Introduction: **
Current Transformer (Current Transformer or CT)
. Structure and function:
. Types of current transformers:
- Measuring CTs: used to measure normal load currents in power systems.
- Protective CTs: designed to protect against fault currents and abnormal conditions such as overload or short circuit.
- Accurate CTs: for
testing and calibrating CTs:
testing and calibrating CTs is necessary to ensure the accuracy and correctness of their operation. The calibration process includes several steps:
- Conversion ratio test: making sure that the current transformer conversion ratio matches its nominal values.
- Accuracy test: checking the accuracy of the current transformer measurement in different load conditions.
- Magnetic current test: assessment of magnetic saturation and its effect on measurement accuracy.

. Tools used in testing and calibration:
Different devices are used to perform tests and calibration of CTs, including:
- CT test devices:
- **Microohmmeters:*
- Generators Detailed flow: