High Voltage 220kV/230kV Step-Down Power Transformer for Substations | 50–500 MVA Oil-Immersed

220kV/230kV 50–500 MVA Oil-Immersed Power Transformer Features

This 220kV/230kV high voltage three-phase oil-immersed power transformer is engineered to meet the rigorous demands of large-scale power transmission and substation applications. With a rated capacity ranging from 50 MVA to 500 MVA, it is ideal for integration into national grids, utility substations, heavy industrial sites, and renewable energy systems.

The transformer features a Delta-connected 220kV/230kV primary winding and supports a wide range of customizable secondary voltages (such as 66 kV, 33 kV, 13.8 kV, or 11 kV) to meet regional grid requirements. Its magnetic core is built using low-loss, high-permeability grain-oriented silicon steel, while windings use high-conductivity copper for enhanced electrical efficiency.

Encapsulated in a weatherproof, corrosion-resistant steel tank, this transformer is filled with mineral insulating oil, offering superior dielectric strength and thermal dissipation. Optional online monitoring systems, OLTC (On-Load Tap Changer), and bushing current transformers can be integrated to improve system reliability and controllability.

Certified to ANSI, IEEE, IEC, UL, CSA, and GOST standards, this transformer is built for long-term durability, low noise operation, and minimal maintenance. It supports OEM customization and is widely supplied to North and South American markets, including the United States, Canada, Brazil, Mexico, Chile, Argentina, Colombia, Bolivia, and Peru.

220kV/230kV 50–500 MVA Oil-Immersed Power Transformer Technical Specs

No.	Item	Specification	Remark
1	Power Rating	50 MVA to 500 MVA	Customizable according to project requirements
2	Primary Voltage	220 kV / 230 kV (Delta or Wye connection)	Standard high-voltage input for substation applications
3	Secondary Voltage	13.8 kV, 33 kV, 69 kV, 115 kV (customizable)	Wide range of output voltages to meet different distribution needs
4	Phase	Three-phase	Compatible with 50Hz or 60Hz frequency
5	Cooling Type	ONAN or ONAF (Oil Natural Air Natural / Forced)	Efficient oil-immersed cooling ensuring thermal stability
6	Core Material	High-quality silicon steel	Low-loss design for improved energy efficiency
7	Insulation Medium	Mineral oil	Excellent insulation performance to prevent overheating
8	Temperature Rise	65°C (ONAN), up to 80°C (ONAF)	Complies with industry safety standards
9	Enclosure	Weatherproof and corrosion-resistant	Suitable for harsh outdoor environments
10	Standards Compliance	ANSI C57.12, IEEE, IEC, UL, CSA	Meets international safety and performance standards
11	Certifications	UL Listed, CE, CSA, SGS	Recognized global quality assurance
12	Connection Options	Delta – Grounded Wye, Wye – Wye, Delta – Delta, Wye – Delta	Flexible connections to adapt to various grid configurations
13	Applications	Substations, utility grids, large industrial facilities	Designed for critical power transmission and distribution
14	Protection Features	Overcurrent, surge, temperature monitoring	Built-in protection to enhance transformer reliability
15	Dimensions & Weight	Customized by capacity and design	Size and weight vary depending on rating
16	Operational Efficiency	High-efficiency design reducing operational losses	Energy-saving and environmentally friendly
17	Transport & Installation	Designed for easy transport and installation	Suitable for urban and remote locations
18	Ambient Temperature Range	-20°C to +50°C	Suitable for diverse climates in North and South America
19	Total Losses (at Rated Load)	1.2% – 1.5%	Low loss design to improve efficiency
20	No-Load Loss	0.2% – 0.5%	Reduced energy consumption during no-load
21	Load Loss	0.8% – 1.0%	Optimized for minimal energy loss under load
22	Impedance Voltage	4.5% – 7.5%	Standard impedance for voltage regulation and efficient energy transfer
23	Short-Circuit Withstand Capacity	30 kA – 60 kA	Meets high short-circuit current requirements
24	Insulation Class	Class A (up to 105°C)	Suitable for long-term operation under high temperature
25	Winding Material	Copper or Aluminum	Copper offers superior conductivity; aluminum is cost-effective
26	Tap Changer Type	On-load tap changer (OLTC) or off-load tap changer	Flexible voltage regulation to ensure system stability
27	Bushing Type	Porcelain or composite	Weather-resistant for harsh outdoor conditions
28	Cooling Oil Volume	800 to 5000 liters	Sized according to transformer capacity for optimal cooling
29	Design Life	30 to 40 years	Engineered for long-term reliable operation
30	Noise Level	60 to 70 dB	Low noise design suitable for various environments
31	Warranty	1 to 3 years	Flexible warranty options based on customer requirements
32	Delivery Time	60 to 90 days	Fast delivery to meet project schedules
33	Lead Time for Custom Orders	120 to 150 days	On-time delivery for large customized projects
34	Price Range	Contact for quotation	Pricing depends on capacity, customization, and shipping location

✅ 220/230kV High Voltage Step Down Oil-Immersed Power Transformer Overview

A 220kV or 230kV oil-immersed step-down transformer is designed for high-voltage transmission networks, stepping down voltages from 220/230kV to 110kV, 66kV, or lower levels. These transformers are three-phase, oil-cooled, and constructed for long-term continuous operation with robust insulation, copper windings, and vacuum-sealed tanks. Suitable for use in substations, renewable energy integration, and industrial grids, these transformers support ONAN/ONAF cooling and are available with on-load tap changers (OLTC). ENERGY TRANSFORMER offers custom configurations certified to IEC, ANSI, GOST, CE, and other global standards.

✅ 220/230kV Substation Step-Down Transformer MVA Ratings (50 MVA to 500 MVA)

220kV/230kV transformers are available in a wide range of power ratings to meet different substation requirements. Typical ratings include 63 MVA, 100 MVA, 150 MVA, 250 MVA, and up to 500 MVA. The MVA rating determines the transformer’s ability to handle power demand across high-voltage grids. ENERGY TRANSFORMER supplies these large-scale transformers to state-owned utilities, industrial megasites, and renewable power stations. Each unit is engineered for optimal cooling, minimal no-load/load losses, and overload protection. Power rating is confirmed through short-circuit, impulse, and temperature rise testing per IEC 60076.

✅ How to Calculate MVA for 220/230kV Electrical Power Transformers

The MVA rating of a transformer is calculated using the formula: MVA = (√3 × Voltage × Current) ÷ 1,000,000. For example, a 230kV transformer handling 251A would be rated around 100 MVA. Proper MVA calculation ensures compatibility with substation equipment, relay protection, and transformer life expectancy. ENERGY TRANSFORMER assists clients with accurate capacity sizing based on load demand, grid topology, power factor, and future expansion. We also provide technical drawings and simulations to help system planners and engineers with transformer integration.

✅ What Is a 230kV High Voltage Step-Down Transmission Transformer?

A 230kV transmission transformer is a high-capacity electrical device used in extra high voltage (EHV) grids to convert power from generation-level voltage to subtransmission levels. These transformers handle high currents, requiring superior insulation, electromagnetic shielding, and seismic support. Typical configurations include star-star or star-delta vector groups, with tap changers for voltage regulation. Applications include national grids, interconnection substations, large-scale PV or hydroelectric power plants. ENERGY TRANSFORMER builds these units with low-loss cores, smart monitoring systems, and customized cooling systems for stable long-term service.

✅ 220/230kV Oil-Immersed Power Transformer Dimensions and Size Guide

The size of a 220kV transformer varies with MVA rating, cooling system, and insulation class. A 100 MVA unit typically measures 6–7 meters in length, 4–5 meters in width, and 4–5 meters in height (excluding bushings and accessories). These units are delivered on heavy-duty skids or trailers and require reinforced concrete foundations. ENERGY TRANSFORMER provides complete dimensional drawings, base layouts, and installation clearances to support substation design. We also offer compact solutions with modular radiators and removable conservator tanks for easier shipping.

✅ 220/230kV High Voltage Transformer Weight and Lifting Specifications

Weight is a critical factor in transportation and installation. A 220kV 100 MVA transformer may weigh 70–90 tons, including core, windings, oil, radiators, and accessories. Total shipping weight can exceed 120 tons with packaging. ENERGY TRANSFORMER ensures every unit is designed with appropriate lifting lugs, center-of-gravity markings, and DNV-certified transport containers for overseas delivery. We support road, rail, and sea transport with onsite unloading, hoisting plans, and crane services if required. Weight data is always included in technical datasheets and layout drawings.

✅ 220/230kV Oil Transformer Price: Factors and Cost Breakdown

The price of a 220kV transformer depends on voltage level, MVA rating, core material (cold-rolled or high-grade silicon steel), winding (copper vs aluminum), insulation level, and special features like OLTC or digital monitoring. For example, a 100 MVA transformer may cost between $400,000–$700,000 depending on options. ENERGY TRANSFORMER offers competitive prices due to full in-house production of core materials, tanks, and windings. We support EXW, FOB, and CIF pricing, with international shipping to over 40 countries. Customized price quotations are available upon request.

✅ 220/230kV Transformer Full Load Current and Amps

The full-load current of a 220kV or 230kV transformer is calculated using: I = MVA / (√3 × Voltage). For instance, a 100 MVA transformer at 230kV has a line current of about 251A. Knowing the current rating helps in selecting bushings, surge arresters, and protection relays. ENERGY TRANSFORMER specifies rated current for both HV and LV sides in all technical documents. We also offer real-time monitoring systems to track load currents, overload protection, and trip settings for safe operation under varying load conditions.

✅ 220/230kV High Voltage Transformer Installation Requirements

Installing a 220kV transformer requires a civil foundation, crane equipment, moisture protection, and proper substation fencing. Oil-immersed transformers must be installed with bund walls, oil drain pits, fire barriers, and grounding systems. ENERGY TRANSFORMER provides complete onsite installation guides, foundation design drawings, and supervision services. Our transformers come with integrated bushings, sealed tanks, radiator modules, and tap changer cabinets. Installation must comply with local electrical codes, IEC/GOST/IEEE standards, and fire safety regulations. Remote monitoring and SCADA integration are optional.

✅ 220/230kV Transformer Tank, Conservator, and Protection Box

The tank of a 220/230kV transformer is a sealed steel enclosure containing the core, windings, and insulating oil. It must withstand internal pressure, oil expansion, and thermal cycling. The conservator tank maintains oil volume during temperature changes and includes silica gel breathers. ENERGY TRANSFORMER tanks feature welded seams, reinforced corners, and anti-corrosion coatings. Protection boxes house the Buchholz relay, OLTC controls, cooling fans, and monitoring devices. Explosion vent, pressure relief device, and liquid level indicators are standard for high-voltage units.

✅ 220/230kV High Voltage Transformer Sizes, Voltage Classes, and Vector Groups

Transformers in this voltage class are generally available for 110/220kV, 230/69kV, 220/66kV, or 230/33kV applications, with vector groups such as YNd1, YNyn0, and Dyn11. Selection depends on network topology, system grounding, and protection coordination. ENERGY TRANSFORMER customizes winding connections, tap changer configurations, and insulation levels to match local utility requirements. All transformers are type-tested for insulation coordination and withstand voltage. Vector groups are clearly marked on nameplates and documents, along with polarity and phase displacement information.

✅ 220/230kV Transformer Windings: Copper vs Aluminum

Windings are the heart of the transformer. At 220kV and 230kV levels, copper is preferred for its high conductivity and mechanical strength. Aluminum may be used for cost-sensitive applications. ENERGY TRANSFORMER offers both options with double shielding, paper insulation, and radial/axial cooling ducts. Winding design affects loss performance, temperature rise, and overload capacity. Our automated winding machines ensure uniform tension and minimal interlayer gaps, reducing hotspots. All windings are tested for impulse, AC withstand, and inter-turn insulation.

✅ 220/230kV Power Transformer Losses and Efficiency

Losses in a high-voltage transformer are classified as no-load (core) losses and load (copper) losses. ENERGY TRANSFORMER designs all 220kV/230kV transformers with low-loss grain-oriented steel and high-efficiency windings to meet or exceed IEC Tier 1/2 standards. A 100 MVA unit typically has ≤45 kW no-load loss and ≤280 kW load loss. Efficiency exceeds 99.6% at full load. Loss data is critical for utility financial modeling and is included on the nameplate. Optional temperature sensors and loss monitors are available for real-time energy analytics.

✅ 220/230kV Power Transformer Standards and Certifications

All 220/230kV transformers from ENERGY TRANSFORMER are manufactured in compliance with IEC 60076, ANSI C57, GOST 11677, CE, and ISO 9001/14001 standards. We offer type test reports including impulse test, temperature rise test, and short-circuit withstand test. Custom certifications such as UL, SASO, or CSA are available upon request. Factory acceptance tests (FAT) are conducted before shipment, and we welcome third-party inspections. All documentation, including installation manual, maintenance guide, and test reports, is provided in English and Russian.

✅ 220/230kV Transformer Nameplate: What to Expect

The nameplate on a high-voltage transformer provides key technical details: manufacturer, model number, rated power (MVA), voltage class, vector group, frequency, weight, oil volume, cooling method, standard compliance, serial number, and year of manufacture. ENERGY TRANSFORMER includes QR codes for digital access to datasheets and tracking. Nameplate information is crucial for maintenance, grid synchronization, and spare parts. Dual-language (English & Russian) plates are available for CIS markets.

✅ 220/230kV Power Transformers for Sale: Global Supply and Delivery

ENERGY TRANSFORMER offers 220/230kV power transformers for sale with fast delivery worldwide. We maintain flexible production capacity and export-ready stock for standard MVA ratings. Whether for public tenders or private EPC projects, we provide complete logistics, packaging, and shipping support. Our transformers are already operating in over 40 countries, including Russia, Brazil, UAE, Kazakhstan, and South Africa. Pre-sales consultation, after-sales technical support, and 24/7 online assistance are included in our service scope.

220kV/230kV Power Transformer Core Structure and Assembly Process

Why Choose High Voltage 220kV/230kV Step-Down Power Transformer for Substations (50–500 MVA, Oil-Immersed)?

Energy Transformer’s 220kV/230kV Step-Down Power Transformer is specifically designed to meet the high-voltage requirements of modern substations. With a power range of 50 MVA to 500 MVA, this oil-immersed transformer ensures secure, efficient, and stable voltage transformation from transmission to distribution levels, making it ideal for large-scale infrastructure and energy-intensive industries.

✅ High Voltage Step-Down Capability

Designed to reduce transmission voltage from 220kV/230kV to usable distribution levels, this transformer ensures safe and efficient integration into national or regional power grids.

✅ Wide Power Range from 50 to 500 MVA

Suitable for a variety of applications, including major substations, steel plants, renewable energy bases, and interconnection projects across global power networks.

✅ Advanced Oil-Immersed Cooling System

Equipped with optimized oil circulation and radiator systems, this design guarantees superior thermal management for prolonged and stable operation under continuous load.

✅ Heavy-Duty Construction for Harsh Environments

The transformer features a rigid tank body, reinforced core clamping, and precision windings, offering exceptional mechanical strength and resistance to short circuits and overloads.

✅ International Standards & Certifications

Fully compliant with IEC, GOST, CE, IEEE, ANSI, and other global standards, ensuring compatibility and safety in international power projects.

✅ High Efficiency and Low Loss

Engineered with low-loss silicon steel and optimized magnetic circuits to minimize no-load and load losses, reducing energy waste and operating expenses.

✅ Custom Engineering Options

Available with customizable voltage ratios, ONAN/ONAF cooling types, OLTC/DETC tap changers, and protection systems tailored to your technical and environmental requirements.

✅ Fast Turnaround and Global Logistics

Manufactured in our advanced factory, we ensure lead times within 90 days and deliver worldwide, including Europe, Central Asia, North and South America, and the Middle East.

✅ Competitive Direct-from-Factory Pricing

With in-house R&D and full-scale production, Energy Transformer guarantees high performance with factory-direct pricing to maximize your project’s return on investment.

Whether for national grid expansion, utility substation upgrades, or renewable integration, the 220kV/230kV 50–500 MVA Oil-Immersed Step-Down Power Transformer by Energy Transformer is your trusted solution for safe, scalable, and sustainable power distribution.

📩 Get in touch now for custom quotes, technical specs, or expert engineering support tailored to your substation project!