中文摘要：

在无刷直流电机的各种无位置传感器控制方法中,反电势法凭借其简单、实用等优点得到了广泛应用,但当电机静止或转速很低时,反电势过零点不易检测,无法实现电机自起动,因此需要一种控制策略实现电机的可靠起动。提出一种基于模糊规则的无刷直流电机起动策略：以一定频率导通绕组换相,并检测换相时绕组电流;根据电流响应和换相时刻的关系,通过模糊规则判定相对于当前换相指令的电机转子位置;最后对换相指令进行在线调整,避免电机起动过程中失步现象的发生。

英文摘要：

In various sensorless control approach for brushless DC motor （BLDCM）, zero crossing point of back-electromotive force （EMF） method has been widely used due to its simplicity and ease of implementation. However when the motor is at standstill or very low speed, the back-EMF induced in the coil is difficult to detect and the motor can＇t realize self-starting. A startup algorithm is required to start the motor reliably from standstill up to a certain speed where the sensorless control methods based on EMF could take over. A startup strategy was proposed based on fuzzy rules for BLDCM without position sensor. In this method, the motor winding was imposed on a certain frequency voltage for commutation, and the current in the coil was detected. According to the relationship between the characteristic of current response and commutation instant, the rotor relative position was judged by fuzzy rules. At last, commutation command was adjusted on-line to avoid out of step in startup process.