基于锂电池供电短时大负载下永磁无刷直流电机及驱动设计

摘要

通过分析锂电池输出电压随着能量的输出而下降的规律，根据实际的任务结束后的电压设计电机及驱动电路，通过对其机械特性进行分析可以满足正常情况下的输出要求。当电压低于预期值时，可以对无刷直流电机采用混合驱动的方式提高电机的输出转矩和转速，在混合驱动模式能够实现低电压供电情况下与高电压情况下两两驱动方式相同的输出特性。在电机的设计时，可以适当提高电机的额定电压值，从而减轻电机的体积和重量，更适用于航空航天和户外等对电机体积、重量和短时大负载有特殊要求的场合。仿真和实验表明无刷直流电机的额定电压能够根据锂电池的最低工作电压提高10％以上。%By analyzing the rule that lithium battery output voltage decreases with energy consumption,we design the motor and its drive circuitry with reference to the end voltage of the mission.By analyzing its mechanical characters,we can meet the output requirements under normal conditions.When the voltage lies under its expected value,we can use combination drive to raise the output torque and rotational speed of the brushless DC motor.In the combination drive mode,we can achieve the same output characteristics under the low and high-voltage supply.The motor can be designed with a properly raised rated voltage value so as to reduce the volume and weight of the motor and adapt it to aerospace and other outdoor applications where there are special requirements on the volume, weight and short-term heavy load of the motor.Simulation and experiments show that the rated voltage of the brushless DC motor can be raised by more than 10% against the lowest working voltage of the lithium battery.