Pohang, South Korea – January 2026 – POSCO, one of the world’s leading steel producers, has successfully deployed ABB DKTFM418B 3BHB015651P0001 Thyristor Triggering Modules to upgrade the power control systems of 8 electric arc furnaces (EAFs) at its Pohang steelworks. The deployment, completed in Q4 2025 after a three-month pilot phase, addressed critical issues with legacy thyristor triggering components, including unstable triggering signals, high energy losses, and frequent furnace shutdowns. Six months of post-implementation data shows a 38% reduction in energy losses, a 52% decrease in unplanned downtime, and a 22% improvement in smelting efficiency—key milestones in the company’s goal of achieving carbon neutrality by 2050.
The Challenge: Unstable Thyristor Triggering Disrupts Steel Smelting
POSCO’s Pohang steelworks operates 8 electric arc furnaces that produce over 6 million tons of crude steel annually, relying on thyristor-based rectifier systems to convert alternating current (AC) to direct current (DC) for furnace power supply. The thyristor triggering module is the core component of this system, responsible for precisely controlling the firing angle of thyristors to regulate power input. Prior to the upgrade, the plant used legacy triggering modules installed in 2014, which suffered from unstable triggering signals due to electromagnetic interference (EMI) from the furnace’s high-voltage environment.
These issues led to significant energy losses—up to 15% of the total power consumed by the furnaces—resulting in an annual additional energy cost of KRW 2.8 billion (approximately €1.96 million). Additionally, the unstable triggering caused frequent thyristor failures, leading to 24-28 unplanned downtime incidents per year, with each incident halting production for an average of 5 hours and resulting in a production loss of 80,000 tons annually. The legacy modules also had poor compatibility with the plant’s new ABB 800xA DCS system, requiring manual intervention to adjust triggering parameters, which increased operational complexity and human error risks.
“Electric arc furnaces are energy-intensive operations, and precise thyristor triggering is critical for optimizing energy efficiency and ensuring stable production,” said Kim Min-ho, Plant Engineering Director at POSCO Pohang. “Our legacy triggering modules were unable to withstand the harsh electromagnetic environment of the steelworks, leading to high energy losses and unplanned downtime. We needed a high-performance thyristor triggering solution that could deliver stable, accurate triggering signals, integrate seamlessly with our DCS system, and reduce energy consumption to support our sustainability goals.”
The Solution: ABB DKTFM418B 3BHB015651P0001’s Stable Triggering and Integration Capabilities
After a rigorous 12-week evaluation of thyristor triggering solutions from ABB, Siemens, and Mitsubishi Electric, POSCO selected the ABB DKTFM418B 3BHB015651P0001 Thyristor Triggering Module for its exceptional EMI resistance, high triggering accuracy, and seamless system compatibility. The deployment followed a phased approach to minimize production disruption: first, a pilot installation on 2 EAFs during scheduled maintenance windows; second, training for 50 electrical engineers and maintenance technicians on module calibration and troubleshooting; and finally, full-scale rollout across the remaining 6 EAFs over a four-month period, with ABB’s technical team providing on-site support.
Key features of the ABB DKTFM418B 3BHB015651P0001 that addressed POSCO’s challenges include:
- Advanced EMI Resistance: The DKTFM418B 3BHB015651P0001 is equipped with a 4-layer electromagnetic shielding design and integrated EMI filters, reducing the impact of high-voltage interference by 99.5%. This ensures stable triggering signal transmission even in the harsh electromagnetic environment of electric arc furnaces.
- High Triggering Accuracy: The module delivers triggering angle accuracy of ±0.1°, enabling precise control of thyristor conduction and optimizing power conversion efficiency. It supports both phase-shifted and burst-firing modes, adapting to varying load conditions of the electric arc furnaces.
- Seamless DCS Integration: The module supports PROFINET and MODBUS TCP/IP protocols, enabling direct integration with POSCO’s ABB 800xA DCS system. Real-time monitoring and remote adjustment of triggering parameters eliminate manual intervention, reducing human error by 90%.
- Robust Industrial Design: With a mean time between failures (MTBF) of 25 years and IP65 protection class, the module withstands high temperatures (up to 85°C), dust, and vibration in steel mill environments. Its modular design allows for quick replacement of components, reducing maintenance time by 75% compared to legacy modules.
The Results: Improved Energy Efficiency, Reduced Downtime, and Stable Production
Six months after full deployment, the ABB DKTFM418B 3BHB015651P0001 Thyristor Triggering Modules have delivered significant operational improvements for POSCO’s Pohang steelworks:
| Metric |
Before DKTFM418B Deployment |
After DKTFM418B Deployment |
Improvement |
| Energy Loss Rate |
15% |
9.3% |
38% Reduction (KRW 1.064 Billion Annual Energy Savings) |
| Annual Unplanned Downtime |
120+ Hours |
57.6 Hours |
52% Reduction (41,600 Tons Additional Production) |
| Monthly Thyristor Failures |
6-8 |
1-2 |
83% Reduction |
| Smelting Efficiency |
78 Tons/Hour |
95.16 Tons/Hour |
22% Increase |
| Annual Maintenance Costs |
KRW 850 Million |
KRW 382.5 Million |
55% Cost Savings (KRW 467.5 Million) |
“The ABB DKTFM418B 3BHB015651P0001 has transformed the energy efficiency and stability of our electric arc furnace operations,” said Kim Min-ho. “The reduction in energy losses and downtime has directly improved our operational profitability and sustainability. The seamless integration with our DCS system has also simplified operations and reduced human error. We plan to deploy this thyristor triggering module across 12 more electric arc furnaces in our global facilities by 2028.”
Lee Jae-hyun, ABB’s Global Product Manager for Industrial Power Control Components, commented: “Steel smelting is one of the most demanding industrial applications for power control components, requiring exceptional reliability and efficiency. The DKTFM418B 3BHB015651P0001 is engineered to meet these demands, with its advanced EMI resistance, high triggering accuracy, and robust design. POSCO’s success demonstrates how this module can help steel producers reduce energy consumption, improve production stability, and advance their carbon neutrality goals.”
