EMC Test and Rectification

1、 The conventional electromagnetic compatibility (EMC) testing items are as follows

1. Electrostatic discharge immunity: The release of a large amount of electrostatic charges can instantly generate high voltages ranging from thousands to tens of thousands of volts, which can easily damage the internal circuits of electronic products. The ability of testing equipment to resist electrostatic discharge interference, the ability to resist electrostatic discharge interference, and the ability of testing equipment to resist electrostatic discharge interference.

2. Radio frequency radiation immunity: By simulating a certain intensity of electromagnetic radiation environment, the adaptability of the radio frequency radiation electromagnetic field immunity of civilian equipment is assessed, and the ability of the testing equipment to resist electromagnetic radiation interference, the ability to resist electromagnetic radiation interference, and the ability of the testing equipment to resist electromagnetic radiation interference are tested.

3. Electric fast transient pulse group: Verify the immunity of electrical equipment to transient disturbances generated during transient switching processes (such as cutting off inductive load relay contact bounce), test the equipment's ability to resist pulse interference signals, resist pulse interference signals, and test the equipment's ability to resist pulse interference signals.

4. Surge impact immunity: Transient switching and lightning transients in power systems can cause rapid changes in voltage and current, resulting in overvoltage and overcurrent, leading to product damage. Test the ability of the equipment to resist surge current impact. Test the ability of the equipment to resist surge current impact.

5. RF conducted immunity: At low frequencies, the interconnection cables of the tested equipment are more likely to become antennas and receive electromagnetic fields than the tested equipment itself. Therefore, the low-frequency part is evaluated using conducted immunity testing methods. The ability of the testing equipment to resist electromagnetic interference signals propagated through wires is evaluated based on its ability to resist electromagnetic interference signals propagated through wires.

6. Power frequency magnetic field immunity: The power frequency magnetic field generated by the power frequency current in the conductor or other nearby devices (such as the leakage flux of transformers) can affect the reliable operation of electronic equipment or systems.

7. Pulse magnetic field test: Transient faults in low-voltage, medium voltage, and high-voltage power systems can generate pulse magnetic fields that affect the reliable operation of electronic equipment and systems.

8. Damping oscillation magnetic field: When the isolation switch of a high-voltage substation is in contact with the high-voltage busbar, it will generate a damping oscillation magnetic field, which will affect the reliable operation of electronic equipment and systems.

9. Voltage drop immunity: When there is a sudden significant change in the power grid, electrical facilities, or load, it can cause temporary voltage drops, short-term interruptions, and other phenomena in the low-voltage power grid.

10. Ringing wave immunity test: Ringing waves, as a transient oscillation wave of a single shock, are mainly caused by lightning strikes or power load switching, and can be used to evaluate the tolerance of electronic devices to ringing waves.

11. Damping oscillation wave immunity: Damping oscillation waves are transient pulse groups of damping oscillations, mainly caused by reignition due to switch operations in power plants, high and medium voltage substations, and heavy industrial equipment. They can be used to evaluate the tolerance of electronic devices to damping oscillation waves.

12. Radiation emission test: testing the radiation interference intensity of electronic, electrical equipment or systems to the outside world during normal operation, electromagnetic emission waves generated by the source or interface equipment, random broadband radiation interference outside the working frequency propagated and measured by space.

13. Conducted emission test: It mainly refers to an electromagnetic phenomenon in which the voltage or current inside the system is transmitted through signal cables, power lines, or ground wires and becomes a source of interference for other systems or equipment. It is also commonly known as disturbance voltage test.

14. Harmonic current test: The input voltage of the equipment is a sine wave. When the input load of this voltage is a nonlinear circuit, the input current will be distorted, that is, the input current is not a sine wave. According to Fourier transform, non sine signals will have harmonics in the frequency domain. These harmonic currents will reduce the efficiency of the equipment power supply and pollute the power grid. The basic method to solve harmonic currents is to add a power factor correction circuit or change the existing PFC circuit in the original power supply circuit.

15. Voltage sag test: Voltage sag and short-term interruption are caused by faults in the power grid, power facilities, or sudden large changes in load. Voltage variation is caused by continuous changes in the load connected to the power grid. If the EUT cannot respond promptly to changes in power supply voltage, it may cause malfunctions. The ability of testing equipment to resist voltage drops, the ability to resist voltage drops, and the ability of testing equipment to resist voltage drops.

16. Voltage flicker test: To ensure that the product does not cause excessive flicker effects (light flicker) on the lighting equipment connected to it.