.Measurement of winding resistance