As Alberta continues its transition toward a more diversified and resilient power grid, energy storage became a key part of this project. In 2024 a new grid scale energy storage station in Calgary, Alberta, Canada was needed, and to establish that a fleet of auxiliary transformers was required to support the essential systems within the facility.
Meeting the Demands of Modern Grid Infrastructure
Auxiliary transformers may not be the headline component of any energy storage or power generation project, but they are indispensable for day to day reliability. Daelim was selected to design and manufacture 21 units of 75 kVA / 25 kV auxiliary transformers for that energy storage system.
Each transformer was a custom design transformer with 60 Hz operating frequency, 98.63 % overall efficiency and 4% impedance. They were specifically designed for the operational and safety demands of battery energy storage systems in Alberta, Canada, and therefore have aluminum winding with no load losses of less than 215 watts and load losses of less than 1355 watts.
These units are now an integral part of the energy storage infrastructure. They ensure uninterrupted operation of supporting loads such as the control room, ventilation systems, fire protection and monitoring of sensitive equipment.
As far as this project is concerned, the Daelim role was to design, build and deliver 21 units that would:
- Ensure operational safety in close proximity to high energy battery systems
- Meet all the international and national safety and performance regulations and standards
- Integrate seamlessly with the monitoring and protection system of the energy storage system
All the 21 units were designed and built to comply with CSA C227.4 standards. It is the specific Canadian standard for pad mounted distribution transformers. Following these standards ensures that the transformer will comply with utility and regulatory expectations related to operation and safety.
Engineered for Safety, Designed for the Future
Each transformer was engineered to meet the unique environmental conditions of the Canadian climate and the functional requirements of that specific energy storage station. These conditions and requirements include:
- Fire safety and electrical insulation international standards for an energy storage environment
- A compact transformer design suitable for indoor and near enclosure installations. The transformer had a total weight of 1400 KG, of which 400 KG is the weight of the tank that contains 540 liters of oil
- External access points for safe monitoring and low voltage support systems
- High reliability to resist the temperature swings and altitude conditions typical of southern Alberta
The primary and secondary connections are brought out to clearly labelled terminals, so that site teams can carry out inspection, testing and maintenance work without opening the transformer tank.
Oil temperature and oil level are monitored through panel mounted gauges and sensors, which support the built in monitoring requirement of this project.
Every tap changer position, gauge and protective device is accessible from the front panel. That layout lets technicians read the operating state of a unit and isolate it for maintenance, without disturbing the transformers that are still in service.
Collaborative Development and On Time Delivery
Daelim collaborated closely with the electrical engineering team of the energy storage development project. The work started from understanding the energy storage system requirements and the initial design phase of the electrical transformer, and continued through to the final delivery of all 21 auxiliary transformers.
All 21 units needed for the project were designed, manufactured, and went through the process of factory acceptance test at the Daelim facility, and then were shipped to the Calgary site.
The delivery of the transformers was in a phased sequence aligned with the station construction timeline. Due to clear coordination and flexible logistics, installation was completed without any delays, allowing for site commissioning in early 2024.
Learn more about our auxiliary transformers and the custom options available for energy storage projects.
Project Impact
Operational readiness
Auxiliary systems at the energy storage site are now fully operational and support the redundant, decentralized transformer units.
Safety compliance
All transformers are tested and they comply with CSA C227.4 Canadian standards, ensuring confidence during electrical inspection and system certification.
Designed for long term value
All transformers are built for reliability and durability with minimal maintenance requirements and with built in monitoring systems such as temperature sensors and gauges, oil level sensors and other devices.
Supports clean energy growth
By enabling safe, reliable, and efficient operation of battery storage infrastructure, these transformers play a key role in Alberta’s clean energy transition.
Powering the Backbone of Energy Storage
In electrical energy storage systems, the batteries may take the centre stage, but this project highlights the importance and essential role of auxiliary transformers in ensuring safe, resilient, and stable performance of energy storage systems. With 21 custom built units in operation, this Calgary energy storage station is well positioned to support the grid for its reliability and efficiency.
Follow Up
Daelim Transformers offer auxiliary transformers, power transformers and distribution transformers of all types, sizes, voltage range and power capacity. Each of our transformers is designed in compliance with international standards like IEEE and CSA C227.4. We also offer custom transformers on client requirements.
If you have any questions about Auxiliary Transformers, you can contact our support team for help.
FAQ
What is an auxiliary transformer used for in an energy storage station?
Auxiliary transformers in an energy storage station supply power to supporting systems such as the control room, ventilation, fire protection and monitoring equipment. They ensure these essential loads keep running even when the main battery systems are operating.
Which standard were the transformers built to comply with?
All 21 units were designed and built to comply with CSA C227.4, the Canadian standard for pad mounted distribution transformers, ensuring compliance with utility and regulatory expectations for operation and safety.
What makes these transformers suitable for cold climate projects?
They were engineered for the temperature swings and altitude conditions typical of southern Alberta, with a compact sealed tank, external access points for monitoring, and components selected for high reliability in an unattended energy storage environment.
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