TRANSFORMER VECTOR GROUP

The vector group test is importent test in the transformer testing

The Test procedure

1. Connect the HV side "R" phase with LV side " R" phase. ( No need for Auto transformer )

2. Apply the 3 Phase voltage (380v) on HV side.

3. Measure the voltages in various combination on both side of the transformer ( HV- LV ).

4. For each vector group need diffrent type of voltage combination to conform the vector group ( refer drawings ).

For more information

http://electricalnotes.wordpress.com/2012/05/23/vector-group-of-transformer/

Jubail -2 Sub-3 Energization

This station successfully energization without any small problem 25 & 26 on June 2012.
Really i got good confident on the work and well experience.
We got good team during commissioning and its lead us to success.
Note:-
The total bay portion of Line and transformer feeders are protected by there own relays
The spare feeders are protected by only busbar protection and it will cover up to CB line side CT.
During first time charging we need to protect the spare feeders up to Air bushing.
Generally two methods are following to protect the spare feeders.
1. If short the CB line side Busbar CT then busbar protection will cover upto Air bushing.
2. Change the other end (Existing end ) protection relay Zone 2,3 time settings to zero and it will cover upto New station spare feeder air bushing.

BUSBAR & BF PROTECTION TESTING

The testings in Busbar protection low impedance relays DOWNLOAD

The testings in Beaker Failure protection relays DOWNLOAD

BREAKERS RATINGS

230kV GIS BREAKER

1. Nominal system voltage = 230kV

2. Maximum system voltage = 242 kV

3. Maximum system voltage = 253 kV for 30 mim

4. Rated continuous current = 3150 A for Bus couppler

5.Rated continuous current = 2500 A for I/C & O/G feeders

6. Rated system short circuit interrupting current of the CB = 63kA

34.5kV BREAKER

1. Nominal system voltage = 34.5 kV

2. Maximum system voltage = 36.2 kV

3. Maximum system voltage = 38 kV for 30 mim

4. Rated continuous current = 2500 A for Bus Tie & Incomer

5.Rated continuous current = 1250 A for O/G feeders

6. Rated system short circuit interrupting current of the CB = 31.5 kA

SITE TESTING OF LINE DIFFERENTIAL RELAY

1.Analog input Measurements 

Inject the rated secondary CT & VT values and check the primary and secondary values and power values  in the relay.

2.Input and Out put card checks

Give the digital input commands check the response in the relay
Check the all output contacts of the relay

3.  LED status

Check the all LED status as per configuration

4. Secondary injection tests 

4.1 . Check all settings are applied for function
4.2.  Zone reach measurements
4.3. Zone timings
4.4. Phase selection function
4.5. Power swing
4.7. Switch On to faults
4.8. Scheme communication Logic
a. Permissive under reach
b. Permissive over reach
c. Blocking scheme
d. Direct inter trip scheme
e. DIST WEI ECHO
g. Current reversal Logic

5. Over current & Earth fault function 

6.DEF COMMUNICATION SCHEME

6.1. Permissive over reach scheme
6.2. Blocking scheme
6.3. DEF WEI ECHO
6.4. DIST WEI TRIP
6.5. Current reversal logic

7. Fault locator function

8. Differential Function

8.1. Communication failure checks
8.2. Pickup/ Drop off Id min
8.3. Time measurement for Id min &  Id min High
8.4. Alarm checks
8.5. Bias Characteristic Testing
8.6. Harmonics Restraint Checks

9. Auto Re-close Checks