Zero Sequence CT

Zero Sequence Current Transformer (ZCT) is an electronic device used to measure zero sequence current in three-phase AC circuits. Its main function is to detect the zero sequence current in the circuit in order to timely detect and resolve electrical faults.

The working principle of ZCT is based on Faraday’s law of electromagnetic induction. When an alternating current passes through the coil, an alternating magnetic field is generated in the coil and an alternating voltage is induced at the other end of the coil. For a zero sequence current transformer, because it only measures the zero sequence current in the circuit, it typically passes a three-phase cable through the middle of an annular iron core in order to sense the annular magnetic field.

Zero sequence current transformers are widely used in power systems, such as high-voltage substations, distribution transformers, and power plants. Specific applications include:

Ground ground protection: In power systems, the ground may be short-circuited to the circuit. At this time, the zero sequence current transformer can detect the increased zero sequence current in the circuit, thereby triggering ground grounding protection in a timely manner.

Fault detection: Faults often occur in power systems, such as cable short circuits, equipment damage, etc. By detecting the zero sequence current in the circuit, faults can be detected in a timely manner