To avoid magnetization of a current transducer, the following measures can be taken:
1. Prevent Overload Currents:
- Avoid High Overload Currents: Magnetization occurs when the transducer’s core is exposed to excessive currents that can saturate the magnetic circuit. To minimize this, ensure that the current transducer is not subjected to currents exceeding its rated capacity. Proper protective devices, such as fuses or circuit breakers, should be in place to limit high overload currents.
2. Ensure Continuous Power Supply:
- Maintain Power Supply: Interruption or a lack of power supply to the transducer can result in an undesirable magnetic offset. To prevent this, ensure a reliable power supply and avoid unnecessary interruptions.
3. Use a Transducer with Lower Magnetic Remanence:
- Select Materials with Lower Residual Flux: Some magnetic materials used in transducers have higher residual flux (magnetic remanence), leading to higher magnetic offsets. Choosing transducers made from materials with low remanence can reduce the likelihood of magnetization.
4. Demagnetization (Degaussing) Process:
- Perform Periodic Demagnetization: If magnetization occurs, a degauss cycle can be used to restore the transducer’s core to its initial state. This involves applying a low-frequency AC current through the core, gradually decreasing the amplitude to remove residual magnetization. This process should be performed after any overload or interruption event.
- Reversal of Primary Current: Another method of demagnetization is to apply a reverse current to the primary winding, effectively neutralizing the magnetic offset.
5. Regular Monitoring:
- Monitor for Magnetic Saturation: Regularly checking the transducer’s performance can help in detecting any offsets early. If a magnetic offset is detected, performing demagnetization can restore accuracy and prevent long-term performance degradation.
By taking these precautions, magnetization of the current transducer can be minimized or avoided, ensuring accurate and stable performance over time.