Inverter on the signal interference of plc and stepper motor - News - Global IC Trade Starts Here.

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In industrial equipment, various components such as inverters, AC contactors, relays, and switching power supplies can generate electromagnetic interference (EMI). This interference can significantly impact the performance of PLCs and stepping motors. For example, the harmonics from an inverter can cause flickering on the PLC display, lead to key failures, or result in abnormal input/output signals. Similarly, EMI from the inverter can cause a stepping motor to vibrate or lose steps. To address these issues, consider the following solutions: 1. Use high-quality inverters with better noise suppression. If possible, choose a well-known brand and ensure it has a metal enclosure for better shielding. 2. Add ferrite cores to control lines and include a "run/stop" signal alongside pulse signals for the stepping motor. 3. Avoid running signal lines parallel to power lines to reduce crosstalk and interference. 4. Lower the inverter's carrier frequency if possible, as higher frequencies tend to increase EMI. 5. Install output reactors, input filters, and output reactors at the inverter’s input and output ends to minimize harmonic distortion. 6. Ensure the inverter is properly grounded to prevent stray currents from causing problems. 7. Use signal isolators to break ground loops and protect sensitive circuits. 8. Shield the cables connecting the inverter to the motor to prevent signal degradation. 9. Construct the cabinet using steel plates to create a Faraday cage-like structure. Keep the PLC and inverter physically separated so that any electromagnetic waves are directed away from sensitive components. 10. Make sure all grounding connections are solid and reliable. The shielding layer of shielded cables should be grounded at one end only to avoid ground loops. 11. Avoid placing signal shielding cables parallel to inverter power lines to prevent coupling of interference. 12. Place ferrite rings on each line at the outlet end. These can be purchased from electronic stores, and the more turns you make through the ring, the more effective it becomes. 13. Adjust the inverter’s carrier frequency. If this doesn’t resolve the issue, reorganize the layout inside the electrical cabinet and optimize cable routing, as poor placement can worsen interference. 14. Apply ferrite cores to signal lines and reduce the inverter’s carrier frequency to suppress unwanted noise. 15. Install EMC filters and use a shielded enclosure for the inverter to further reduce EMI. 16. Check whether the inverter’s power and signal lines cross each other, as this can amplify interference. 17. Lower the inverter’s switching frequency (e.g., 4kHz, 8kHz, or 12kHz) to reduce high-frequency noise. 18. Always use shielded cables for the inverter to prevent interference from affecting other devices in the system. By implementing these measures, you can significantly reduce electromagnetic interference and improve the stability and reliability of your control systems.