无位置传感器永磁无刷直流电机的起动控制研究

针对无位置传感器无刷直流电机存在的起动问题，根据无刷直流电机的起动换相时刻与直流母线电压直接相关的特点，提出一种插值起动方法。该方法首先通过改变母线电压值，采集相应的起动换相时刻数据样本。在离线情况下，以母线电压为输入，换相时刻作为输出，拟合出两者之间的3次样条插值函数。开环起动时，该方法能够准确计算出任意母线电压下电机的起动换相时刻；闭环起动时，随着PI调节器控制的母线电压有效值的变化，系统通过插值函数在线修正换相时刻，从而保证电机准确换相。起动完毕后，由软件将系统切换到反电势运行状态。仿真和实验表明，提出的插值起动方法，广泛适用于无位置传感器无刷直流电机的开环、闭环以及相应情况下的带负载起动。

Reasearch on Sensorless PM Brushless DC Motor Starting Control

Aiming at the starting problem of sensorless permanent magnet brushless DC motor (BLDCM), an interpolation start-up strategy is proposed according to the direct relation between the source voltage and the commutating instant. In this strategy, different start-up commutating instant under different source voltages are collected first. Then, cubic spline interpolation functions are fitted off line using source voltages as the inputs and commutating instant as the outputs. During open loop starting, these functions can provide accurate start-up commutating instant under any given source voltage; During closed-loop starting, with the variation of the effective value of the source voltage controlled by PI regulator, interpolation functions can adjust the commutating instant on line to make sure they are accurate. When start-up procedure is over, the system is switched to back EMF running by software. Simulation and experiment results show that the interpolation start-up strategy proposed in this paper is widely applicable for sensorless BLDCM in open loop starting, closed-loop starting and the corresponding starting in loading.