Electro Magnetic Compatibility Analysis of Signal Interference on Ultra-Low Power Four-Level ECT

To enhance the electromagnetic protection performance of ultra-low power Electronic Current Transformer (ECT), a damping oscillatory wave (DOW) disturbance test is conducted on it. A method for generating parallel resonant DOWs is proposed, which involves two-stage following and amplification of the initial waveform, enabling a maximum voltage of over 12V. Finally, considering the characteristics of the output signal from the four-level encoding module of ultra-low power ECT, electromagnetic interference countermeasures combining Transient Voltage Suppressor diodes with RC low-pass filters are proposed. Experimental results show that the four-level encoding module is extremely sensitive to voltage fluctuations due to the nonlinear relationship between the voltage and current of the LED. The normal operation of the four-level encoding module can be ensured through anti-interference measures.