分数槽集中绕组(FSCW)结构感应电机气隙中含有丰富的磁动势谐波,电机直接启动会带来巨大的冲击电流和较大的转矩脉动,选择合适的电机启动方法在确保提供电机启动所需的能量,同时最大程度地降低其成本、提高效率。本文将基于FSCW结构的感应电机研究硬启动和软启动这两种不同的启动方式。全电压法(硬启动)是最简单的方法,但其可能会对电机寿命产生影响;降压降频启动(软启动)则是另一个方法,可以减少启动所需的能量消耗。首先,根据绕组理论建立感应电机的数学模型;通过电磁耦合理论的电磁转矩理论,分析了硬启动和软启动两种工况下的启动转矩、非主导极对数谐波磁场对转矩脉动的影响;然后,基于虚位移法推导出电磁转矩表达式;最后,基于电磁转矩理论讨论了两种启动方式下的电磁转矩和转矩脉动。此外,还通过理论计算、有限元仿真和试验验证了软启动的可行性和稳定性。

Fractional slot concentrated winding (FSCW) structure of induction motors contains abundant magnetomotive force harmonics in the air gap. Direct starting of the motor will result in huge inrush current and high torque ripple. Selecting an appropriate motor starting method ensures the necessary energy for starting the motor while minimizing costs and improving efficiency. This paper investigated two different starting methods for induction motors based on the FSCW structure: hard start and soft start. The full voltage method (hard start) was the simplest method but it might adversely affect motor lifespan. Alternatively, reduced voltage and frequency start (soft start) could reduce energy consumption during starting. First, the mathematical model of the induction motor was established based on winding theory. The starting torque and the impact of non-dominant pole-pair harmonic magnetic fields on torque ripple were analyzed under both hard and soft start conditions using electromagnetic torque theory. Then, the expression of the electromagnetic torque was derived using the virtual displacement method. Finally, the electromagnetic torque and torque ripple under the two starting methods were discussed based on the electromagnetic torque theory. In addition, the feasibility and stability of soft start were verified through theoretical calculation, finite element simulation and experimental validation.

江苏省配电网智能技术与装配协同创新中心开放基金项目资助(XTCX202405);江苏省“六大人才高峰”高层次人才选拔培养资助项目(XNY-021);江苏省自然科学基金面上项目(BK20141095)