33/35kV High-Capacity Oil-Immersed Transformer

35kV Oil-immersed Distribution Transformer

Medium-high voltage, IEC/GOST certified oil-immersed transformer for 33/35kV regional grid interconnection and industrial power supply

Overview

Key Applications

Why Choose？

Engineering

Technical Specifications

Customization

Support

Overview

The TSTY 33/35kV oil-immersed transformer steps down medium-high voltage (33/35kV) to 10kV or 0.4kV, serving as the critical interface between 110kV main grids and regional distribution networks. Available from 200kVA to 31,500kVA, it is engineered for high-load, long-distance power transmission in heavy industry and renewable energy integration.
Unlike standard distribution transformers, this unit prioritizes dielectric strength and overload resilience to handle significant load fluctuations in mining, petrochemical, and utility substation applications. All units feature reinforced oil-paper insulation, premium mineral insulating oil, and corrosion-resistant galvanized hardware for decades of reliable service in demanding environments.

Key Applications

Commonly specified for projects where medium-high voltage transformation, high overload capacity, and compliance with 35kV grid codes are non-negotiable.

Regional substations and 110/35kV step-down stations

Large-scale industrial parks and manufacturing bases

Renewable energy collection stations (wind/solar farms)

Mining and petrochemical facilities with heavy motor loads

Long-distance rural electrification and grid reinforcement

High-capacity commercial infrastructure requiring dual-voltage output

Why Choose 33/35kV Oil-immersed Distribution Transformer?

All units feature 100% copper windings, premium mineral insulating oil, and corrosion-resistant galvanized hardware for decades of reliable service.

Reinforced dielectric design

Enhanced oil-paper insulation system with optimized winding spacing withstands 35kV switching surges and lightning impulses, ensuring stable operation in electrically noisy industrial environments.

High-overload structural resilience

Optimized core-winding geometry and cooling duct design accommodate sustained 120% overload during peak demand or contingency scenarios without accelerated aging.

Dual-voltage output flexibility

Factory-configurable secondary outputs (10kV or 0.4kV) eliminate the need for additional step-down transformers, reducing footprint and total cost of ownership in multi-tier distribution networks.

Heavy-duty mechanical construction

Reinforced tank walls and clamping structures resist transportation stress and seismic forces, meeting site-specific installation requirements for remote or seismically active zones.

Low-acoustic emission

Noise levels consistently below national limits through precision core stacking and vibration-damping mounts, enabling deployment near residential boundaries or noise-sensitive facilities.

Engineering & Global Compliance

Every TSTY 33/35kV oil-immersed transformer integrates advanced manufacturing with internationally recognized quality and safety frameworks:

Project-specific engineering validation

Dedicated engineers review client-provided single-line diagrams, ambient data, and grid codes to verify design compatibility before production, preventing field rework due to mismatched specifications.

Full-chain material traceability

All core steel, copper conductors, and insulating oils are sourced from ISO-certified suppliers with batch-level documentation; incoming materials undergo pre-production testing to ensure consistency across every unit.

35kV-specific insulation verification

Each unit undergoes partial discharge measurement and induced voltage withstand tests tailored to 33/35kV class requirements, confirming insulation integrity under medium-high voltage stress beyond standard distribution-level checks.

Site-adaptive performance validation

Units are tested against project-specific ambient temperature ranges, altitude corrections, and harmonic distortion profiles to guarantee rated performance under actual operating conditions, not just laboratory baselines.

Technical Specifications

Standard configurations for 200–31,500kVA 33/35kV oil-immersed distribution transformers

50-2500KVA 33-35KV Oil-immersed transformer

Rated Capacity (kVA)	Voltage Combination			Vector Group	No-Load Loss(w)	Load Loss	No-Load Current (%)	Short Circuit Impedance (%)
Rated Capacity (kVA)	High Voltage（kV)	Tapping Range	Low Voltage (kV)	Vector Group	No-Load Loss(w)	Load Loss	No-Load Current (%)	Short Circuit Impedance (%)
50	33 35	±5% ±2×2.5%	0.4	Dyn 11 or Yyn0	170	1200	2.1	6.5
100					230	2010	2.0
125					270	2370	1.5
160					290	2820	1.4
200					340	3320	1.3
250					400	3950	1.2
315					480	4750	1.1
400					580	5740	1.0
500					680	6910	1.0
630					830	7860	0.9
800					980	9400	0.8
1000					1150	11500	0.7
1250					1400	13900	0.6
1600					1690	16600	0.6
2000					1990	19700	0.6
2500					2360	23200	0.6

*Standard vector group: Dyn11. Custom configurations (e.g., Yyn0, special taps, noise-reduction design) available upon request.

Customization & Optional Features

Every TSTY 33/35kV oil-immersed transformer is built to order. Standard units comply with IEC 60076, while optional features are factory-integrated and fully tested:

Enclosure material selection

Choose between galvanized steel for standard outdoor durability or stainless steel for highly corrosive coastal/chemical plant environments; custom RAL color matching available for site aesthetics.

Oil expansion system configuration

Select sealed-tank design for zero-maintenance operation in stable climates, or conservator with oil pillow for high-altitude or extreme-temperature sites requiring pressure equalization.

Voltage regulation strategy

Specify off-circuit tap changer for fixed-ratio applications, or on-load tap changer (OLTC) with custom step voltages and position counts for dynamic grid support; tap ranges adjustable to match local utility tolerance bands.

Installation & mobility adaptation

Opt for fully welded sealed enclosure to eliminate gasket maintenance, or add heavy-duty casters and jacking pads for indoor substation positioning where overhead cranes are unavailable.

Condition monitoring integration

Add WTI/OTI sensors with analog/digital outputs and alarm/trip contacts for SCADA integration; optional gas-in-oil monitors available for early fault detection in critical assets.

Efficiency target alignment

Customize no-load and load losses to meet project-specific lifecycle cost models or local regulatory tiers (e.g., S20/S22), rather than defaulting to generic efficiency classes.

Physical & labeling customization

Adjust overall dimensions, bushing clearances, and mounting hole patterns to fit existing foundation footprints; nameplates available in bilingual formats or with QR codes linking to digital manuals.

Support & Documentation

IEC-compliant datasheets and one-line diagrams

Full type-test reports (lightning impulse, etc.)

Installation, operation & maintenance manuals

Regional technical support: 24/7 engineering assistance + spare parts hubs in Asia, Africa, and the Middle East

33/35kV High-Capacity Oil-Immersed Transformer | TSTY

Resource

33/35kV High-Capacity Oil-Immersed Transformer | TSTY

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