110kV Oil-immersed Power Transformer

Economic or deluxe solution optional Better cost performance IEC Standards Criteria New factory for better price NVTC/ OLTC

REFERENCES

ISO 1461: Hot dip galvanized coatings on fabricated iron and steel articles – Specifications and test methods.

IEC 60076: Power transformers.

IEC 60044: Instrument transformers.

IEC 60296: Specification for unused mineral insulating oil for transformers and switchgear.

IEC 60354: Loading guide for oil – immersed power transformers.

IEC 60214: Tap-changers - Part 1: Performance requirements and test methods, Part 2: Application guide.

IEC 60512: Connectors for electronic equipment.

Performance

110kV Two-Winding Power Transformer With NVTC/OLTC
Rated Capacity  (kVA)	Rated Voltage (kV)			Vector  Group	Losses (W)		Impedance  Voltage  (%)
	HV	Tapping  Range	LV		No load	On load
6300	110 121	±2×2.5%	6.3 6.6 10.5 11	YNd11	8000	36900	10.5
8000					9600	45000
10000					11200	53100
12500					13200	63000
16000					16000	77400
20000					19000	93600
25000					22400	110700
31500					26700	133200
40000					31800	156600
50000					37600	194400
63000					44600	234000

110kV Three-Winding Power Transformer With   NVTC/OLTC
Rated Capacity  (kVA)	Rated Voltage (kV)			Vector  Group	Losses (W)		Impedance Voltage (%)
	HV	Tapping  Range	LV		No load	On load	Step Up	Step Down
6300	110 ±2×2.5%   121 ±2×2.5%	35 38.5 ±2×2.5%	6.3 6.6 10.5 11	YNyn0d11	9600	47700	HV-MV 17-18 HV-LV 10.5 MV-LV 6.5	HV-MV 10.5 HV-LV 17-18 MV-LV 6.5
8000					11500	56700
10000					13600	66600
12500					16000	78300
16000					19300	95400
20000					22800	112500
25000					27000	133200
31500					32000	157500
40000					38200	189000
50000					45200	225000
63000					53600	270000

INSULATION LEVELS

Nominal system voltage (kV,   rms)	Highest system voltage (kV,   rms)	Lightning Impulse withstand voltage, dry (kV,   peak)	Power frequency withstand voltage, wet (kV,   rms)
33	36	200	95
132	145	650/750 (internal/external)	275/325 (internal/external)

AUXILIARY SUPPLIES

Equipment generally rated for the following auxiliary power supplies:

(a)          Cooler control circuits:          220V, 240 V, single phase, 50Hz

(b)         Tap changer control:              220V, 240 V, single phase, 50Hz

(c)          Cooling fan motors:               380V, 415 V, three phase, 50Hz

(d)         Tap changer motor:               380V, 415 V, three phase, 50Hz

 

 ROUTINE TEST to IEC 60076 (to be done during acceptance testing at factory)

 

 

• Measurement of winding resistance

• Ratio test

• Vector group

• Separate source voltage withstand test

• Induced over-voltage

• Insulation resistance

• Oil leakage test on fully assembled transformer for 12 hours

• Measurement of impedance voltage

• Magnetic balance

• Measurement of no-load loss and current

• Measurement of load loss (at normal & extreme taps)

• Tests on on-load tap-changer

• Tests on on-load tap-changer remote control panel

• Efficiency at 50%, 75%, 100% loading at unity p.f and rated terminal voltage (Corrected to 75C)

• Lightning impulse withstand test

Type Tests to IEC 60076 (to be done during acceptance testing at factory)

• Temperature rise test – To be performed on one unit during acceptance testing.

Lightning Impulse Withstand Test is already listed under Routine Tests as per IEC 60076.

Test Facility

Installation

110kV Oil-immersed Power Transformer