2.5MVA-0.69kV/34.5kV Wind Power Pad-Mounted Transformer Project in Texas, USA

2026-10-22 16:08:12

1次

1. Project Overview | Customized Solution for Texas‑USA Wind Power Pad‑Mounted Transformer and Adaptation to Wind Farm Operating Conditions

Project	Content
Country	USA (Texas)
Industry	Wind Energy
Project Type	Utility On‑shore Wind Farm
Year	2026
Equipment	2.5MVA Wind‑Power Pad‑Mounted Step‑Up Transformer
Capacity	2.5MVA per unit, total 10 units

2. Background

A wind energy developer in Texas, USA required reliable pad‑mounted step‑up transformers for a large‑scale on‑shore wind farm. The project site faces harsh operating conditions including extreme high temperature, large diurnal temperature difference, sand‑dust erosion, thunderstorms and continuous turbine vibration. Meanwhile, the equipment must satisfy strict ERCOT grid‑connection criteria and US customs‑clearance documentation requirements. The customer selected Hengfengshuai Electric to deliver fully customized factory‑integrated pad‑mounted transformer solutions.

3. Customer Requirements

* Comply with ANSI C57, IEEE C57.12.28 standards and ERCOT grid‑connection specifications, meet IEEE 519 harmonic grid access requirement (voltage total harmonic distortion THD ≤5%, single‑harmonic distortion ≤3%)
* Adapt to extreme high‑low temperature swing ‑40℃ ~ +50℃, daily temperature difference up to 35℃; sand‑dust erosion with site dust deposition density up to 0.45 mg/cm²; UV radiation resistance for total annual UV exposure of 6200 MJ/m²; withstand continuous mechanical vibration of 0.5g amplitude, 1‑200Hz frequency band from turbine long‑term operation
* Harmonic resistance & sufficient temperature‑rise margin for fluctuating wind power output: withstand current total harmonic distortion THD up to 20%, extra 15K temperature‑rise margin reserved above ANSI standard limits
* C4‑M heavy‑duty anti‑corrosion & fully‑sealed structure to avoid internal condensation: pass 1440h neutral salt‑spray test per ISO 12944, enclosure protection grade IP54, internal dew‑proof control for relative humidity ≤60% inside cabinet; optional upgrade to C5‑M marine‑grade anti‑corrosion
* Complete set of English technical documents for customs clearance and grid acceptance: including English version FAT report, dimension drawing, test report, O&M manual, bill‑of‑material, calibration certificate of measuring instruments
* Ocean‑going shock‑proof & moisture‑proof packaging for trans‑Pacific shipping: withstand transportation vibration 2‑200Hz, acceleration 1g; moisture‑proof requirement for 45‑day long‑distance ocean transit
Factory pre‑integration, minimize on‑site installation workload: pre‑assemble all accessories in factory, on‑site installation cycle controlled within 8 working‑hours per unit

4. Engineering Solution:2.5MVA‑0.69kV/34.5kV Wind Turbine Pad‑Mounted Step‑Up Transformer

2.5MVA Wind Power Pad-Mounted Transformer for Texas Project

HENGFENGSHUAI supplied total 10 units of customized wind‑power pad‑mounted step‑up transformers, covering full‑chain service including custom R&D, simulation optimization, FAT test, special sea‑transport packaging, full English documentation and remote technical support.

Pad‑Mounted Step‑Up Transformer

2.5MVA 0.69kV/34.5kV Oil‑Immersed Wind Turbine Pad‑Mounted Step‑Up Transformer

Customized Optimization Items

* 60Hz electromagnetic simulation & temperature‑rise margin enhancement: full‑working‑condition electromagnetic simulation under 60Hz US grid; reserved 15 K extra temperature‑rise margin, can stably run continuously under ambient +45℃ extreme high‑temperature environment, short‑time withstand +50℃ peak ambient temperature condition
* Dy11 harmonic‑resistant reinforced copper winding: high‑purity electrolytic copper winding with anti‑harmonic reinforced structure, K‑factor‑4 harmonic‑withstand design, adapt to wind‑farm current THD up to 20%; reduce eddy‑current harmonic additional loss by 28% compared with ordinary winding, Dy11 vector group effectively suppress 3rd‑order harmonic component
* Anti‑vibration reinforced mechanical structure: core‑coil integral compression reinforcement design; passed 1‑200Hz, 0.5g amplitude vibration simulation and type test; anti‑loosening locking structure for all connection fasteners, eliminate hidden danger of loosening caused by long‑term 24‑h continuous turbine vibration
* C4‑M heavy‑duty anti‑corrosion fully‑sealed enclosure: enclosure surface blasting roughness 60‑75 μm, 5‑layer heavy‑duty anti‑corrosion paint system; passed 1440‑h ISO 12944 salt‑spray aging test, UV accelerated aging test for 2000h; fully‑sealed IP54 cabinet structure, double‑layer sealing rubber strip, prevent sand‑dust ingress and internal condensation; service life of enclosure coating ≥20‑years; C5‑M heavy‑marine anti‑corrosion grade is available as optional upgrade

Accessories

* Anti‑pollution high‑voltage bushings: IEEE C57.19 compliant 34.5kV composite antifouling bushing, creepage distance 44 mm/kV, adapt to heavy pollution site ESDD 0.25‑0.6 mg/cm², partial discharge PD＜10 pC@1.5Um, lightning impulse BIL 200 kV
* Temperature controller, Buchholz relay, pressure‑release valve
* 304 stainless steel fasteners for the whole exposed parts, salt‑spray resistant, matching C4‑M anti‑corrosion requirement
* Full set of English drawings, test reports & O&M manuals

5.Selection Table

Parameter	Value
Rated Capacity	2.5MVA, 10 units total
Rated Frequency	60Hz
Rated Voltage Ratio	0.69 kV ±2×2.5% / 34.5 kV (Um=38.5 kV)
Equipment Type	Pad‑Mounted Oil‑Immersed Wind‑Power Step‑Up Transformer
Tap‑Changing Mode	Off‑circuit tap‑changer ±2×2.5%
Cooling Mode	ONAN (ONAF optional)
Vector Group	Dy11
Design Ambient Temperature	Max +45℃ with extra 15K temperature‑rise margin, short‑term peak ambient +50℃ allowable
Winding Material	High‑purity electrolytic copper, harmonics‑resistant reinforced winding(K‑factor 4)
Insulation Level	34.5kV side BIL 200kV; 0.69kV side per ANSI standard
Short‑circuit Impedance	6.5%‑8%
Anti‑corrosion Grade	C4‑M heavy‑duty (C5‑M optional); 1440‑h salt‑spray test qualified
Pollution‑resistant Level	Heavy pollution grade, bushing creepage distance 44 mm/kV
Standard	ANSI C57, IEEE C57.12.28, IEC/IEEE 60076‑16, ERCOT compliant, IEEE519 harmonic requirement
Design Service Life	20 years

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6. Manufacturing Process

* Raw material incoming inspection (copper winding, silicon steel sheet, sealing components): copper material purity ≥99.97%, silicon‑steel‑sheet iron‑loss inspection, sealing‑strip aging‑resistance verification
Winding fabrication & reinforcement treatment for anti‑harmonic & anti‑vibration: adopt K‑factor‑4 reinforced transposition winding process, winding end fixed with high‑temperature resistant binding material, reduce harmonic eddy loss and vibration fatigue
* Core‑coil assembly, winding compression reinforcement for vibration resistance: fixed compression force controlled within tolerance ±5%, anti‑vibration cushion installed between core‑coil and tank, resist long‑term 0.5g continuous vibration
* Enclosure sand‑blasting & multi‑layer anti‑corrosion coating: sand‑blast surface roughness controlled 60‑75 μm; primer‑intermediate‑finish total 5‑layer heavy‑duty anti‑corrosion coating, each‑layer film‑thickness inspected; whole cabinet UV‑resistant paint, pass 2000‑h UV accelerated aging test
* Complete unit assembly, accessories mounting & sealing check: double‑layer rubber‑strip sealing for cabinet door; whole‑unit sealing pressure‑holding test at 50 kPa, keep 12‑h without pressure drop, prevent condensation and sand‑dust penetration
* Factory full‑scope testing (including routine test, dielectric test, temperature‑rise simulation, salt‑spray sample‑verification, vibration‑simulation inspection)
* IPPC certified sea‑worthy packaging: IPPC heat‑treated steel support + plywood crate; install 3D shock recorder optional for transit impact monitoring; internal desiccant moisture‑proof treatment for 45‑day ocean‑voyage requirement

7. Testing & Quality Control

Every unit completes comprehensive factory acceptance test before shipment, witnessed test by SGS/BV is supported.

* Routine Test: winding DC resistance, turns ratio, vector group, no‑load & load loss, short‑circuit impedance
* Dielectric Test: power‑frequency withstand voltage, lightning impulse insulation test
* Temperature Rise Simulation Test: mimic Texas extreme high‑temperature working condition (+45℃ ambient, superimposed harmonic‑loss simulation, verify reserved 15 K temperature‑rise margin)
* Sealing & Anti‑corrosion Validation: salt‑spray ageing test (sample 1440h ISO12944 C4‑M), full unit tightness inspection(50 kPa /12 h no pressure drop)
* Anti‑vibration structural check: simulate 1‑200Hz,0.5g amplitude long‑term turbine vibration; protection interlock function test (Buchholz relay, temperature controller, pressure‑release valve)
* Full FAT (Factory Acceptance Test) report issued in English version

8. Delivery & Installation

* Packaging: Full oil‑filled shipment; IPPC heat‑treated steel support & plywood crate; Equipped with a 3D impact recorder to monitor transportation impacts throughout the entire process
* Logistics: Trans‑Pacific ocean container shipping to US port; moisture‑proof & shock‑proof protection for long sea voyage (resist 45‑day ocean‑transit high‑humidity and transport vibration)
* Document handover: Full English technical package, customs‑clearance documents delivered before shipment
* On‑site work: Hoisting onto concrete pad foundation, cable termination, SAT site acceptance, step‑by‑step energization commissioning; single‑unit on‑site installation work within 8 working‑hours

9. Project Result

All 10 units of pad‑mounted step‑up transformers were successfully delivered to Texas wind farm. After on‑site installation, SAT acceptance and commissioning, the equipment realizes stable long‑term operation. The transformers step‑up generator 0.69kV output to 34.5kV collector system, fully meeting ERCOT grid‑connection requirements and harsh local outdoor operating conditions.