High Voltage Power Transformer
Unicore’s high voltage power transformers are designed for transmission and primary distribution networks across voltage classes from 35kV to 750kV — covering step-up, step-down, and long-distance power transmission applications in substations, power plants, industrial parks, and large-scale renewable energy projects worldwide.
Built around optimised electromagnetic structures, high-quality silicon steel cores, and reinforced tank construction, our high voltage power transformer delivers low loss, low noise, stable temperature rise, and strong short-circuit withstand capability.
Custom Transformer Solutions
Voltage: 35-750 kV
Capacity: 6300-63000 kVA
Frequency: 50/60 Hz
Access Top Quality Transformer Solutions to Elevate Your Power Projects
Reliable High Voltage Power Transformer For Sale
Best Price HV and EHV Power Transformer
Our high-voltage power transformers are available in standard capacities from 6,300 kVA to 63,000 kVA, with voltage classes spanning 35kV to 750kV — including 66kV, 110kV, 132kV, 220kV, 330kV, 400kV, and 500kV. Tap range, medium voltage, low voltage, connection group designation, no-load loss, load loss, and short-circuit impedance are all configurable to your specific project and grid requirements.
Stable temperature rise under continuous full-load operation
Optimised electromagnetic design for low no-load and load losses
High-quality CRGO silicon steel core for efficient energy conversion
Reinforced tank construction with strong short-circuit withstand capability
Low noise design suitable for substation and urban environments
Reliable insulation system engineered for long operational service life
110kV Power Transformer Sample Specifications — Full Data for All Series Available Upon Request
Specifications
| Rated Capacity (kVA) | Voltage Combination and Tap Range | Connection Group | No Load Loss (kW) | Load Loss (kW) | No Load Current (%) | |||
| High Voltage (kV) | High Voltage Tap Range (%) | Medium Voltage (kV) | Low Voltage (kV) | |||||
| 6300 | 110 | ±4×1.25 ±6×1.25 ±8×1.25 | 36 37 38.5 | 6.3 6.6 10.5 21 | YNyn0dl1 | 7.7 | 42 | 0.61 |
| 8000 | 9.2 | 50 | 0.61 | |||||
| 10000 | 10.9 | 59 | 0.57 | |||||
| 12500 | 12.9 | 70 | 0.57 | |||||
| 16000 | 15.4 | 86 | 0.54 | |||||
| 20000 | 18.2 | 101 | 0.54 | |||||
| 25000 | 21.6 | 120 | 0.5 | |||||
| 31500 | 25.7 | 142 | 0.5 | |||||
| 40000 | 308 | 170 | 0.46 | |||||
| 50000 | 36.4 | 202 | 0.46 | |||||
| 63000 | 43.3 | 243 | 0.42 | |||||
| Currently providing step-down structure products. Other voltage combination products can also be provided according to user requirements. The capacity distribution of high, medium, and low voltage windings is (100/100/100)%. According to user requirements, the connection group designation can also be YNdl1y10. According to user requirements, the medium voltage can use voltage values different from those in the table or have tap changers. Under operating conditions, fewer tap positions are preferable. | ||||||||
Discover Core Advantages of Transformers to Optimize Your Power Layout
Remarkable Advantages of Unicore High Voltage Power Transformer
Optimised Electromagnetic Design
Each Unicore high voltage power transformer is designed with an optimised electromagnetic structure that minimises flux density, reduces core losses, and improves overall energy conversion efficiency — delivering measurable reductions in no-load losses that translate directly into lower lifetime operating costs for your substation or transmission network.
Step-Up and Step-Down Configurations
Unicore high-voltage transformers are available in both step-up and step-down configurations, supporting power plant generator connections, transmission network injection points, primary substation voltage conversion, and industrial high-voltage power intake — covering every directional power flow requirement across your project scope.
Reinforced Tank Construction
Every Unicore high-voltage power transformer tank is engineered with reinforced steel construction to withstand the mechanical stresses of short-circuit events, transportation loads, and long-term operational pressure — providing structural integrity and protection for the active parts throughout the transformer’s service life in demanding substation environments.
Renewable Energy Project Ready
Our high voltage power transformers are increasingly specified for large-scale solar, wind, and hydropower projects — where grid connection transformers must meet precise voltage ratio, harmonic tolerance, and loss performance requirements. Our engineering team has experience supporting renewable energy developers across multiple continents and grid standards.
Strong Short-Circuit Withstand Capability
Unicore high voltage transformers are designed and tested to withstand the full dynamic and thermal stresses of short-circuit fault conditions — protecting your substation investment and maintaining network continuity under the most severe fault scenarios your grid protection system may encounter.
Stable Temperature Rise Performance
Our thermal design ensures stable, controlled temperature rise under continuous full-load operation — with cooling systems configured to maintain winding and oil temperatures within IEC 60076 limits, extending insulation life and reducing the risk of thermal degradation over the transformer’s operational service life.
Trusted by Clients Across Industries and Continents
Unicore High Voltage Power Transformer Global Cases
High Voltage Power Transformer to South Africa
Primary Substation – Transmission Network
40,000 kVA
High Voltage Power Transformer to Morocco
Renewable Energy Grid Connection – Solar Farm
25,000 kVA
High Voltage Power Transformer to Ecuador
Industrial Power Intake – Mining Operation
16,000 kVA
UNICORE ELECTRIC
Transformer Solutions
Collaborating with Industry Leaders to Deliver Excellence in Power Solutions
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Real Experiences from Transformer Professionals Who Trust Unicore
What Our Clients Say
Great Performance For Our Transmission Network
“We specified Unicore’s 110kV high-voltage power transformer for a critical primary substation upgrade. The electromagnetic design delivered exactly the low-loss performance our grid operator required.”
Ibrahim Al-Farsi
Saudi Arabia
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Perfect Short-Circuit Withstand Capability
“Operating in an industrial environment with frequent fault events, short-circuit withstand capability was our primary selection criterion. Unicore’s high-voltage transformer has now been in service for three years through multiple fault incidents without any structural or insulation issues.”
Sofia Andrade
Chile
⭐⭐⭐⭐⭐
Explore Precision Engineering Configurations Built for Superior Grid Stability
Technical Excellence and Manufacturing Specifications
High-Permeability Core Architecture
UNICORE utilizes premium grain-oriented silicon steel with a specialized step-lap joint. This precision engineering achieves a 30% reduction in no-load losses and noise levels below 65dB, ensuring high-efficiency and quiet operation for modern urban power transmission and distribution networks.
-30% No-load Loss
below 65dB
Advanced Vacuum Insulation Technology
Integrating premium pressboard with vacuum-degassed mineral oil, we achieves partial discharge levels under 10pC. This high-grade insulation prevents thermal aging and effectively extends the transformer’s operational lifespan to over 30 years in the harshest global environments.
<10pC PD Level
30+ Year Life
High-Purity Copper Winding Systems
Our coils feature 99.9% oxygen-free copper treated through specialized vacuum drying technology. This design ensures the mechanical rigidity to withstand short-circuit forces up to 20 times the rated current, guaranteeing total grid safety and reliability during extreme fault scenarios.
99.9% Pure Copper
20x Current Proof
Integrated Precision Voltage Regulation
Equipped with high-precision On-Load Tap Changers, UNICORE offers a standard regulation range of ±8 × 1.25%. This system provides seamless real-time voltage adjustment to compensate for grid fluctuations, ensuring stable power delivery without any interruption to sensitive equipment.
±8×1.25% Range
Seamless Control
Cost Engineering Insights
What Factors Determine the Cost of a High Voltage Transformer?
1. Conductor Material (Copper vs. Aluminum)
The winding material you select directly impacts your initial purchase price. While we offer cost-effective aluminum options, we typically specify pure copper for high-performance grids. Copper gives your system superior electrical conductivity, better heat dissipation, and a longer lifespan. Your higher upfront material cost is naturally balanced by the energy and maintenance savings you gain over time.
2. Precision Manufacturing and Labor Costs
We cannot fully automate high-voltage coil manufacturing. To ensure strict insulation integrity, our coil assembly requires precise manual winding by our experienced technicians. This skilled labor process increases our manufacturing time and base costs, but it is essential to prevent insulation micro-damage and ensure your transformer withstands severe electrical stress.
3. High-Grade Insulation Components
Because your equipment operates under high voltage, it requires a heavy-duty internal insulation system. During manufacturing, we utilize premium electrical insulating tapes and high-density pressboards to securely fix the windings. The high volume of these specialized materials adds to the cost, but they are critical for preventing internal short circuits and extending your equipment’s lifecycle.
4. Wire Diameter and Physical Specifications
We scale the physical dimensions of the internal conductors based on your specific load requirements. If your project needs to handle higher currents or minimize thermal loss (I²R), we will design the unit using conductors with larger wire diameters. Thicker wire requires us to consume significantly more raw copper or aluminum, which adjusts the pricing to reflect your customized material volume and higher efficiency rating.
Navigating Voltage Classifications
Which Voltage Tier Does Your Project Require?
Low Voltage Distribution (< 1kV)
Operating below 1,000 volts, low voltage represents the final stage of power delivery. When we design distribution systems for your commercial or residential environments, we specifically step down the voltage to prioritize human safety. You utilize this tier directly for standard building distribution and lighting, as it directly powers your end-user appliances without requiring further large-scale transformation.
Medium Voltage Networks (1kV – 35kV)
Ranging from 1kV to 35kV, medium voltage handles localized power distribution. If you operate an urban substation, a large manufacturing plant, or a mining facility, your infrastructure relies on this tier. We utilize medium voltage capacity to drive your heavy industrial machinery and power large commercial complexes, satisfying local energy demands that far exceed what a standard residential grid can support.
High Voltage Transmission (35kV – 230kV)
Ranging from 35kV to 230kV, high voltage electricity is exclusively utilized for bulk power movement from large-scale generation plants. If your project involves long-distance grid transmission, this is the operational tier you require. By exponentially stepping up the voltage, we help you proportionally reduce the electrical current—the only effective physical mechanism to minimize thermal energy loss (I²R losses) when moving alternating current across your regional networks.
Extra & Ultra-High Voltage (≥ 230kV)
Extra High Voltage (230kV-1000kV) and Ultra-High Voltage (≥1000kV) handle the absolute highest tiers of power delivery. You will require these levels when managing inter-regional backbone networks. We engineer systems at this extreme scale to help you transport massive cross-country electrical capacity from remote mega-generating stations directly to your major regional distribution hubs.
Delivering High-Voltage Stability for Mission-Critical Global Energy Sectors
High Voltage Transformer Applications and Industry Solutions
Powering Utility Grid Substations
UNICORE transformers serve as the critical link in national and regional transmission networks. Engineered for extreme reliability, they stabilize long-distance power flow and ensure efficient energy delivery to urban centers and residential grids with minimal transmission loss and maximum stability.
- 66kV – 220kV Range
- Grid-Ready Design
Renewable Energy Plants
Optimized for large-scale solar PV parks and wind farms, UNICORE GSU units manage variable loads and harmonic stress. Our transformers facilitate efficient grid injection, maximizing the levelized cost of electricity for renewable energy developers across diverse climates.
- Harmonic Optimized
- Low-Loss Step-Up
Heavy Industrial Complexes
Providing high-capacity power for steel mills, mining operations, and petrochemical complexes, UNICORE units withstand intensive operational cycles. We can ensure a 24/7 continuous electricity supply to prevent costly downtime in energy-intensive and harsh industrial environments.
- High Load Factor
- 24/7 Operational
Critical Public Infrastructure
Supporting high-speed rail, international airports, and massive data centers, our transformers deliver the precise voltage control required for modern tech hubs. They are engineered to meet the high-availability demands of mission-critical public and digital infrastructure.
- Precise Regulation
- High Availability
Ensuring Peak Operational Performance Through Strict Laboratory Verification
UNICORE International Compliance Standards
Following successful factory verification, we manage the critical phases of project execution to ensure operational success. Our team coordinates specialized heavy-load logistics and provides comprehensive on-site technical guidance, from structural assembly to final energization. This integrated service model minimizes installation risks and ensures that every high-voltage unit is optimized for the specific demands of your grid environment.
International Standard Alignment
Every UNICORE unit complies with IEC 60076 and IEEE/ANSI C57 standards. This ensures total grid compatibility and reliable performance for global utility and industrial power infrastructure projects.
100% Routine Testing Protocol
We execute 100% routine testing, covering winding resistance, voltage ratio, and phase displacement. This mandatory validation ensures zero-defect delivery and eliminates commissioning risks for international contractors.
Advanced Type and Special Tests
Advanced laboratories perform 1.2/50μs lightning impulse and full-load temperature rise tests. These simulations verify structural integrity against surge voltages and ensure stable thermal performance under continuous operation.
Raw Material Quality Control
Materials undergo spectral analysis and moisture testing before assembly. We maintain insulation oil below 10ppm moisture and 0.5% gas content to ensure maximum dielectric insulation stability.
Fundamentals of Grid Transmission Equipment
Understanding High Voltage Power Transformers: Mechanisms and Core Functions
1. Equipment Definition and Scope
A high-voltage power transformer is a heavy-duty, static electrical apparatus precision-engineered to handle extreme voltage levels, typically ranging from 66kV to over 500kV. Beyond simple conversion, it acts as the critical connecting node between multi-gigawatt power generation plants, ultra-high-voltage (UHV) long-distance transmission lines, and regional distribution substations. These units are built with reinforced structural integrity and advanced dielectric insulation systems to ensure continuous operation under the most demanding environmental and load conditions.
2. Electromagnetic Operating Principles
Operating on Faraday’s law of electromagnetic induction, the transformer utilizes alternating current in a primary winding to generate a fluctuating magnetic flux within a high-permeability grain-oriented silicon steel core. This magnetic field seamlessly induces a mathematically transformed voltage in the secondary winding—stepping the voltage either up or down while maintaining the same electrical frequency and maximum stability. Modern UNICORE designs incorporate step-lap core technology and optimized winding geometry to minimize eddy current losses and ensure peak energy conversion efficiency exceeding 99%.
3. Core Functions in Power Transmission
Its ultimate function is to maximize energy transmission efficiency over vast distances and complex grid topologies. By drastically stepping up the voltage for long-haul transport, the transformer proportionally reduces the electrical current. This process minimizes (thermal) energy losses across transmission lines, ensuring stable, cost-effective, and safe power delivery to end-user grids. Furthermore, integrated precision voltage regulation components allow the transformer to actively compensate for grid fluctuations, protecting sensitive downstream industrial infrastructure.
Why Choose Unicore
Your Trusted Partner in Power Solutions
When a high voltage power transformer fails, the consequences extend far beyond the equipment itself — delayed energisation, grid operator rejection, and project cost overruns follow. Unicore high-voltage power transformers are built to eliminate those risks, with engineering depth, certification credentials, and project support that match the demands of transmission-level procurement.
Engineered for Long-Term Grid Service
Optimised electromagnetic design, premium CRGO silicon steel cores, reinforced tank construction, and precision vacuum oil-filling processes combine to deliver stable performance, low thermal degradation, and reliable dielectric integrity throughout decades of continuous transmission network operation.
Renewable Energy Grid Connection Ready
Unicore high voltage power transformers are increasingly specified for solar, wind, and hydropower grid connection applications — where precise voltage ratio, harmonic tolerance, and low-loss performance are critical for grid operator acceptance and long-term generation efficiency across the project’s operational lifetime.