Strömtransformatorn

Strömtransformatorn, often translated as current transformer (CT), is a type of transformer used for measurement. Its primary purpose is to safely reproduce the current flowing in a high-voltage circuit in a much lower, measurable current in a secondary circuit. This allows instruments like ammeters and relays to be connected without being exposed to the high voltage and current. The CT has a primary winding, typically consisting of very few turns, that is connected in series with the circuit being measured. The secondary winding has many more turns and is connected to the measuring instrument. When alternating current flows through the primary winding, it induces a magnetic flux in the core, which in turn induces a current in the secondary winding. The ratio of the primary current to the secondary current is determined by the turns ratio of the windings. It is crucial that the secondary winding of a current transformer is never left open-circuited while the primary is energized. This is because an open secondary would result in a very high voltage appearing across the secondary terminals, potentially damaging the transformer and posing a safety hazard. Current transformers are essential components in electrical power systems for monitoring, protection, and control.