20kV 2500kVA Three Phase Low Loss Distribution Transformer | ZTELEC YUGUANG

Product Overview

The 20kV 2500kVA three-phase low-loss distribution transformer by ZTELEC YUGUANG represents a new generation of high-efficiency power distribution equipment. Designed with advanced oil-immersed technology, it enhances power supply capacity, ensures superior voltage stability, and significantly reduces system energy losses. Its optimized performance supports both cost savings and improved energy efficiency across industrial and utility power networks. With available capacities ranging from 100kVA to 3000kVA, this transformer is suitable for substations, commercial complexes, manufacturing plants, and critical infrastructure.

Coil and Winding System

High-Voltage Winding (20kV)

The high-voltage winding uses a multi-layer cylindrical structure with copper or aluminum conductors wrapped in durable DMD insulation. This configuration ensures balanced ampere-turn distribution, strong short-circuit resistance, reduced magnetic leakage, and improved dielectric performance.

Low-Voltage Winding (0.4kV)

The low-voltage winding features a copper foil coil design, minimizing eddy current losses, improving heat dissipation, and providing excellent performance under long-term heavy loads.

Insulation Technology

The transformer adopts a complete Vacuum Pressure Impregnation (VPI) process with H-class insulation materials capable of handling temperatures up to 180°C, ensuring long-term thermal endurance and electrical reliability.

Core and Magnetic Circuit System

The magnetic core is made from high-permeability cold-rolled silicon steel sheets such as 30ZH120, using a precision step-lap lamination process. This construction significantly reduces no-load loss (S13 series achieves approximately 30% lower losses compared to S11), decreases magnetostriction noise, and enhances operating efficiency. Mechanical stability is strengthened through the use of self-locking fasteners and a vibration-resistant suspended core structure.

Cooling & Insulation System (ONAN)

The 20kV 2500kVA transformer from ZTELEC YUGUANG uses high-quality naphthenic mineral oil or synthetic ester oil with a breakdown voltage of ≥40kV at 20°C. Its cooling relies on natural oil circulation and natural air cooling (ONAN), ensuring noise-free and maintenance-free operation. A corrugated oil tank or panel radiator provides efficient thermal regulation, automatically adjusting oil volume during temperature changes.

Sealed Oil Tank & Structural Protection

The fully sealed corrugated oil tank eliminates the need for an oil conservator and prevents external contaminants from entering the system. This design ensures stable internal pressure, reduces maintenance requirements, and extends service life. Equipped with an IP55 protection level and anti-corrosion coating, the transformer performs reliably in humid, dusty, or coastal environments.

Protection and Monitoring Devices

The ZTELEC YUGUANG transformer integrates essential protection features such as a gas relay for internal fault detection, a pressure relief valve activated at ≤70kPa, and a temperature controller with a PT100 remote transmission interface. These devices enhance operational safety and provide real-time monitoring for stable long-term service.

Voltage Regulation (Tap Changer)

The high-voltage side is equipped with an off-load tap changer with a ±5% tapping range and 3–5 selectable positions, allowing manual adjustment to match varying grid voltage conditions.

Bushing and Terminal Design

High-voltage bushings are available in porcelain or silicone rubber composite materials, offering a creepage distance ratio of ≥25mm/kV and excellent flashover resistance. Low-voltage bushings use resin-cast construction with anti-pollution features and tin-plated terminals to ensure stable, oxidation-free connections.

Why Choose This Transformer?

This 20kV 2500kVA low-loss distribution transformer by ZTELEC YUGUANG delivers outstanding performance, including ultra-low losses, high short-circuit endurance, reliable ONAN cooling, and maintenance-free operation. It is ideal for demanding applications in urban distribution networks, heavy industry, and high-load commercial installations. Its robust design ensures long-term stability, precise voltage control, and consistent power delivery in harsh environments.

Product Specifications