A method for determination of current control parameters avoiding voltage saturation and considering magnetic saturation for i ligb precision drive of a permanent magnetic synchronous motor

For use as a drive motor in a high precision NC machine tool feed axis, a permanent magnetic synchronous motor (PMSM) requires a highly responsive current control loop. Without consideration of the PMSM electromagnetic characteristics such as voltage saturation and magnetic saturation, the current control loop may be unstable. This paper proposes a method for determination of the PMSM current control parameters providing such high response, while avoiding voltage saturation by inverter output voltage constraint or declination of inductance by magnetic saturation. Experiments were done using two representative PMSMs alone and also using a machine tool. Testing confirmed that the proposed method is effective for achieving a highly responsive current control loop and making the cutting surface smoother.