Dual-Voltage Amorphous Alloy Pole-Mounted Transformer for Canadian High-Speed Rail Viaduct Project

Project Overview

DINGXIN developed customized 80sets amorphous alloy dual-voltage single-phase pole-mounted transformers for a high-speed rail viaduct project in Canada.

The transformer is designed with two primary-voltage options—14.4 kV and 8 kV. Because these two voltages do not have a simple proportional relationship, the project required a specially engineered winding and voltage-selection arrangement rather than a conventional series-parallel connection.

Installed along the elevated railway infrastructure, the transformer provides dependable low-voltage power for distributed auxiliary loads such as lighting, monitoring, communications, signaling support equipment, and other electrical facilities.

The project demonstrates DINGXIN’s ability to engineer pole-mounted transformers for special voltage systems, demanding outdoor environments, and infrastructure applications with strict installation requirements.

Project Requirements

The Canadian high-speed rail viaduct project required one transformer design that could accommodate two different primary distribution voltages.

The principal requirements included:

• 14.4 kV and 8 kV selectable primary voltages;
• a non-proportional dual-voltage winding design;
• single-phase operation;
• pole-mounted outdoor installation;
• low no-load losses;
• reliable operation in cold Canadian weather;
• a compact mechanical structure;
• convenient lifting, installation, and cable connection;
• durable sealing and corrosion protection;
• clear voltage-selection and safety identification.

Using a common transformer platform for two primary-voltage conditions also helped the project owner reduce the number of transformer models required across different sections of the railway system.

The Engineering Challenge

Non-Proportional 14.4 kV and 8 kV Primary Voltages

Many conventional dual-voltage transformers use primary voltages with a simple 2:1 relationship. This allows the winding sections to be connected in series or parallel.

The 14.4 kV and 8 kV inputs required for this project do not have that relationship. A standard series-parallel winding arrangement would therefore not produce the correct voltage ratio.

DINGXIN’s engineering team had to calculate the primary winding turns, insulation arrangement, tapping positions, and voltage-selection method specifically for these two system voltages.

The design also needed to ensure that the transformer would deliver the required secondary voltage when connected to either approved primary-voltage source.

Outdoor Railway Operating Environment

Transformers installed beside elevated railway infrastructure may be exposed to:

• low ambient temperatures;
• snow and ice;
• high daily temperature variations;
• moisture and condensation;
• ultraviolet exposure;
• wind and vibration;
• long-term outdoor operation;
• restricted access for maintenance.

Because access to viaduct infrastructure can require traffic coordination, elevated work, or limited maintenance windows, long-term transformer reliability was a major consideration.

Pole-Mounted Installation Constraints

Pole-mounted transformers must balance electrical performance with mechanical limitations. The tank dimensions, total weight, center of gravity, lifting points, mounting brackets, bushings, and cable directions must all suit the installation structure.

The equipment also had to remain compact enough for practical transportation and installation while maintaining the required electrical clearances and insulation performance.

DINGXIN’s Customized Solution

DINGXIN designed an amorphous alloy single-phase pole-mounted transformer around the project’s two primary-voltage conditions and outdoor installation requirements.

Dedicated Dual-Voltage Winding

The primary winding was engineered specifically for 14.4 kV and 8 kV operation.

Instead of using a conventional proportional dual-voltage connection, DINGXIN calculated dedicated winding turns and voltage-selection positions for the two required inputs. This enabled the transformer to maintain the correct transformation ratio under either approved primary-voltage condition.

The voltage-selection arrangement was designed for de-energized operation. Before changing the primary-voltage setting, the transformer must be completely isolated, de-energized, and verified as safe according to the project’s operating procedure.

Clear labels and position identification help reduce the risk of an incorrect voltage setting during installation or maintenance.

Amorphous Alloy Core

The transformer uses an amorphous alloy core to reduce no-load losses.

This is particularly valuable for railway auxiliary power systems, where a transformer may remain energized continuously even when the connected load changes throughout the day.

Lower no-load losses can help:

• reduce continuous energy waste;
• improve transformer operating efficiency;
• lower lifecycle electricity costs;
• support the project’s energy-saving objectives.

Cold-Climate and Outdoor Design

The transformer structure was adapted for outdoor Canadian conditions. Engineering considerations included:

• insulation performance at low temperatures;
• thermal expansion and contraction;
• tank sealing;
• moisture prevention;
• external corrosion protection;
• bushing arrangement;
• mechanical durability;
• outdoor identification and nameplate requirements.

The exact insulation system, protective accessories, coating specification, and operating temperature range were determined according to the approved project specification.

Installation-Oriented Mechanical Design

DINGXIN optimized the transformer’s mounting arrangement, lifting points, bushing locations, and external dimensions according to the pole structure and site interface information.

This installation-oriented approach helped improve:

• lifting convenience;
• pole mounting;
• electrical connection;
• phase and terminal identification;
• inspection access;
• future maintenance.

Main Transformer Features

• Single-phase pole-mounted transformer;
• 14.4 kV and 8 kV selectable primary inputs;
• non-proportional dual-voltage winding design;
• amorphous alloy core;
• reduced no-load losses;
• outdoor sealed construction;
• cold-climate design considerations;
• customized mounting and connection interfaces;
• project-specific voltage labels and nameplate;
• optional protective and monitoring accessories.

Project Value

One Transformer Platform for Two Distribution Voltages

The dual-primary-voltage design allows the same transformer platform to be used in project locations with either a 14.4 kV or an 8 kV power source.

This can simplify equipment standardization, spare-unit planning, technical documentation, and maintenance training.

Lower Long-Term Energy Losses

The amorphous alloy core reduces the energy consumed while the transformer is energized without a significant load.

For railway infrastructure with continuously energized auxiliary power systems, this can create measurable lifecycle energy savings.

Improved Installation Efficiency

The customized pole-mounted structure reduces the need for extensive field modification. Carefully arranged mounting points and electrical interfaces help simplify transportation, lifting, installation, and connection.

Better Adaptation to Canadian Conditions

The outdoor structure, sealing system, insulation design, and corrosion protection were developed around the project environment, improving suitability for cold-weather and long-term outdoor operation.

Case Study Summary

The main challenge of this project was not simply adding another primary tap. DINGXIN had to coordinate a non-proportional 14.4 kV/8 kV winding design with low-loss amorphous alloy technology, outdoor insulation, cold-climate performance, and strict pole-mounted installation limits,Complies with CSA standards

The completed transformer provides the Canadian high-speed rail viaduct project with a flexible and efficient power solution for distributed auxiliary loads.

This case reflects DINGXIN’s ability to develop customized single-phase pole-mounted transformers for special voltage systems and international infrastructure projects.

Need a custom pole-mounted transformer for a special primary-voltage system? Contact DINGXIN to discuss your voltage, capacity, climate, installation, and compliance requirements.