At a certain steel plant 15,000 m³/h In the oxygen-generation project, products manufactured by Changsha Otto Automation Technology Co., Ltd. ATAF-H In this series, the medium- and high-voltage soft starter achieves successful load‑on‑start on the first attempt, delivering outstanding performance that ensures smooth starting of large motors while effectively safeguarding the safe and stable operation of both the power grid and the equipment. This successful implementation not only resolves the challenge of grid disturbances in the steel plant’s oxygen‑production project but also provides a replicable technical benchmark for similar operating conditions across the steel industry.

I. Project Background: Oxygen-enriched smelting has driven the demand for high-power motor startups.

With the widespread adoption of oxygen-enriched combustion technology in the ferrous metallurgy industry, steel enterprises’ demand for oxygen continues to rise. Oxygen-enriched combustion technology can enhance production capacity, reduce fuel consumption, and lower… NO ₓ 、 CO and CO ₂ Emissions comply with the national requirements for energy conservation and emissions reduction. To this end, the steel plant upgraded and renovated its existing oxygen-generation units. However, the inrush current generated during the startup of large motors poses a serious challenge to grid stability and equipment safety. Following extensive technical evaluations by experts, the solution ultimately selected was manufactured by Otto. ATAF-H The series‑type soft starter serves as the starting scheme.

II. Solution: ATAF-H Technological Breakthroughs in Soft-Start Devices for Motors

Otto ATAF-H The series of medium- and high-voltage soft starters is suitable for starting large and medium-sized medium- and high-voltage AC induction motors and medium- and high-voltage electrically excited synchronous machines. It employs a start-up method that gradually increases output voltage and frequency, enabling the motor to smoothly reach its rated speed and operating condition.

Its core technological features include:

1.  Starting current < rated current: By employing a wave‑by‑wave soft‑start technique, the starting current is consistently kept below the motor’s rated current, significantly reducing the demand on grid capacity compared with conventional reduced‑voltage soft‑start devices.

2.  Power factor > 0.95 : Input power factor at load > 20% It can be achieved at that time. 0.95 As described above, no auxiliary reactive power compensation device is required, and the motor delivers high‑quality sinusoidal voltage and current during startup.

3.  Rapid Response Platform: Based on High Speed ARM 、 DSP 、 FPGA The control platform is well-architected, ensuring rapid system response and reliable operation.

4.  Soft start: No‑impact startup to rated speed, effectively extending equipment life and maintenance intervals.

5.  Simulation‑based optimization design: Leveraging computer simulation techniques to optimize the spatial distribution of heat sources, and employing extreme‑condition analysis, high‑voltage finite element analysis, and topology optimization to refine the structural design.

III. Practical Application Results

In this project, ATAF-H The soft-start device successfully initiated the load in a single attempt. Actual operating data indicate that the startup process was smooth and stable, with grid disturbances kept to an extremely low level, thereby fully validating the device’s technical feasibility for high‑power motor start‑up applications.

From the perspective of power‑quality improvement, this device employs precise current control to keep the inrush current well below the motor’s rated current, thereby significantly reducing the demand on grid capacity.

IV. Industry Significance and Outlook

The successful implementation of this project has not only resolved the grid‑impact issue for a steel plant’s oxygen‑production facility but has also provided strong support to the enterprise. “ Dual Carbon ” The achievement of this goal has also provided a mature and reliable technical solution for the starting of large electric motors in energy-intensive industries such as steel, chemicals, and mining.