Design of High-Bandwidth Motor System Considering Electrical and Mechanical Time Constants

This article proposes a design method for a high-speed response motor system consisting of a motor and load. Various methods have been studied to improve the speed response of the motor system, but the main focus was previously advanced control techniques. However, the dynamic response of the controller can be further improved with the high-speed response motor system. The proposed method improves the speed response by increasing the bandwidth of the motor system, which is the plant of the servo system. Thus, the relationship between the bandwidth, which is an indicator of speed response and the motor system, is investigated. The motor system consists of the electrical and mechanical parameters. As both electrical and mechanical parameters affect the speed response and bandwidth of the motor system, the correlation of the time constants and bandwidth is analyzed. Based on the analyzed results, the process of designing a motor system with maximized bandwidth is introduced. An experimental based friction model is proposed to estimate the accurate speed responses and required torque of the motor system. Therefore, a motor system with maximized bandwidth is designed using the proposed design process and friction model. Finally, the rated power and speed response of the motor system are verified through simulations and experiments.