中文摘要：

为准确研究无刷直流电机绕组电感和电阻对机械特性的影响，从基本磁链方程的角度人手，建立了无刷直流电机数学模型，分析其运行模式并给出了端电压方程表达式。通过分析其换相过程中相电流的变化情况，将整个换相周期划分为两个阶段，并分别列出换相过程的微分方程，推导了各阶段相电流解析表达式以及平均电磁转矩表达式。最后借助Matlab进行仿真计算，深入研究了电机绕组电感和电阻对机械特性的影响。仿真结果表明：当绕组电感增大一倍时，电机机械特性硬度降低了42％；当绕组电阻增大一倍时，电机机械特性硬度降低了48％。通过建立无刷直流电机模型，为电机机械特性的设计提供了理论依据，并可作为工程实际中电机选型的基本方法。

英文摘要：

To accurately determine the effects of brushless direct current motor（BLDCM） winding re- sistance and inductance on mechanical properties, a mathematical model of BLDCM was established by applying the basic phase flux linkage equations and its fundamental operational patterns were ana- lyzed to derive equivalent terminal voltage. By analyzing the change of the phase currents of commu- tation process, the entire commutation cycle is divided into two stages and each with its own differ- ential equation being listed, and the phase current in different stages of the analytical expression and the average electromagnetic torque expression are deduced. Finally, the influence factors of mechan- ical characteristic of BLDCM were computed by means of Matlab. The simulation results show that motor mechanical properties hardness was reduced by 42% by doubling winding inductance and mo- tor mechanical properties hardness was reduced by 48% by doubling winding resistance respectively.The model of BLDCM for electric motor provides fundamental for the design of the mechanical proper- ties and can be used as the basic method for motor selection in engineering practice.