How do three-phase current transformers work?

Update time : 2024-01-25 14:49:39

Some knowledge about HEYI three-phase current transformer

Three-phase current transformers are similar to single-phase current transformers, but they are suitable for three-phase power systems and are capable of measuring current in three phases. Common in power systems is three-phase alternating current, in which there are three phases in the transformer, usually labeled A phase, B phase and C phase. Three-phase current transformers are used to measure the current in these three phases. In order to measure the current of each phase, a three-phase current transformer usually consists of three single-phase current transformers, each transformer is responsible for measuring the current of one phase. These three transformers can be installed in a power system in a specific arrangement. Our common arrangements include star connection and delta connection. The working principle of a three-phase current transformer is similar to that of a single mutual inductor. When current is passed through the wires of the primary winding, a magnetic field is created in the secondary winding of the transformer. This magnetic field is induced into the secondary winding, producing an induced electromotive force. Since there are phase differences in a three-phase system, the phase relationship of the currents measured by each transformer must also be considered. The measurement results need to be properly processed to reflect the relative relationship between the phases in the power system. Like single mutual inductors, three-phase current transformers also have ratios that express the relationship between the primary winding current and the secondary winding current. In general, the three-phase current transformer uses the principle of electromagnetic induction to convert the three-phase current into a smaller current that can be measured and processed, thereby playing the role of measurement and protection in the three-phase power system. Different arrangements and phase processing methods can be adapted to different types of three-phase systems.

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