基于换相分析的无刷直流电动机机械特性研究及优化

Research and Optimization on the Mechanical Characteristics of Brushless DC Motor Based on the Analysis of Phase Commutation

通过分析无刷直流电动机两两导通换相过程,得出相电流在换相和导通期间的变化规律,并由相电流计算电机的平均电磁转矩,推导出电机的机械特性为非线性关系。在换相期间采用重叠换相技术后能够保持电磁转矩恒定,消除换相转矩脉动,并实现电机机械特性为一直线。在额定电磁转矩下能提高输出转速,更加充分利用电机,优化机械特性。

By analyzing the commutation in the brushless direct current motor,phase current waveforms were gotten in commutation and conduct period.The average torque and mechanical characteristic were deduced from the phase current.And the mechanical characteristic of speed to torque was nonlinear.Overlap commutation technique was used to eliminate the torque ripple and optimize the mechanical characteristic to a line in theory.It increased the output speed at the rate torque by contrast to normal commutation method.The BLDCM was made the best use of capacity,and the mechanical characteristic was optimized at the same time.