500kV 550kV Single-phase Oil-Immersed Air-Cooled Autotransformer with Three Windings and No Excitation

Name: 500kV 550kV Single-phase Oil-Immersed Air-Cooled Autotransformer with Three Windings and No Excitation
Brand: Rockwill Electric GROUP Co., Ltd
SKU: 2669
Price: 1.99 USD
Availability: InStock

Rockwill Electric GROUP Co., Ltd

16yrs 700++ staff 108000m²+m² US$150000000+ China

Rockwill Electric GROUP Co., Ltd

16yrs 700++ staff 108000m²+m² US$150000000+ China

Attributes

Description

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Key attributes

Brand	ROCKWILL
Model NO.	500kV 550kV Single-phase Oil-Immersed Air-Cooled Autotransformer with Three Windings and No Excitation
Rated voltage	550kV
Rated frequency	50/60Hz
Series	ODFS

Product descriptions from the supplier

Description

Description：

The 500kV/550kV Single-Phase Oil-Immersed Air-Cooled Autotransformer with Three Windings and No Excitation is engineered for ultra-high voltage transmission networks requiring exceptional reliability and efficiency. Its oil-immersed air-cooled (ONAN) design ensures effective heat dissipation under continuous operation, while the three-winding configuration provides flexible power allocation and system interconnection capabilities. The no-excitation voltage regulation mechanism eliminates the complexity of on-load tap changers, reducing maintenance needs and enhancing operational stability. Ideal for core grid substations, this transformer delivers robust performance in demanding environments with minimal lifecycle costs.

Product Characteristics:

Rational Structural Design：Leveraging advanced modern calculation technologies, the transformer’s structure is optimized through in-depth analysis of its electrical, magnetic, mechanical, and thermal properties. This ensures structural integrity and performance synergy across all operational conditions.
Advanced Performance Indicators：Compliant with international IEC standards, the product can also be tailor-made to meet specific customer requirements. Its partial discharge (PD) level is significantly lower than the limit specified in IEC 60076-3, delivering exceptional electrical performance and operational stability.
High Operational Reliability：Reliability is guaranteed by comprehensive analysis of electrical, magnetic, mechanical, and thermal characteristics. Combined with a scientific insulation structure, optimized ampere-turn distribution, and efficient cooling system, it boasts strong resistance to overvoltage and short-circuit currents, eliminating the risk of local overheating during long-term operation.
Premium Configured Accessories：Equipped with high-quality accessories, the transformer offers superior user experience. It features an aesthetically pleasing appearance, reliable leak-proof design, and supports maintenance without tank disassembly—achieving a near maintenance-free operation mode that reduces operational costs and workload.

Technical Parameters:

Among these, some autotransformers cover non-standard voltage levels including 121kV, 132kV, 138kV, 200kV, 225kV, 230kV, 245kV, 275kV, 330kV, 345kV, 400kV and 756kV, We also provide customization services.

500kV 100MVA~484MVA Single-phase, Double-winding Power Transformer with Off-circuit Tap-changer

Rated capacity (kVA)	Voltage combination and tapping range		Vector group	Energy consumption class Ⅰ		Energy consumption class Ⅱ		Energy consumption class Ⅲ		Short-circuit impedance (%)
Rated capacity (kVA)	HV tapping range (%)	LV (kV)	Vector group	No-load loss (kW)	On-load loss (kW)	No-load loss (kW)	On-load loss (kW)	No-load loss (kW)	On-load loss (kW)	Short-circuit impedance (%)
100	500/√3 525/√3 535/√3 550/√3	13.8;15.75	Ii0	34	203	40	203	49	214	14
120		15.75;18;20		39	234	46	234	56	247
200		15.75;18;20;24		63	342	74	342	91	361
223		18		68	371	81	371	99	391
240		18;20;24		72	392	85	392	105	413
260		18;20		77	414	91	414	112	437
380		24;27		102	549	121	549	149	580	16 or 18
400				106	570	125	570	154	601
410				108	581	128	581	158	613
484				123	657	145	657	178	694

Note: Transformers with various special parameters and performance can be manufactured according to customer requirements.

500kV 120MVA~1170MVA Three-phase, Double-winding Power Transformer with Off-circuit Tap-changer

Rated capacity (kVA)	Voltage combination and tapping range		Vector group	Energy consumption class Ⅰ		Energy consumption class Ⅱ		Energy consumption class Ⅲ		Short-circuit impedance (%)
Rated capacity (kVA)	HV tapping range(%)	LV (kV)	Vector group	No-load loss(kW)	On-load loss(kW)	No-load loss(kW)	On-load loss(kW)	No-load loss(kW)	On-load loss(kW)	Short-circuit impedance (%)
120	500 525 550	13.8；15.75	YND11	41	356	49	356	60	375	14
160				50	441	59	441	72	466
240				69	599	81	599	100	632
300		13.8；15.75；18		80	707	94	707	116	746
370		15.75；18；20		94	810	111	810	136	855
400		18；20；24		96	855	114	855	140	903
420		15.75；18；20		102	860	120	860	148	907	14 or 16
480		15.75；18；20		110	954	130	954	160	1007
600		15.75；18；20；24		143	1202	169	1202	208	1268
720		18；20；24		168	1382	198	1382	244	1458
750		20；22		173	1422	205	1422	252	1501	16 or 18
780		22		176	1467	208	1467	256	1549
860		22		190	1575	224	1575	276	1663
1140		27		237	1949	280	1949	344	2057
1170		27		242	1980	286	1980	352	2090

Note: Transformers with various special parameters and performance can be manufactured according to customer requirements.

500kV 120MVA~1170MVA Three-phase, Double-winding Power Transformer with Off-circuit Tap-changer

Rated capacity (kVA)	Voltage combination and tapping range			Vector group	Energy consumption class Ⅰ		Energy consumption class Ⅱ		Energy consumption class Ⅲ		Short-circuit impedance (%)
Rated capacity (kVA)	HV (kV)	MV tapping range (kV)	LV (kV)	Vector group	No-load loss (kW)	On-load loss (kW)	No-load loss (kW)	On-load loss (kW)	No-load loss (kW)	On-load loss (kW)	Short-circuit impedance (%)
120	600/ √3 625/ √3 650/ √3	230/√3 230/√3 ±2×2.5% 242/√3 ±2×2.5%	35 36 37 38.5 63 66	Iaoi0	28	207	33	207	40	219	HV-MV 12 HV-LV 34 ~ 38 MV-LV 20 ~ 22
167					33	248	39	248	48	261
250					47	333	55	333	68	352
334					58	428	68	428	84	451
400					66	491	78	491	96	518
120					28	221	33	221	40	233	HV-MV12 HV-LV 42 ~ 46 MV-LV 28 ~ 30
167					33	261	39	261	48	276
250					47	356	55	356	68	375
334					58	459	68	459	84	485
400					66	522	78	522	96	551
120					28	221	33	221	40	233	HV-MV 14 ~ 15 HV-LV 42 ~ 46 MV-LV 28 ~ 30
167					33	261	39	261	48	276
250					47	356	55	356	68	375
334					58	459	68	459	84	485
400					66	522	78	522	96	551

Note: Transformers with various special parameters and performance can be manufactured according to customer requirements.

Normal Service Conditions

(1) Altitude: ≤1000m;

(2) Ambient temperature:Maximum temperature: +40℃;Maximum monthly average temperature: +30℃;Maximum yearly average temperature: +20℃;Minimum temperature: -25℃.

(3) Power supply: approximate sinusoidal wave, three-phase symmetrical approximately

(4) Installation site: indoor or outdoor, without the obvious contamination.Note: The transformer used in special conditions should be specified when ordered.

FAQ

Q: For 500kV/550kV no-excitation autotransformers, how to balance operational stability and maintenance convenience?

Its design achieves a perfect balance through two aspects: On the stability side, the no-excitation voltage regulation structure simplifies internal components, reducing failure points; the scientific insulation design and strict compliance with IEC standards further enhance operational reliability. On the maintenance side, the oil-immersed air-cooled system adopts mature leak-proof technology, and the accessories support maintenance without tank disassembly. This combination ensures long-term stable operation while lowering daily maintenance costs and workload for users.

Q: What makes the 500kV/550kV single-phase oil-immersed air-cooled autotransformer suitable for large-scale power grids?

As a key UHV equipment, it integrates three-core advantages tailored for large grids: First, the oil-immersed air-cooled design ensures efficient heat dissipation, adapting to long-term high-load operation. Second, the three-winding structure realizes flexible voltage conversion between 500kV/550kV and lower levels, optimizing power transmission efficiency. Third, it has strong overvoltage and short-circuit resistance, maintaining grid stability even in complex working conditions. These features make it a core component for long-distance and large-capacity power transmission.

Know your supplier

ROCKWILL

Rockwill Electric GROUP Co., Ltd
16yrs 700++ staff 108000m²+m² US$150000000+ China

Rockwill Electric GROUP Co., Ltd

16yrs 700++ staff 108000m²+m² US$150000000+ China

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On-time delivery rate

Response time

100.0%

≤4h

Company overview

Workplace: 108000m²m² Total staff: 700+ Highest Annual Export(usD): 150000000

Workplace: 108000m²m²
Total staff: 700+
Highest Annual Export(usD): 150000000

Services

Business Type: Design/Manufacture/Sales

Main Categories: High Voltage Electrical Apparatus/Electric transformer

Whole life care manager

Whole-life care management services for equipment procurement, use, maintenance, and after-sales, ensuring safe operation of electrical equipment, continuous control, and worry-free electricity consumption.

The equipment supplier has passed platform qualification certification and technical evaluation, ensuring compliance, professionalism, and reliability from the source.

Negotiable

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Model

ODFS-334000/550

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Whole life care manager

The equipment supplier has passed platform qualification certification and technical evaluation, ensuring compliance, professionalism, and reliability from the source.