Current Transformer

Current transformer (CT) is a widely used power measurement sensor in power systems, which is used to measure the current in high voltage (AC) circuits. Its main function is to convert a large current into a small current to facilitate measurement and protection of the circuit. It can provide the function of isolating and protecting the circuit

Before installing a CT, the measurement is performed directly on the circuit, but this often leads to circuit overload and damage, as well as potential safety hazards. To avoid this situation, CT is used to monitor the current.

There are many different types of current transformers, including open type, closed type, pole type, and window type CTs, which have their respective advantages, disadvantages, and applicable conditions. However, they all work on the same principle

The winding of the CT is wrapped in an iron core and can be accessed by installing clips or perforations. When there is current flowing through the circuit, the current will generate electromagnetic induction inside the CT winding. This will cause a secondary current to be generated at the CT output, and the magnitude of the secondary current is proportional to the input current.

When using current transformer, close attention needs to be paid to accuracy and inductance. The accuracy of a CT depends on its scale and phase error. Inductance is also one of the factors that need to be considered, because current transformer not only consumes a certain amount of electrical power, but also produces magnetic interference.

Current transformer is an important component of power system, which provides protection and measurement functions for circuits, helping to ensure power safety and efficiency. Many factors need to be considered when selecting CT, such as accuracy, inductance, type, and so on.