阅读说明：本技术 无刷直流电机控制方法、控制装置和电动工具 (Brushless direct current motor control method, control device and electric tool ) 是由 张传兵 朱行 于 2018-05-25 设计创作，主要内容包括：本发明涉及一种无刷直流电机控制方法、控制装置和电动工具,用于控制无位置传感器的具有三相(A、B、C)的无刷直流电机,所述方法包括下列步骤：对所述无刷直流电机的A相依次施加第一时间的第一方向脉冲和第二时间的第二方向脉冲,获取A相施加第一方向脉冲时的母线电流值Ia；对B、C相重复上述操作,获取B相施加第一方向脉冲时的母线电流值Ib和C相施加第一方向脉冲时的母线电流值Ic；比较获取的Ia,Ib,Ic的大小,判断转子的初始位置,根据转子的初始位置发送驱动信号驱动所述无刷直流电机换相。上述无刷直流电机转子位置检测方法、控制装置和电动工具在静止位置采用脉冲法检测到转子的位置,能够根据转子的位置进行换相,提高了换相的准确性,进而提高了启动成功的概率。(The invention relates to a brushless DC motor control method, a control device and an electric tool, which are used for controlling a brushless DC motor with three phases (A, B, C) and without a position sensor, wherein the method comprises the following steps: sequentially applying a first-direction pulse at a first time and a second-direction pulse at a second time to the phase A of the brushless direct current motor to obtain a bus current value Ia when the phase A is applied with the first-direction pulse; repeating the operation on the B, C phase to obtain a bus current value Ib when the first-direction pulse is applied to the B phase and a bus current value Ic when the first-direction pulse is applied to the C phase; and comparing the obtained values of Ia, Ib and Ic, judging the initial position of the rotor, and sending a driving signal to drive the brushless direct current motor to change the phase according to the initial position of the rotor. According to the brushless direct current motor rotor position detection method, the control device and the electric tool, the position of the rotor is detected in the static position by adopting the pulse method, the phase change can be carried out according to the position of the rotor, the phase change accuracy is improved, and the starting success probability is further improved.)