Electromagnetic Interference Issues in Numerical Control Machine Tools

With the rising of PWM carrier frequency, the fast swishing of IGBT produces more and more harm to motor drive system. Effective measures must be taken to suppress electromagnetic interference in order to ensure a reliable work of NC machine tools. Electromagnetic interference in numerical control machine tools are introduced at first. Common-mode voltage generated by voltage source PWM inverter and the essences of its adverse effects are investigated in the paper, and common-mode voltage reducing methods are also presented. In IGBT PWM inverter-induction motor system,the high dv/dt and di/dt due to the fast swishing of IGBT could bring serious EMI issues and common-mode voltage is a major source of adverse effects. Finally, the EMI suppressing methods are expounded.