Many customers and industry practitioners often wonder why the cores of mainstream power equipment such as distribution transformer, three phase oil immersed transformer,dry type transformer are meticulously assembled with stacked silicon steel sheets, instead of adopting a single solid silicon steel block. On the surface, a one-piece solid core seems more convenient, saving production steps and simplifying processing procedures. However, this seemingly redundant lamination design is a mature and essential industrial engineering principle in the transformer manufacturing industry, which fundamentally guarantees the operational stability, energy efficiency, heat dissipation performance and long-term service life of all types of power transformers.
All power transformers operate based on the fundamental principle of electromagnetic induction. Once the transformer is energized and put into operation, it will continuously generate an alternating magnetic field that penetrates the entire iron core structure. In accordance with basic electromagnetic physical principles, the constantly changing magnetic flux will induce closed circulating currents inside the metal material of the transformer core, and these internal circulating currents are professionally defined as eddy currents. Eddy current loss is recognized as one of the most critical energy losses during transformer daily operation. Excessive eddy currents will not only cause serious electric energy waste and reduce the overall working efficiency of the equipment, but also lead to continuous abnormal heat accumulation on the transformer core.
We can use a vivid water flow analogy to help everyone fully understand the hazards of eddy current loss. If we regard the entire transformer core as a complete open water area, the eddy currents generated inside the core are equivalent to powerful swirling water flows. If manufacturers adopt an integrated solid silicon steel core, these eddy currents will circulate freely without any obstruction, forming large-scale intense whirlpools inside the core. Translated into actual equipment operation, this will produce extremely high eddy current loss in a short time. The core temperature will rise sharply, causing continuous overheating of the transformer body. In extreme working conditions, the equipment will suffer performance degradation, operational malfunction, and even core burnout and equipment scrapping, bringing huge hidden dangers to the safety of power distribution systems and industrial power supply.
The innovative structural design of stacked insulated silicon steel sheets perfectly solves the pain point of excessive eddy current loss in solid cores. The tightly laminated silicon steel sheets with insulating layers separate the original integral core structure into dozens of independent narrow magnetic conduction and current conduction channels. Just like dividing a wide and open water area into countless narrow and isolated waterways, the powerful eddy current flow will be evenly dispersed and effectively blocked. This structural optimization greatly suppresses the formation and circulation of large eddy currents, significantly reduces core energy loss, controls the core heat generation within a reasonable range, and realizes stable and efficient operation of the transformer for a long time.
As a professional and experienced transformer manufacturer, Zhejiang Hengli Electrical always focuses on refined manufacturing and technical optimization. We strictly implement precise lamination craftsmanship for every three phase oil immersed transformer and dry type transformer we produce. All silicon steel materials are strictly screened for quality, and each sheet is coated with high-performance insulating material to ensure uniform lamination gap and stable insulation performance. This rigorous manufacturing process effectively reduces no-load loss and heat generation for our distribution transformer series products, greatly improves equipment energy utilization efficiency, and effectively extends the overall service life of power transformers. It is these seemingly cumbersome and refined production processes that interpret the ingenuity of industrial manufacturing, bringing customers safer, more efficient and more durable power transmission and distribution equipment solutions.
