【摘要】 针对无刷直流电机无位置传感器换相存在换相误差的问题,提出一种基于虚拟中性点的无刷直流电机无位置换相误差闭环校正方法。将虚拟中性点与电机驱动电压中性点之间的电压差引出,并对该电压差信号与换相误差之间的关系进行了分析。基于此分析,在换相点前后对该电压差信号采样,两次采样结果求差后得到换相误差控制的反馈量,以该反馈量趋近于零目标建立基于PI的闭环校正回路。实验表明,该方法对换相误差具有很强的鲁棒性,可快速补偿外界因素对换相时间的影响,对于15°滞后角,在1 500 r/min转速下仅需70步,在3 000 r/min转速下仅需40步就能使换相点收敛至准确位置。实验结果验证了该方法的有效性。更多还原

【Abstract】 To reduce the commutation error of Brushless DC motors position sensorless,this paper presents a novel Non position commutation error corrected method achieved by a close loop,and which is based on virtual neutral point of the brushless DC motor. voltage difference between the virtual neutral point and middle point of driving voltage are identified. The relationship between the voltage difference and Commutation error are also analysed in this paper. After that, the voltage difference was sampled before and after the commutation points. These two results are subtracted as feedback quantity in commutation error controller. Then a control loop is established to reduce the commutation error which aim is the voltage difference approaching zero. The control part is a PI controller. In the Experiment,15° commutation error is given to verify the method,The result proves that this method is stable and reliable,and it can component the commutation time quickly when it is influenced by external factors. It only took about 70 steps to convergence to the steady state at 1 500 r / min and 40 steps at3 000 r / min for the 15°.更多还原