分数槽集中绕组双馈感应电机电磁特性分析

Analysis of Electromagnetic Characteristics of Fractional Slot Concentrative Winding Doubly-fed Induction Motor

定转子均采用分数槽集中绕组结构的双馈感应电机极槽数接近,气隙中含有丰富的磁动势谐波,谐波极对数磁场相对于转子高速旋转,会引起电机的转矩脉动。为此,通过磁能和虚位移法求解电磁转矩解析表达式,分析不同次数、不同运动方向的谐波磁场对电磁转矩的影响以及转矩脉动的特点;利用编码器的定位测量功能,提出了一种测量样机转子实时位置的方法,从而量化分析感应电压、电磁转矩等参数。最后利用有限元建立样机二维模型,仿真结果表明:转子转速越快,转子感应电压幅值越小,转矩脉动频率越高,转子转速越慢,转子感应电压幅值越大,转矩脉动频率越低,验证了分数槽集中绕组双馈感应电机电磁耦合理论的正确性。

The double-fed induction motor with fractional slot concentrated winding structure with fixed rotor has similar number of pole slots, and the air gap contains abundant magnetic force harmonics. The harmonic pole log magnetic field rotates at a high speed relative to the rotor, which will cause the torque ripple of the motor. Therefore, the magnetic energy and virtual displacement methods were used to solve the analytical expression of electromagnetic torque, and the influence of harmonic magnetic fields with different times and different motion directions on electromagnetic torque and the characteristics of torque pulsation were analyzed. Based on the positioning and measuring function of encoder, a method of measuring the real-time position of prototype rotor was proposed to quantitatively analyze the induced voltage, electromagnetic torque and other parameters. Finally a prototype finite element two-dimensional model, the simulation results show that the rotor speed faster, rotor induction voltage amplitude is smaller, the higher torque ripple frequency, the rotor speed slower, rotor induction voltage amplitude, the greater the torque ripple frequency is lower, to verified the concentration of fractional slot winding doubly-fed induction motor the correctness of the theory of electromagnetic coupling.