伺服驱动器功率器件开关切换会导致母线电压产生纹波，可能造成永磁同步电机伺服驱动系统性能下降、电磁干扰以及谐波问题。为应对上述问题，针对直流供电伺服驱动系统，分析研究了功率器件开关过程对母线电压纹波的影响。首先根据永磁同步电机（permanent magnet synchronous motor, PMSM）工作原理与空间矢量脉宽调制（space vector pulse width modulation, SVPWM）算法，分析了母线电容的纹波电流；然后根据电荷守恒定律，理论分析了七段式和五段式SVPWM调制方式下母线电容容量与母线电压以及电流幅值之间的关系，给出了其简化表达式。最后，通过仿真试验对理论结果进行了验证。

The switching of power devices in servo drive can lead to bus voltage ripple, which may result in performance degradation, electromagnetic interference, and harmonic issues in permanent magnet synchronous motor AC servo systems. To address these issues, the influence of the switching process of power device on the voltage ripple of bus was analyzed and studied for the DC power supply servo drive system. Firstly, based on the working principle of PMSM (permanent magnet synchronous motor) and SVPWM (space vector pulse width modulation) algorithm, the ripple current of the busbar capacitor was analyzed. Then, according to the law of charge conservation, the relationship between the busbar capacitance, busbar voltage and current amplitude under the seven-stage and five-stage SVPWM modulation was analyzed theoretically, and its simplified expression was given. Finally, the theoretical results were verified by simulation experiments.