You might look at the power lines and figure that a power line is a power line and when it gets to wherever it's going, it's going to be the same voltage as it is when it gets to your house and all the things that are going to use that power are going to be just like the ones at your house. However, that's not the way that it works. Different power lines carry different voltages of power. And different machines are going to have to use different voltages. But, that can lead to some issues. There has to be a way to deal with all those differing voltages and power needs. That's where transformers come in.
Transformers are devices which will let the given voltage of any power source to go up or down. That means that a high voltage line can come into a factory, via a transformer, or more as necessary, and turn into the proper voltage. That same power source could feed the factory, with a main transformer that brings the power down to a usable voltage, and then different pieces of equipment will have their own transformers so that they can have more or less voltage, as needed. But how do transformers work? It's not like they can wave a magical wand to do it.
How They Work
While the transformers aren't magic, some people may feel like they are. What they are, though, is a product of electromagnetics. In the transformer, there are going to be two posts that are close to each other but aren't touching. Those posts are going to have multiple wraps of a wire around them. That turns them into the electromagnet and lets them transform the power from one voltage level to another. The way that they work is that the incoming voltage is associated with the first post. It will have a certain number of wraps that let it be that voltage. The second post, if the voltage has to go down, will have fewer wraps. For example, if the incoming power is 60 volts and it needs to be at 30 volts, then the second post would have half as many wraps around it. Likewise, if the power has to go from 60 to 120, then the second post would have twice as many wraps.
Industrial transformers let the various power lines and pieces of equipment get used in the voltages they need to be in.