In recent years, with the rapid development of power electronics technology, high-voltage variable frequency speed regulation technology has been increasingly widely applied in various industries, such as municipal water supply, power, petroleum, petrochemicals, cement, coal, and others. It can not only improve processes, extend equipment service life, and increase work efficiency, but most importantly, it can “save energy and reduce consumption.” In response to market demand, our company has developed H-class insulation system drive rectifier and multi-pulse rectifier transformers. The 18-pulse rectifier transformers produced by our company are matched with variable frequency drives from internationally renowned companies such as Siemens, ABB, and AB, as well as multi-pulse phase-shifting rectifier transformers matched with unit-series variable frequency drives from domestic well-known companies such as Leader Harvest and Hiconics. The single-machine 18-pulse dry-type rectifier transformer used for Angang No. 2 converter, as well as products matched with Rockwell (ROCKWELL) from Canada, have received high praise from users during on-site operation.

Product Features:

1.Superior Harmonic Interference Resistance

In the design, the magnetic flux density is reduced by 10% compared to power transformers, and the current density of conductors is lowered. Electrical shielding is added between high- and low-voltage coils, effectively reducing pollution from high-order harmonics on the valve side to the grid, while also preventing grid-side harmonics from being transmitted to the valve side and interfering with the control system.

2.High Overload Capacity

The insulation system of this dry-type rectifier transformer uses DuPont NOMEX® paper from the United States, which is a Class C insulation material with a heat resistance temperature of up to 220°C. When derated for use in Class H dry-type rectifier transformers, a series of measures are taken in electrical and mechanical performance to ensure overload requirements.

3.Excellent Mechanical Performance

The leakage magnetic field of the coils under short-circuit conditions is calculated for the dry-type rectifier transformer, and the coil structure is optimized to improve leakage magnetic field distribution, reduce axial mechanical force, increase the number of coil supports, reasonably enlarge the width of coil spacers, and install tensioning devices during winding to control coil tightness, thereby improving the stability of the transformer.

4.Prevention of Local Overheating

Through reasonable calculations, not only is the transformer efficiency improved, but local overheating caused by concentrated stray losses is avoided, effectively preventing local overheating.

5.Control of Temperature Rise

Considering the rolling process of steel, rectifier transformers are subject to long-term impact loads. When designing temperature rise, our company adopts a design 15K lower than the national standard. Considering harmonic components, the current density of conductors is selected 10% lower than ordinary power transformers. At the same time, the hottest spot temperature is controlled. Computer simulation is used to perform three-dimensional field stereoscopic demonstration and mapping of the leakage magnetic field distribution to avoid excessive concentration of leakage flux, making the difference between the hottest spot temperature on the valve side of the rectifier transformer coils and the average temperature of the windings lower than the 13 degrees specified in the national standard, reaching 10 degrees, thereby extending the service life of the rectifier transformer to a certain extent.