35kV Oil Transformer Double-Winding On-Load Tap Chaging Transformer 800-31500kVA for Substation

Our 35kV oil-immersed power transformer is designed for reliable power distribution in medium-sized substations and industrial applications. Engineered for continuous operation under demanding conditions, this on-load tap-changing transformer ensures stable voltage regulation without interrupting the power supply. Compliant with GB1094.1-5 international standards, it delivers high efficiency, low noise, and long service life.

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35kV Oil Transformer Double-Winding On-Load Tap Chaging Transformer 800-31500kVA for Substation

Electrical Products

Features
Technical Specifications

Key Structural Features of 35kV Oil-Immersed Power Transformer

1.Core Design
Material: High-permeability grain-oriented cold-rolled silicon steel.

Configuration: Stepped core with multi-stage circular cross-section and full mitered lap joints, minimizing no-load losses and excitation current.

2. Windings & Voltage Regulation
Winding Type: Concentric (cylindrical) windings for enhanced mechanical strength and short-circuit withstand capability.

Tap Changer: Equipped with an on-load tap-changer (OLTC) mounted on the tank cover. Allows voltage adjustment under load without cutting off the power supply. Manual and automatic operation options are available.

3. Safety & Protection
Gas Relay (Buchholz Relay): Provides protection against internal faults.

Pressure Relief Device: Prevents excessive internal pressure buildup.

Oil Conservator: Maintains oil volume with a magnetic oil level gauge.

Air-Drying Breather (Silica Gel): Prevents moisture ingress.

4. Temperature Monitoring
Oil Temperature Measurement: Includes a thermometer pocket for glass thermometers and a dial-type thermometer (for units ≥1000 kVA) for remote monitoring.

5. Tank & Accessories
Oil Sampling Valve: Convenient for maintenance.

Drain Valve: Facilitates easy oil change.

Base Design: Compatible with GB6451-2008 mounting dimensions (wheels optional).

Main Technical Parameters

Rated Capacity (kVA)	Voltage Combination			Connection Symbol	Loss (kW)		No‑Load Current (%)	Short‑Circuit Impedance (%)	Weight(kg)
	Voltage Combination				S11 type				Weight(kg)
	High Voltage (kV)	HV Tapping Range	Low Voltage (kV)		Losses (Load)	Losses (No-load)			Weight (Oil)	Weight (Total)
800	38.5 35	±3×2.5% ±4×2.5%	3.15 6.3 10.5 10.0 11.0	Yd11	9.88	1.08	1.3	6.5	1010	3360
1000					12.16	1.28	1.2		1080	3800
1250					14.725	1.52	1.1		1170	4250
1600					17.58	1.84	1.1		1400	5010
2000					19.24	2.30	0.8		1590	5820
2500					20.64	2.72	0.8		1700	6350
3150					24.71	3.23	0.72	7	1950	7950
4000					29.16	3.87	0.72		2165	9065
5000					34.20	4.64	0.68		2250	9810
6300					36.77	5.63	0.68	7.5	2610	12010
8000				YNd11	40.61	7.87	0.6		2890	14790
10000					48.05	9.28	0.6		3830	18750
12500					56.86	10.944	0.56	8	4270	23530
16000					70.32	13.17	0.54		6200	25600
20000					82.78	15.57	0.54		7500	32670
25000					101.65	18.96	0.5		7800	42020
31500					119.70	22.00	0.4		8960	44330

Outline and Mounting Dimensions

Rated Capacity (kVA)	Outline and Mounting Dimensions (mm)
Rated Capacity (kVA)	L	W	H	C1	C2
800	2740	970	2120	820	820
1000	3000	990	2170	820	820
1250	3070	1020	2190	820	820
1600	3150	1060	2250	820	820
2000	2700	1100	2300	1070	1070
2500	3120	2300	2365	1070	1070
3150	3220	2350	2410	1070	1070
4000	3300	2560	2490	1070	1070
5000	3350	2750	2550	1070	1070
6300	3580	2800	3080	1475	1475
8000	3790	2610	3210	1475	1475
10000	3870	3220	3400	1475	1475
12500	3990	3260	3540	1475	1475
16000	4370	3480	3680	1475	1475
20000	4850	3050	3970	1475	1475
25000	5470	4000	4010	1475	1475
31500	5900	4450	4100	1475	1475