In the field of high precision positioning control, the position servo system must be highly robust against disturbance torque. A Permanent Magnet Synchronous Motor (PMSM) has various torque ripple components that degrade control performance. A portion of the torque ripple is caused by the harmonic current. The torque ripple can be suppressed using a highly robust current control system. The remaining torque ripple is defined as the disturbance torque and is compensated for using a Disturbance OBserver (DOB). However, it is very difficult for a DOB to perform the appropriate compensation because it uses a low-pass filter to reduce noise. To obtain highly robust performance, this paper proposes a new position servo system using a disturbance torque hybrid observer and a current control system in the α-β stationary frame. In addition, this paper uses the torque ripple equation instead of a torque ripple table so as to reduce the amount of Digital Signal Processor (DSP) memory. The effectiveness of the proposed position servo system is confirmed using numerical and experimental results.
2017 The Institute of Electrical Engineers of Japan