基于软件锁相环的无刷直流电机速度控制器设计

摘要

无刷直流电机系统具有转矩电流比高、转速高、动态性能好、可靠性高和易于控制等优点,在中小功率驱动场合应用广泛;但缺点是转矩脉动大并易造成速度波动,目前普遍采用的速度-电流双闭环PI控制在无刷直流电机用于某些负载变化率大及大惯量的速度控制模式下时,可能因速度不稳带来震动、谐振、噪声等问题,文中给出一种基于DSP的改进型双闭环串级控制法,利用速度环增加软件锁相环的方法,有效改善了传统速度电流PI调节器在无刷直流电机大惯量负载中存在的转速波动问题,在实际应用中具有良好的速度控制精度和稳定性。%BLDC is widely used in middle and small power motor drive system and has many advantages, such as high torque current,well dynamic quality, high reliability, etc. Its disadvantage is to be influenced by its high torque fluctuation easily. At present, when BLDC is in the Speed control modes, such as large load variatim rate and high inertia, the commonly used speed-current dual closed loop PI control would bring many faults, like vibration, noise, resonance because of unstable speed. Based on DSP~ this paper discusses about a modified du- al closed loop control method, that is to use speed loop to boost SPLL control which improves the problem existing in traditional speed-cur- rent PI control method, which would bring out speed fluctuation in BLDC system. This design can provide with speed control accuracy and stability in practical applications.