How Does A Current Transformer Work?
A current transformer is a category of instrument transformer designed and manufactured to generate an alternating current in its second winding. This current is directly proportional to the current measured in its primary winding. At Midwest Current Transformer, we offer our customers high-voltage transformers to meet various industrial applications.
A current transformer only has one or a very few number of turns that consist of its primary winding. The primary winding may either consist of one single flat turn, a busbar conductor placed through a central hole, or heavy-duty coil wire wrapped around the core.
As a result of this arrangement, a current transformer is also called a series transformer. This is due to the fact that the primary winding, consisting of very few turns, operates in series with the conductor that transports current delivering a load.
However, the secondary winding may consist of a large number of coil turns wrapped around a laminated core that consists of low loss magnetic material. With the core consisting of a large cross-sectional area, the resulting magnetic flux density is on the low side and utilizes a significantly smaller quantity of cross-sectional area wire. The amount of wire used depends on the degree to which the current must be stepped down as it works to provide a constant current, separate of the connected load.
A current will be generated from the secondary winding flow into either a short circuit like into an ammeter, or into a resistive load until the voltage developed in the secondary is large enough to create a saturated core or precipitate failure as a result of disproportionate voltage breakdown.
The primary current operating in a current transformer is controlled by an external load and is not dependent on a secondary load current, unlike the voltage transformer. One ampere or five amperes for bigger primary current ratings often constitute the secondary current rating.