The most traditional transformers include windings that are classified as primary, secondary and tertiary and the current that flows between these windings has to depend on the fluidity. The passage of current through these wires is guided by the influence of magnetic cores that serve as the free passage of power within the transformer. The magnetic field in the magnetic core attracts flux in the transformer to the point of circulation because the core has high magnetic permeability and it serves as a permanent magnet with a substantial amount of ferromagnetic field present.
Magnetic cores are made of such different materials. Let us discuss some other types of elements which do compose magnetic properties just like their ferromagnetic metals.
Iron in solid form retains one of the best core values to be an excellent source of magnetic flux that retains high magnetic fields without making the iron resilient to further magnetization. Transformers must retain proper flux but due to producing whirls of current, solid iron is a bad core to regulate transformer power supply because its magnetic field reverberates large current value and generates heats at high frequency.
An optimum performance value, silicon steel is highly resistive to current and does not saturate at high flux density, thus maintaining high magnet core value. Because silicon steel has high permeability and does not offer many losses, it can be used in different components that require performance precision. It has a low core loss. Silicon steel is rather used in laminated cores made of thin silicon strips of steel.
Carbonyl iron is also known as RF cores but has lower permeability. This metal adapts to different temperatures but is stable at magnetic flux levels. It has tiny micrometer-sized iron spheres coated with a thin insulating layer to control high degrees of flux.
Amorphous steel is made of many thin layers of magnetic tapes strapped over one another to reduce eddy current flow. These tapes control current loss and give uniformity but their magnetic core nature is better than other magnetic cores and hence even at high temperatures, these tape like cores are used in high-efficiency transformers that operate at medium frequencies. But it cannot be used in motors due to brittleness.
Amorphous or vitreous metals have good electrical conductivity. They have the glassy appearance but are non-crystalline in nature. Their atomic structure is loosely structured. Transformer magnetic core is best suited for amorphous metals as they have low conductivity points that help it to reduce eddy flux voltages and hence they work as highly efficient materials in high-performance transformers. The low conductivity of these materials helps to reduce eddy currents. They also are prone to low hysteresis loss because of the high response to magnetic field.
With a combination of iron oxide and multiple metals, we have ferrite ceramics that meet up different electrical requirements. Other metallic elements like barium, manganese, nickel and zinc can be added to iron or oxide to make ferrite ceramics and have a strong attraction towards a magnet. There are two ferrites, hard ferrites and soft ferrites. Soft ferrites are suited to making high-frequency inductors and transformers.
Laminated Magnetic Cores
Laminated magnetic cores are made up of thin square sheets of iron coated with an insulating layer which are stacked one over other to lie parallel to the lines of flux. The layers of each sheet prevent any eddy current passing through which then flows through the narrow loops within each single lamination layer. This technique is best for current from flowing to a very low level and controls flux. Such narrow laminations also reduce power losses. Precisely, eddy current can be better controlled if the laminations are very thin.
Transformer manufacturing companies know which core will suit them most. An electrical engineer can tell you which core to use when you need to make a transformer. With the Indian industry expected to invest 1200K in the power sector, boosting its transformer manufacturing capacity is one such plan. Hence, leading transformer markers in India like Servo Star will contribute a lot to the domestic consumption in India by making customized transformers from their various in-house products and helping you choose the best product for your requirement.