Current Transformer

The principle of current transformer is based on the principle of electromagnetic induction. A current transformer is composed of a closed iron core and winding. Its primary winding has very few turns and is connected in series with the line that needs to measure the current, so it often has all the current flowing through the line. The secondary winding has more turns and is connected in series with the measuring instrument and protection circuit. When the current transformer is in operation, its secondary circuit is always closed, so the impedance of the measuring instrument and protection circuit series coil is very small, and the working state of the current transformer is close to a short circuit. A current transformer is used to convert high primary current into low secondary current, and the secondary side must not be open circuited. Divided by voltage level, high voltage current transformers, medium voltage current transformers, and low voltage current transformers; According to the principle of current conversion, there are electromagnetic current transformers and electronic current transformers; Divided by purpose: measuring current transformers, protective current transformers; Divided by insulation medium: dry-type current transformer, cast type current transformer, oil immersed current transformer, gas insulated current transformer; Divided by installation method: through type current transformer, pillar type current transformer, bushing type current transformer, busbar type current transformer.