11kV & 33kV On-Load
Tap-Changing Transformers

Steema Transformers and Electricals (U) Ltd.
Dynamic Voltage Control with 11kV & 33kV On-Load Tap-Changing Transformers

Steema Transformers and Electricals (U) Ltd. offers advanced on-load tap-changing (OLTC) transformers in the 11kV and 33kV ranges, with capacities spanning 200kVA to 16MVA. These sophisticated electrical devices dynamically adjust the transformation ratio while the transformer remains under load. This real-time voltage regulation capability provides significant advantages over conventional transformers, enhancing grid stability, improving operational economy, and offering superior adaptability for critical power applications. In modern power systems, particularly in key scenarios, our on-load tap-changing transformers are essential for maintaining efficient and reliable power delivery. As power electronics and Internet of Things technologies continue to evolve, Steema’s OLTC transformers are poised for further performance enhancements, contributing to the realization of smart grids and supporting “dual carbon” emission reduction goals.

Key Features

Intelligent On-Load Capacity Adjustmen

Our OLTC control system monitors the voltage and current on the low-voltage side, determining the real-time load. Based on capacity adjustment commands, it executes seamless tap switching, enabling automatic capacity conversion of the transformer to optimize performance under varying loads.

Enhanced Efficiency

The intelligent load capacity adjustment technology integrated into our OLTC transformers effectively reduces both no-load and load losses, leading to significant energy savings.

User-Friendly Operation and Low Maintenance

Steema's on-load tap-changing transformers are designed for ease of use and operation, with a focus on minimizing maintenance requirements and costs. Their inherent low no-load and load losses contribute to energy efficiency and environmental responsibility.

Ideal for Fluctuating Loads

These transformers are particularly well-suited for applications experiencing significant variations in electricity consumption, such as industrial and mining enterprises, as well as power grid infrastructure upgrades.

Environmental Conditions

Normal Service Conditions:

  • Altitude: Below 4000 meters above sea level.
  • Ambient Temperature: Maximum +40 ℃, Minimum -25 ℃.
  • Relative Air Humidity: ≤80% at +25℃.
  • Installation Site: Free from corrosive gases and significant dust accumulation.
Operating Conditions Image

Product Standards

Steema Transformers and Electricals (U) Ltd.’s on-load tap-changing transformers comply with the following standards:

Uganda Bureau of Standards (UNBS) certified
IEC 60076 Power Transformers

Advanced Manufacturing & Reliability at Steema

Reliable Insulation Technology

Steema Transformers and Electricals (U) Ltd. employs high dielectric strength mineral oil, meticulously processed through vacuum oil filtration to eliminate moisture. Our structural design incorporates multi-layered pressboard and oil ducts arranged to optimize the electric field gradient, creating a robust stepped insulation system. Manufacturing processes include vacuum drying and vacuum oil impregnation to ensure comprehensive insulation integrity. Furthermore, rigorous insulation testing is conducted before dispatch to guarantee reliable performance.

Minimized Partial Discharge

During the design phase, Steema meticulously analyzes and controls the electric field strength at every critical point. Coupled with stringent quality assurance protocols, reliable processing methods, and optimized operational procedures, these measures effectively minimize partial discharge within our transformers, ensuring long-term reliability.

Precise Coil Temperature Field Analysis

Through collaborations with leading academic institutions and our dedicated technical research and development team, Steema utilizes advanced coil temperature field calculation programs. These programs accurately determine loss distribution (resistance loss, eddy current loss, circulating current loss) and analyze flow field cooling conditions. This enables precise calculation of coil temperature distribution and hot spot temperature rise, allowing us to implement effective measures to control hot spot temperatures that can impact transformer lifespan.

Steema Transformers and Electricals (U) Ltd.
Your Trusted Power Partner in Uganda

Steema Transformers and Electricals (U) Ltd. is a leading transformer manufacturer and supplier in Uganda, committed to delivering high-quality power solutions. Our advanced manufacturing facilities and experienced team ensure that our 11kV and 33kV on-load tap-changing transformers meet the highest standards of reliability and performance.

Our 11kV and 33kV on-load tap-changing transformers are vital for maintaining stable and efficient power distribution in various applications across Uganda

Contact Steema Transformers and Electricals (U) Ltd. Today:

For more information about Steema Transformers and Electricals (U) Ltd.’s range of on-load tap-changing transformers

(+256) 704 950 155

We are eager to partner with you to build a more reliable and efficient power infrastructure for the future!

Quick Inquiry

"*" indicates required fields

This field is for validation purposes and should be left unchanged.