Study On The Actuator System Of The Speeding High-power DC Brushless Motors

The position servo-control system controls the precise deflexion of the servo-actuator and ensures various dynamic and static performance of the servo-actuator, Such as fast response, high precision, and good stability. The electric servo-actuator which has small volume, high integrated level and digitization has become the tendency of servo-actuator's development. Therefore, it is of great theoretical and engineering importance to study and design DSP-based high performance position servo-control system for brushless DC motor.The paper first briefly introduces the characteristic and principle of the brushless DC motor (BLDCM) used in this servo system. The classical three loop control of position-speed-current is adopts by this position servo-control system by analyzing the system performance requirement and common control strategy of BLDCM. The position loop adopts nonlinear PID to achieve the design requirement of the system.The paper presents a improved PWM modulation by analyzing the traditional PWM modulation and combining with traditional DC motor H-bridge PWM modulation. This modulation method improve the sensitivity, rapidity and stability of the system. This paper presents the artificial experiment waveforms of the position servo system by simulation.The paper analyzes and designs the hardware circuit of the position servo-control system, such as the interface circuit of communication between the position servo controller and the main controller based on 1553B communication protocol bus; the core control circuit based on dual-DSP; the signal treating circuit that translates the level of every feed-back signals; the main circuit and its drive circuit of the three phase inverter based on MOSFET. This paper programs the software of the BLDCM position servo-control system based on TMS320F2812, by optimizing the hardware design of the system.The paper develops a set of independent four path position servo controller for permanent magnetic BLDCM and evaluates the design with experimental study. The rationality and validity of the control strategy employed in the system is verified by the experiment results, the performance of the controller achieves the design requirement, and the system could run steadily.