This article presents a novel electrical/mechanical hybrid 4-redundancy brushless DC torque motor （BLDCM）, which has found applications in direct drive actuators （DDA） of aerial vehicles. This motor is characteristic of electrical/mechanical hybrid 4-redundancy by securing two stators along with two rotors on the same shaft. Each stator contains two sets of windings embed- ded in separated slots. Furthermore, compared to the scheme of two electrical dual-redundancy BLDCMs linked by a mechanical transmission, the proposed motor has lower volume and lighter weight, eliminates the nonlinearity caused by the gap of the me- chanical transmission, moderates the requirement for the torque balance between redundancies and reduces the cogging torque by shifting the magnets. Both magnetic circuit calculation and the finite element analysis （FEA） of the electromagnetic field are conducted to optimize the design process. A prototype motor has been produced and tested. The results indicate that its perform- ances comply with the requirements presented by designers. Moreover, the position frequency response of the prototype in the DDA＇s unloaded situation has also demonstrated the fulfillment of desired dynamic characteristics.
以高性能单片机C8051F005和全桥脉宽调制(PWM,Pulse W idth Modula-tion)驱动电路3955为核心实现了一种结构简单的高性能、多细分、微型化两相混合式步进电动机驱动器.该系统采用正弦波电流细分驱动和双极性、固定关断时间的恒流斩波控制方式,可调的电流衰减模式可以进一步改善步进电动机绕组的电流波形.驱动器最高细分数为256,提供细分选择、正反向控制、半流控制、使能控制,以及过压、欠压、过流、过热等电动机驱动器的保护功能.此外,系统还具有在系统调试和升级能力.从驱动器的总体设计、不同细分下电流参考信号生成和绕组电流控制等方面对该方案进行了详细的论述,实验结果证明该步进电动机高细分驱动器方案结构简单、可靠性高、运行平稳,具有良好的运行矩频特性.
电气双余度是一种常见的无刷直流电动机(Brushless DC motor,BLDCM)的余度形式。极弧系数直接决定着电气双余度BLDCM的电动势(Electromotive force,EMF)的平顶宽度,而EMF波形对电气双余度BLDCM的电磁转矩波动有着直接的影响;并且极弧系数对电气双余度BLDCM的定位转矩也有着显著的影响。本文针对电气双余度BLDCM,研究了极弧系数对其转矩波动的影响。首先分析了由非理想EMF波形引起的电气双余度BLDCM电磁转矩波动;然后,采用电磁场有限元分析,计算和分析了极弧系数对电气双余度BLDCM的EMF波形和定位转矩的影响;进而得到了有助于减小各种转矩波动的极弧系数取值范围。最后通过示例的计算分析给出了电气双余度BLDCM极弧系数选取的参考方法。
