Transformers are electrical machines which play a very important role in a building’s power system. They’re basically designed to modify any alternating current voltage via electromagnetic induction.
If you have a building, or perhaps a facility that deals with manufacturing, then there’s no doubt you have a demand for a constant supply of electricity. Along with this comes the need to deal with voltage instabilities as well as malfunctions on some machines because of voltage problems.
This is where a transformer comes in. It’s basically a solution for fixing such glitches. However, there can be cases where a transformer can perform inefficiently due to poor design – a case that could have been avoided if such design issues are addressed beforehand.
Fortunately, we at NY Engineers specialize in such field. With our transformer 3D design and modeling services, we’ll be able to come up with a foolproof and custom design for your transformer, allowing you to have it manufactured in accordance with your specifications.
With branches within several locations throughout the US, you can easily get in touch with us, whether you’re from Chicago, New York, New Jersey, etc.
Types of Transformers
By knowing the different types of transformers, you will be able to determine which among them is the most suitable for your facility. Also, by telling us your desired type of transformer, we will be able to know how we can proceed with your design.
Keep in mind that transformers are categorized based on their classifications which are as follows:
Transformers are classified as either step-up or step-down based on their voltage levels. These transformers are considered the most widely used type across all applications. The important thing you should remember is that there won’t be any difference in both primary and secondary power between the two.
A step-up transformer, as the name suggests, converts low voltage, high current AC to a high voltage, low AC system. This is achieved by increasing the coil turns on the secondary windings than on the primary winding.
On the other hand, a step-down transformer transforms high voltage, low current AC to a low voltage, high current AC. As opposed to the step-up variant, this one has more coil turns on its primary winding than the secondary.
A normal transformer comes with two windings on two different sides. However, in an auto transformer, both primary and secondary windings are connected to each other. It’s basically a special type of transformer as the two windings are interconnected electrically and magnetically.
Compared to standard two-winding transformers, an auto transformer has lower initial rates. Aside from that, it also has smaller voltage drops and is far more efficient. However, it’s not safe for use on ordinary distribution circuits. The reason is that high-voltage primary circuits are directly connected to the secondary circuit.
Each type of transformer is designed for a specific function. That said, when it comes to its application, a transformer can be classified as follows:
- Power transformer – a power transformer is commonly large in size and is mainly used for high-power transfer applications, specifically in transmission networks with higher voltages. Since they’re designed to deliver 100% efficiency, they’re mainly used in transmission substations and generating stations.
- Measurement transformer – as the name implies, this type of transformer is used for measuring electrical quantity such as power, current, voltage, etc. It can be further classified as potential and current, with the former used for measuring voltage and the latter for measuring currents.
- Distribution transformer – this type of transformer is used to distribute power generated from power plants to industrial and domestic locations. Compared to the other transformer types, a distribution type only has around 50-70% efficiency and isn’t always fully loaded.
Core Medium Used
Transformers can be classified as air core and iron core depending on the core medium they’re using.
In an air core transformer, both windings are wound on a non-magnetic strip, and the linkage between them is through the air. Air core transformers have generally less mutual induction compared to iron core transformers. However, they’re able to reduce, even eliminate, current losses and hysteresis.
Meanwhile, an iron core transformer has both windings wound on iron plates with the linkage being made through iron. Thanks to iron’s magnetic properties, there is less reluctance to the linkage flux. Compared to air core transformers, iron core transformers have higher efficiency.
When it comes to the supply used, a transformer can either be single-phase or three-phase. A single phase transformer is basically the standard transformer which features a primary and secondary winding. Generally, it is used for increasing or decreasing secondary voltage.
Meanwhile, a three-phase transformer has three primary windings and three secondary windings both interconnected with each other.
In some applications, one three-phase transformer is ideal compared to three single-phase units since it can offer higher efficiency at a lower cost and can be installed in limited spaces. The problem, however, is that it’s way heavier to transport, in which case single phase thermometers are more preferred.
Components of a Transformer
Apart from the different types of transformers, we also take into account the different components that make up a transformer. This way, our team won’t miss any detail that should go into your transformer design.
To give you an idea, here are the most basic components of a transformer we thoroughly keep in mind:
The core is the one that serves to support the winding. Aside from that, it offers a low reluctance path to the magnetic flux. Generally, it’s made of a laminated soft iron core as a means of reducing eddy loss and hysteresis.
Another important component of a transformer is the winding. A standard transformer will have two winding sets which are insulated from one another. Each winding has several turns of copper conductors that are bundled together then connected in series.
A winding is classified based on the voltage range and the input and output supply. In terms of voltage range, a winding can either be high voltage or low voltage. In a high voltage classification, the winding is made of a copper conductor which is thinner compared to that of a low voltage classification. Meanwhile, a low voltage winding has thicker copper conductors and has fewer turns than its high voltage counterpart.
When it comes to the input and output supply classification, a winding can either be primary (input voltage is applied) or secondary (output voltage is applied).
Transformers normally use cardboard and insulating paper as a means of isolating both primary and secondary winding from each other as well as the transformer core. Another insulating material comes in the form of transformer oil. This type of insulating material works to add extra insulation and cool both the core and coil assembly.
The breather is a cylindrical container which contains silica gel. Once air passes through the gel, moisture is then absorbed by the silica crystals. Basically, the breather is responsible for maintaining moisture level inside a transformer. Moisture generally increases due to pressure changes within the conservator, mainly due to temperature variations that result in the contraction and expansion of the transformer oil.
Basically, the purpose of a breather is to prevent moisture from getting in contact with the oil as it can lead to poor paper insulation or even internal faults.
This component serves to conserve the insulating oil. It’s in the form of a metallic cylindrical drum which is located above the transformer. Its function is to let the oil expand and contract as temperature changes.
Cooling tubes are made for cooling the insulating oil by circulating it through the tubes in either a natural or forced process. In a natural circulation, cold oil will sink downward and gets circulated while hot oil rises to the top. Meanwhile, a forced circulation involves the use of a pump to circulate the oil.
The purpose of an explosion vent is to prevent the transformer from exploding by removing boiling oil in case of heavy internal faults.
A transformer’s output voltage may vary depending on its load and input voltage. In high load conditions, the voltage will decrease in the output terminal. On the other hand, it increases during off-load conditions. This is where the tap changer becomes necessary. Its main purpose is to balance the variations of the voltage.
A tap changer can be either on-load or off-load. An on-load variant balances the variation without having to isolate the transformer from the supply, whereas an off-load tap changer performs the tapping after successfully isolating the transformer.
Lastly, the Buchholz Relay serves to detect any fault that might occur within the transformer. It’s basically a relay which functions via the gases that are emitted once the insulating oil decomposes during internal faults. Despite its simple function, it’s a really vital safety device which detects and protects the transformer from any possible internal faults.