Inhibition of electromagnetic interference in control system based on DSP of high-power TEA CO2 laser

The strong electromagnetic interference (EMI) generated in high-power TEA CO2 laser system mainly comes from main discharge circuit, pulse spark switch and power supply. Such strong EMI causes great damage and interference to the control system based on DSP. In this paper, we present the interference sources and their distribution and propose the methods of anti-interference. Measures for hardware design include weakening transient ground potential difference by using equipotential lines between devices, using signal isolation interface to inhibit the transient ground potential interference, and rational layout, shielding and filtering to the control system. And methods for software design include range-limited filter, self-diagnosis and self-repair for the critical data and anti-interference during abnormal reset. The EMI has been inhibited effectively by the anti-interference method proposed above. The result shows that: the software anti-interference method is as important as the hardware anti-interference method for the control system in a complex environment of strong EMI.