In the vast power system, the Current Transformer (CT) may not be very eye-catching, but it is an indispensable key device to ensure the stable operation of the power grid and the safety of power. As an electrical measuring device, the current transformer converts high current into low current through the principle of electromagnetic induction, which not only realizes the measurement and monitoring of current, but also bears the heavy responsibility of protecting circuits and instruments.

The working principle of the current transformer is based on Faraday's law of electromagnetic induction. When a large current in the main line flows through a turn (N1) of wire, a magnetic flux Φ is generated, which also acts on the coil on the secondary side (N2). Although the number of turns of the secondary coil is large, the current is small, thus realizing the value conversion of the current. This process seems simple, but it contains profound physical principles and technical challenges.

The current transformer plays multiple roles in the power system. It is an important tool for current measurement. In the current monitoring of large electrical equipment such as transformers, generators, and motors, current transformers can convert high-voltage and high-current signals into low-voltage and low-current signals that are easy to measure and process, ensuring the accuracy and reliability of current data.

Current transformers are key equipment for power system protection. When a power system fails, such as overload or short circuit, current transformers can quickly detect abnormal current signals and cut off the fault circuit through protection devices, thereby avoiding equipment damage and casualties. This rapid response capability provides a solid guarantee for the safe and stable operation of the power system.

Current transformers also play an important role in electric energy metering. Through current transformers, high current signals are converted into low current signals and input into the power meter together with voltage signals, realizing accurate and real-time monitoring of the electric energy consumption of various electrical equipment in the power system. This not only helps the refined management of power companies, but also promotes the rational use of energy and energy conservation and emission reduction.

With the development of the power system, current transformers are also facing new challenges and opportunities. On the one hand, with the construction of transmission lines and the increase in power load, the presence of DC components in the power system has affected the transmission characteristics of the current transformer, resulting in an increase in transmission errors. The research on the detection technology of the DC resistance performance of the current transformer has become an important topic at present. By establishing a CT core excitation characteristic model, the researchers derived the calculation formula for the transmission error of the CT under the influence of the DC component, and proposed a variety of current transformer DC resistance performance detection schemes, which provided strong support for the performance optimization of the current transformer.

On the other hand, with the rapid development of artificial intelligence technology, the integration of current transformers and intelligent technology has also become a new trend. By integrating sensors, communication technology and intelligent algorithms, current transformers can realize functions such as remote monitoring, fault warning and intelligent scheduling, further improving the intelligence level and operation efficiency of the power system.