Transformer Core: Essential Things You Must Know
The coil winds on separate limbs on the transformer limb which acts as a magnetic circuit for transformers to reverse the current flow through the iron core known as the transformer core. The AC voltage is transformed through the transformer. This consists of a two- or more- core. The alternating voltage on one of the coils is applied. The current moving through it allows the magnetic flux in the core to change over time. This flow pierces all of the windings. This flow penetrates all the windings.
This flow penetrates all the windings and, according to the law of electromagnetic induction, induces an EMF in them. Depending on the ratio of the number of turns in the coils, the initial voltage in the secondary winding increases or decreases in comparison with the applied voltage.
A more effective voltage transformation allows the core to reduce scattering losses. An alternating magnetic field greatly affects the center of the transformer. This includes eddy currents. The magnetic circuit is also heated, which leads to loss of energy. Cores are made of steel, in which the reversal in magnetization often results in pointless energy consumption.
The important thing about the transformer is the component that is working. It’s made up of windings and a circuit magnet. Windings are wrapped in a core of metal. Aluminum or copper wire is also used for winding. Voltage is transmitted to primary winding from the network. The voltage difference at the input and output of the transformer depends on the difference in the number of turns of the windings.
What are the roles of the transformer core?
The transformer core is responsible for minimizing the loss of hysteresis in any transformer type that occurs when operating in the Alternating current state.
Minimizing the loss resulting from eddy currents produced in the transformer during operation. But this induced eddy current shifts as per magnetic flux produced in the iron core. While these eddy currents will lead to an increase in iron core temperature, their resistance will be improved for silicon-based cores in the process, reducing the loss caused by eddy currents when manufactured at the top magnetic core manufacturer in India.
Types of Transformer Core
Any transformer that has a magnetic core and has both main and secondary winding around the core can easily be categorized based on the transformer core design. This could be further defined as a transformer of the core type and shell-type. With a core style, transformer winding is often performed on the core while the core encircles around the main winding for shell type transformer.
Single and three-phase are the best examples of core type transformers. As of now, they have winding encircled around the core of the transformer which has two and three limbs respectively. The major disadvantage of such type as the magnetic flux produced in the primary circuit doesn’t always link to the second part since some amount of magnetic flux is being lost on the pathway itself due to leakages. However, core types are considered to be less efficient as a comparison to the shell type transformer since the flux loss is more in core type. But due to its maintenance, convenient core type transformers are more preferred for heavy power transformers. In case of any accident or malfunctioning winds can be easily removed from the outer and replaced easily.
However, in both types of cores, their cores are made of sheets of varying thicknesses up to 0.5 mm of electric steel core lamination, as they are rolled along in the direction of magnetic flux flow for core form construction and stacked in shell-style cores layers. Furthermore, the lamination for both types of transformer cores is always coated with a magnetic insulating layer to prevent eddy currents forming.
But Before Let Us Know Why Transformers Core is Laminated
The core of the transformer is being designed as per the specification to ensure that no current flows through it. There is still, however, a magnetic flow enclosed in the form of a circular loop that can be altered by changing the strength of the magnetic field used to flow the current called Eddy current.
Laminated cores are used for effective transfer of energy from secondary to primary in order to prevent significant losses.
Eddy currents are eliminated by reducing them with a laminated core resulting from the transformer heating and loss of hysteresis.
These are thus much more effective in operation compared to the solid iron core, as the laminate itself represents stacks of electrical steel sheets. This makes the laminated core slightly more resistant to eddy current than the laminated core. This prevents core heating and makes it much more structurally efficient.
On what parameters transformer cores being decided?
The transformer’s core shape is decided based on the parameters of the transformer ranking. For the lower transformer, a square in shape for that center is often specified. The winding is calculated accordingly. They also have an extremely low current capacity and are very cost-effective in scale.
Whereas heavy transformers have a larger core carrying the greater amount of current that passes through it. When it comes to conductor shape, the cylindrical-shaped winding is used with the copper conductor for large-rated transformers as opposed to the square that can not be formed or bent. There has been a large number of huge gaps left after winding the main transformer main which is filled in stepped cross-section. This cross-section type may have one or more multi-stepped laminated cores.
Here is a youtube video that describes the basics of core transformer. Also core cutting and core building process.