摘要：变频器供电条件下，同步电动机的定子绕组电压可以方便地进行调节，电机的电压、电流、功率因数及功率角之间存在内在联系。论文首先在恒定负载和恒定励磁电流情况下，对调压的同步电动机通过相量图进行稳态分析，建立功率角、定子电流及功率因数的计算模型，揭示了电压调节时它们之间的相互关系及其变化规律。最后通过实验验证模型的正确性，指出通过调节同步电动机的定子电压，可对功率因数及功率角之间进行调节，对同步电动机功率因数的调节有一定的指导意义。

关键词：同步电动机；功率因数调节；调压运行；稳态分析
Abstract: The stator winding voltage of synchronous motor supplied by inverter can be easily adjustable. The inherent relations exist between the voltage, current, power factor, and power angle of the motor. The paper firstly analyzed synchronous motor using phase graph at adjustable voltage, invariable load and invariable exciting current. Then, it established the calculating model of power angle power factor, stator current, and power factor. And their inter-relationship and variation orderliness were revealed. Finally, the validity of the model was verified by a case in experiment. The research concludes that the power factor and power angle can be regulating by adjusting stator winding voltage, which can be applied in power factor regulation.

Key words: synchronous motor; power factor regulation; adjustable voltage running; steady-state analysis