Multi-objective visual design method of control system for synchronous motor drives

Design of current controller for synchronous motor drive system can hardly achieve the desired time- and frequency-domain specifications simultaneously, therefore a multi-objective visual design method is proposed. D-partition technique, which is suitable for nonlinear system, is applied to obtain the controller parameters stable region. In order to improve the stability and dynamic property of synchronous motor drives, frequency-domain specifications such as gain margin and phase margin, time-domain specifications such as overshoot and settling time are considered. Firstly, these specifications are analyzed using three-dimensional (3D) visualization technique. The 3D graphs of gain margin, phase margin, overshoot and settling time changing with controller parameters in the stable region are plotted, respectively. Furthermore, to meet the desired requirements, a multi-objective visual design method is proposed and an optimization region is obtained, which shows the relationship between the desired requirements and the controller parameters. Finally, optimal controller parameters can be derived from the optimization region which meet the requirements of practical engineering. The design process is intuitive and clear, meanwhile time- and frequency-domain specifications can be achieved simultaneously without trial-and-error. Simulation and experimental results verify the proposed method of effective and practical.