Our company is the leading production enterprise of electric furnace transformer in China and the leading drafting enterprise of all national standards for electric furnace transformer. Since the establishment of the factory, our company has been taking electric arc furnace transformer as the leading product. Through the design and manufacture of 0.5 tons of electric arc furnace transformer for steel furnaces from the 1960s to the design and manufacture of 220 tons of electric arc furnace transformer in 2010, the whole process has experienced the gradual improvement of electric arc furnace transformers for domestic steel furnaces, and formulated and revised the national standard for electric arc furnace transformers. Especially since the reform and opening up, it has absorbed the advanced technology and experience of foreign electric arc furnace transformers, and designed and manufactured electric furnace transformers with ultra-high power, high voltage and high impedance for long arc smelting, which has played a role in promoting the technological progress of the domestic smelting industry. Electric arc furnace transformer gradually developed from HSSP-1200/10 (before 1960), It has experienced HSSP-4200/10(before 1970), HSSP-7200/10(before 1980), HSSPZ-250/35 (1984), HSSPZ-400/35 (2000), HSSPZ-63000/35(2006), HSSPZ-900 00/35(2007), HSSPZ-14000/35 (2010) development process, since 1990, for domestic and foreign users supporting the supply of nearly 460 electric arc furnace transformers, including 63000kVA capacity of more than 30 products online operation, Including exports to Indonesia, Iran, Russia and other countries, the product runs well. Among them, the ultra-high power electric arc furnace transformer HSSPZ-90000/35 and the ladle refining furnace transformer HBSSPZ-45000/35 were also awarded the national scientific and technological achievements transformation certificate. The parameters of electric arc furnace transformer produced by our company have reached the international advanced level.
Electric arc furnace transformer is a representative kind of electric furnace transformer, and its short circuit and harmonic impact during operation are more frequent and intense than other kinds of transformers, so for electric arc furnace transformer, high requirements are put forward in design calculation, structural form, production process and test.
In order to enhance the ability of winding to withstand short circuit, concentric structure is adopted for large transformers, and self-adhesive commutation wires are preferred for winding wires, which greatly enhances the ability of transformer to withstand short circuit and reduces the winding eddy current loss and stray loss. The main longitudinal insulation margin of EAF transformer is increased to improve its safety factor of overvoltage shock during operation.
In the manufacturing process of electric arc furnace transformer, advanced structure is adopted to reduce the loss of empty load and enhance the impact resistance. For example, multi-step lap structure is adopted in the core, full oblique slot non-hole binding structure, and shear burr is strictly controlled. At the same time, advanced core stacking and turning table, no prestacking yoke iron and other technological measures are adopted. The grain orientation characteristics of the cold-tied silicon steel sheet are fully guaranteed, and the no-load loss of the transformer is effectively reduced. The low voltage winding adopts the dipping process to enhance its stability. During the transformer assembly, the "zero margin" between the winding and the core and between the winding and the winding is ensured through the adjustment of the stay, so as to enhance the mechanical strength of the winding and the ability to withstand short circuit. The body is completed in a completely closed constant temperature and constant pressure purification room, which meets the cleaning requirements and constant temperature requirements of 220kV products, ensuring the cleanliness and dryness of the body. At the same time, imported kerosene vapor phase drying equipment is used to make the cleanliness of the product better. The lower plate and the upper plate are all made of electrician laminated paperboard with high mechanical strength and electrical properties. The steel clamp and the steel nail have enough strength, choose the press bowl made of paper pulp insulation, and rationally arrange the position of the support pad, brace and press nail, so that the stress of the winding is relatively balanced, and improve the stability of the body. The body adopts the whole set constant pressure drying process to shorten the assembly time of the body. To ensure that the center of each winding is the same, so that the force of each winding is uniform, so as to improve the ability of each winding to withstand short circuit. In addition, the body and the fuel tank and the cover adopt six-way positioning measures to ensure the stability of the transformer during transportation, so that the transformer can be directly in place on the site, and the no-lifting core structure is realized, which provides great convenience for the site installation.
After the overall assembly of the transformer is completed, the oil pressure test is carried out to check the leakage points, and all the leakage points are eliminated before the transformer leaves the factory to ensure that there will be no leakage on the site. And the transformer in accordance with the national standard for all the tests, so that every transformer factory is excellent products.
Our company is a domestic manufacturer of electric arc furnace transformer with primary side of 66kV and above, and can be designed into three side breaking, direct drop type electric arc furnace transformer. The main advantage of this structure product is to solve the problem of frequent power outage of arc furnace and short life of circuit breaker, the transformer can operate the electric furnace under the condition of continuous power on the primary side, reduce the operation times of high voltage circuit breaker, reduce the operating cost caused by frequent replacement of expensive high voltage circuit breaker, and improve the production efficiency of steelmaking system.
Our company in the electric arc furnace transformer technology innovation at the same time, summed up and applied the following patented technology: Electric furnace transformer water-cooled secondary outlet device (ZL 2008 2 0072185.7), electric furnace transformer inner sealing Angle three-phase single outlet box outlet structure (ZL 2010 2 0510450.2), electric furnace transformer inner sealing Angle multi-group water cooling pipe outlet structure (ZL 2010 2 0510439.6), electric furnace transformer copper bar grounding structure (ZL 2010 2 0510455.5), electric furnace transformer low voltage outlet copper bar high and low staggered arrangement structure (ZL 2010 2 0510502.6), electric furnace transformer control cable bridge (ZL 2012 2 0174554.X), low voltage cold pressure connection structure of electric furnace transformer (ZL 2011 2 0197865.3), fixed frame for spiral plate strong oil-water cooler of electric furnace transformer (ZL 2012 2 0174595.9), parallel connection structure of low voltage winding of electric furnace transformer "8" (ZL 2010 2 0510480.3), unequal-turn spiral coil structure of electric furnace transformer (ZL 2011 2 0197738.3), etc.