HENGFENGYOU TRANSFORMER|ANSI/IEEE STANDARD TRANSFORMER
HENGFENGYOU TRANSFORMER|ANSI/IEEE STANDARD TRANSFORMER
The 330kV three‑phase oil‑immersed power transformer is key ultra‑high‑voltage core equipment for national provincial backbone transmission grids, large-scale energy base delivery, cross-regional power transmission, heavy industrial power supply and large power plant main step-up scenarios. It is specially developed for long-distance, large-capacity cross-regional power transmission and grid voltage stabilization, with a maximum design capacity of 630MVA. Benefiting from stable and reliable performance, it has been widely deployed in major power grid projects and industrial energy projects around the world. With 30 years of ultra-high voltage transformer R&D and manufacturing experience, Hengfengyou Electric provides one-stop customized 330kV power transformer solutions that fully comply with international and national authoritative standards, featuring ultra-low loss, extreme environmental adaptability, super long service life and intelligent operation compatibility.
Mainstream Type: Three‑phase two‑winding / three‑winding / auto-transformer oil‑immersed power transformer
Capacity Range: 120MVA – 630MVA
Cooling Mode: OFAF, ODAF, ONAN/ONAF optional, matching full-load and overload operation requirements
Core Applications: Provincial backbone grid substations, cross-regional power transmission hubs, large wind/solar centralized delivery bases, heavy industrial clusters (metallurgy, chemical, mining), urban core bulk power supply substations, large thermal power and new energy power plant main step-up stations
Compliance Standards: GB 1094 series, GB 20052-2024 new energy efficiency standard, IEC60076, GOST, EN, NF, ANSI/IEEE, support personalized customization according to client national standards and project specifications
Authoritative Certifications: ISO quality system certification, CE, IEC product certification, SABS, COC, CSA, UL, meeting global project bidding and access requirements
Energy Efficiency & Loss Performance: Overall efficiency ≥99.4%, fully compliant with EU 2015/2014/548/EC Ecodesign Tier 2 energy-saving standards and national secondary energy efficiency requirements. Adopts optimized electromagnetic structure design and high-performance magnetic materials, with ultra-low no-load loss and load loss, realizing long-term low-carbon, energy-saving and economic operation of the power grid.
Two‑Winding Transformer: 330kV + single medium/low voltage winding; simple structure, low failure rate, cost-effective, suitable for single-voltage large-capacity power transmission scenarios of power plants and single-load industrial bases
Three‑Winding Transformer: 330kV + two medium/low voltage windings; supports multi-voltage hierarchical power supply, improves grid power supply flexibility and reliability, applicable to multi-load composite substations and regional power distribution hubs
Auto‑Transformer: Optimized structure, small size and light weight, low operation loss, high transmission efficiency, specially designed for 330kV regional backbone grid interconnection and cross-voltage level power transmission projects
MR (Germany): Industry-leading ultra-high reliability, mechanical service life exceeding 200,000 switching operations, stable performance under long-term heavy load and frequent voltage regulation, preferred for national backbone grid key projects and harsh working condition scenarios
ABB: Balanced comprehensive performance, perfect global after-sales service network, strong compatibility with smart grid systems, supports remote intelligent regulation, suitable for international large-scale EPC projects and urban core grid projects
Huaming (China): High cost performance, fast on-site after-sales response, stable mechanical performance with service life of about 100,000 operations, suitable for cost-sensitive heavy industrial power supply projects and conventional regional grid substations
Selection Principle: Imported OLTC brands are recommended for 330kV backbone grid, cross-regional transmission and extreme working condition projects; domestic high-quality brands are adopted for industrial supporting and cost-controlled conventional projects to balance performance and economy.
Adopts enhanced UHV external insulation design and heavy-duty anti-corrosion coating process, which can stably adapt to high altitude (above 3000m), heavy industrial pollution, coastal salt fog, high temperature and low temperature extreme environments. Optimized low-noise structural design and fire-resistant and explosion-proof configuration, meeting the operation requirements of urban built-in, indoor and underground 330kV substations. It has strong load fluctuation resistance, can cope with the unstable power output of large-scale centralized photovoltaic and wind power bases, and maintains stable operating parameters under long-term fluctuating load conditions.
Matching GIS/HGIS fully enclosed switchgear is adopted to realize compact station layout, effectively reduce floor area, and improve overall operation safety and anti-interference ability. The main equipment is connected through high-reliability gas-oil bushing, GIB closed busbar or UHV power cable. The whole system strictly complies with power grid N‑1 safety operation criterion, supporting single-unit independent operation, multi-unit parallel operation and regional grid interconnection operation, ensuring continuous and stable power supply of the system.
Lifting & Placement: Adopt professional large-scale qualified cranes for heavy-duty precision hoisting and positioning, strictly control horizontal deviation and installation accuracy to avoid equipment stress deformation.
Accessory Installation: Complete the standardized installation and debugging of radiators, 330kV ultra-high voltage bushings, oil conservators, forced cooling systems, on-load tap changers and surge arresters to ensure the tightness and firmness of all connecting parts.
Vacuum Oil Filling & Hot Oil Circulation: Implement strict vacuum degassing and constant-temperature hot oil circulation process, thoroughly eliminate internal moisture and residual gas, guarantee the insulation performance of transformer oil and internal insulation structure.
Standing & Venting: After oil filling, the equipment stands for no less than 96 hours, with repeated degassing and multi-index inspection to ensure no hidden danger of internal air bubbles.
Grounding Construction: Adopt integrated reliable grounding for neutral point, tank body and arrester, with grounding resistance strictly controlled ≤1Ω, meeting UHV equipment safety operation standards.
Equipped with high-performance zinc oxide lightning arresters on the high-voltage side to resist lightning surge and overvoltage impact. Matched with 330kV special CSP high-voltage fuse and ultra-high voltage circuit breaker to realize rapid fault isolation. Configure complete main and backup relay protection systems, including differential protection, Buchholz gas protection, overcurrent protection, zero-sequence protection, temperature protection, pressure protection and gas linkage protection, realizing full-range fault monitoring and automatic protection.
Carry out comprehensive factory and on-site pre-commissioning tests in strict accordance with UHV standards, including winding DC resistance test, voltage ratio test, polarity and vector group verification. Complete insulation resistance test, power frequency applied voltage test and induced withstand voltage test to verify internal insulation strength. Conduct high-standard partial discharge test exclusive for 330kV UHV equipment to ensure no partial discharge hidden danger. Perform full-index insulation oil detection including breakdown voltage, moisture content, DGA dissolved gas analysis and furan component analysis. Complete no-load loss and load loss tests to verify ultra-high energy efficiency indicators of the equipment.
Implement integrated linkage test of differential protection and backup protection to ensure accurate and reliable protection action. Complete 5 times no-load impulse closing tests to verify equipment impact resistance and insulation stability. Carry out on-load test operation to calibrate protection polarity and metering accuracy. Conduct full-range linkage debugging of cooling system and OLTC to ensure flexible switching and stable operation of all functional modules.
The equipment adopts long-life optimized design, with standard design life ≥40 years, and the actual service life can reach 50 years under standardized professional maintenance. Equipped with standard online intelligent monitoring system, covering DGA dissolved gas online monitoring, core grounding current monitoring, winding temperature real-time monitoring, partial discharge online detection and bushing operation status monitoring. Support remote data transmission, condition-based maintenance, intelligent early warning and fault alarm functions. Core life extension measures: strictly control winding hot-spot temperature ≤58℃, avoid long-term overload operation, conduct regular oil sampling analysis and standardized preventive maintenance.
Optional FR3 biodegradable vegetable insulating oil, with biodegradability rate over 95%, green and pollution-free, no environmental pollution risk in case of leakage. The equipment adopts a high proportion of recyclable metal and insulating materials, with low carbon emission in the whole life cycle, which is highly compatible with global dual-carbon strategic goals and green power grid construction requirements.
Standard Model: 180 days production and delivery cycle
Emergency Order: Fastest 120 days delivery
Custom Special Model: Special impedance, high altitude anti-icing, heavy corrosion protection, special cooling configuration, 8–12 months delivery cycle
| Item | Core Content | Recommended Scheme/Standard |
|---|---|---|
| Type | 330kV three‑phase oil‑immersed power main transformer | Two/three-winding/auto-transformer, 120MVA–630MVA |
| Standards | Global ultra‑high‑voltage universal standards | GB/IEC/GOST/EN/NF/ANSI/IEEE, compliant with new national energy efficiency standard |
| Efficiency | Ultra‑high efficiency, ultra‑low loss | ≥99.4%, EU Tier 2 & National Grade 2 Energy Efficiency |
| Life | Extra‑long life design | Design life ≥40 years, actual life up to 50 years |
| Eco | Green insulation & low carbon | FR3 vegetable oil optional, biodegradability >95% |
| Cooling | Heavy‑duty cooling modes | OFAF/ODAF/ONAN/ONAF adaptive matching |
| OLTC | Premium brand options | MR, ABB, Huaming (classified selection by scenario) |
| Grounding | Ultra‑high‑voltage safety grounding | Grounding resistance ≤1Ω |
| Delivery | Reliable lead time | Standard 180d, fastest 120d, customized 8–12 months |
Hengfengyou 330kV power main transformer relies on 30 years of UHV equipment manufacturing experience, global top-tier certification system, ultra-high energy efficiency performance and super-long service life design. The product has excellent environmental adaptability and stable operation performance, and is widely applicable to provincial backbone transmission grids, cross-regional power transmission projects, large new energy centralized delivery bases, heavy industrial cluster power supply, urban core substations and large power plant main step-up stations.
Our 330kV transformers have been put into stable operation in more than 60 countries and regions around the world, including Africa, Middle East, Southeast Asia and Central Asia, with zero major failure operation records for many key projects. We adhere to standardized UHV design, modular precision manufacturing, intelligent full-life cycle O&M and one-stop customized service, to provide global customers with safe, reliable, energy-saving and eco-friendly 330kV power transmission and transformation overall solutions.
Q1: What is a 330kV power main transformer?
A: It is the core ultra-high voltage equipment for provincial and cross-regional power transmission grids, mainly used for step-down of 330kV UHV electricity to 110kV/35kV medium and low voltage for regional power distribution, or step-up of medium voltage power generated by power plants and new energy bases to 330kV for long-distance and large-capacity grid-connected power transmission. The capacity range covers 120MVA–630MVA. The core structure consists of high-performance iron core, multi-form winding, sealed fuel tank, heavy-duty cooling system, UHV insulation bushings and complete protection devices.
Q2: What are the main applications of 330kV transformers?
- Provincial backbone grid hubs: Core equipment for connecting cross-regional and provincial transmission networks
- Heavy industrial power supply: Supporting large-scale steel, chemical, mining and metallurgical industrial bases
- Large new energy bases: Main step-up equipment for utility-scale wind farms and photovoltaic power stations
- Urban power supply core: Bulk power supply for super-large and medium-sized urban central substations
- Large power plants: Main step-up station supporting thermal power, hydropower and new energy power plants
Q3: Difference between two‑winding, three‑winding and auto 330kV transformers?
Two‑winding: 330kV + single medium/low voltage winding; simple structure, low cost and high stability, suitable for single-scenario large-capacity power transmission
Three‑winding: 330kV + two medium/low voltage windings; supports dual-channel power supply, flexible grid deployment, high operation reliability, slightly higher cost
Auto-transformer: Optimized integrated structure, small floor area, low operation loss, high transmission efficiency, specially used for grid interconnection and cross-voltage level power transmission projects
Q4: How to choose OLTC brands: MR, ABB, Huaming?
MR: 200,000+ switching life, highest reliability, priority for national backbone grids, cross-regional transmission and extreme working condition projects
ABB: Balanced performance, global service network, smart grid adaptation, suitable for international EPC and urban core grid projects
Huaming: High cost performance and fast after-sales service, ideal for industrial supporting and cost-sensitive conventional substation projects
Selection rule: Imported brands for key backbone grid projects; domestic high-quality brands for conventional industrial and regional grid projects.
Q5: What is the delivery time for 330kV transformers?
- Standard model: 180 days
- Emergency order: Fastest 120 days
- Custom special model (high altitude, anti-corrosion, special impedance, special cooling): 8–12 months
Q6: What is the design life of 330kV transformers?
- Standard design life: ≥40 years (IEC & national UHV standard)
- Actual service life: Up to 50 years with standardized intelligent maintenance
- Core influencing factors: Operating load rate, ambient environment, daily maintenance quality; core control index: winding hot-spot temperature ≤58℃
Q7: What is the warranty term?
- Basic warranty period: 24–36 months after delivery (negotiable per contract)
- Warranty coverage: All manufacturing quality defects
- Independent warranty for consumable parts (OLTC, UHV bushings): 2 years
- Exclusions: Man-made damage, force majeure natural disasters, improper operation and maintenance
Q8: What after‑sales service is provided?
- On-site installation guidance and full-process commissioning technical support
- Professional operator and maintenance personnel technical training
- Regular periodic maintenance, oil testing and preventive performance testing
- Emergency after-sales response: On-site service within 48 hours for global projects
- Upgrading services: Intelligent monitoring transformation, capacity expansion optimization, noise reduction and energy-saving renovation
Q9: How to protect against lightning and short circuit for 330kV transformers?
- Equip high-performance zinc oxide lightning arresters on HV side to resist overvoltage and lightning surge
- Match dedicated 330kV CSP high-voltage fuse and UHV circuit breaker for rapid fault isolation
- Build reliable integrated grounding system with grounding resistance ≤1Ω
- Deploy complete main and backup relay protection system to realize full-coverage fault early warning and automatic protection trip
