【目的】传统永磁同步电机驱动受限于电解电容的热衰退特性,寿命存在瓶颈。无电解电容驱动系统通过薄膜电容替换电解电容提升了可靠性,但其引入的大电感易导致网侧产生LC谐振。为此,本文提出一种基于虚拟阻尼功率控制的方法,有效抑制了网侧谐振并提升了系统的功率因数与电能质量。【方法】为探究网侧LC谐振的影响因素,推导了无电解电容驱动系统的特征方程,明确了增加系统阻尼以抑制谐振的必要性。优化传统虚拟阻抗控制方案,基于能量守恒与空间矢量脉宽调制控制周期,建立母线电容功率、网侧电感功率与谐振功率的对应关系。通过精准计算谐振功率并转化为电压矢量进行补偿,实现了对谐振的有效抑制。【结果】试验结果表明,本文所提方法在额定转速和高转速工况下均有效抑制了网侧LC谐振,网侧电流总谐波失真显著降低,系统功率因数最高可达0.99。【结论】本文所提方法为无电解电容驱动系统在低成本、高可靠性领域的工程应用提供了参考。

[Objective] Traditional permanent magnet synchronous motor drives are limited by the thermal degradation characteristics of electrolytic capacitors, resulting in a lifespan bottleneck. Electrolytic capacitor-less drive systems improve reliability by replacing electrolytic capacitors with film capacitors, but the large inductors introduced can easily cause LC resonance on the grid side. To address this, this paper proposes a virtual damping power control method that effectively suppresses grid-side resonance and enhances the system’s power factor and power quality. [Methods] To investigate the influencing factors of grid-side LC resonance, the characteristic equation of the electrolytic capacitor-less drive system was derived, and the necessity of increasing system damping to suppress resonance was clarified. The traditional virtual impedance control scheme was optimized, and the corresponding relationship between bus capacitor power, grid-side inductor power, and resonant power was established based on energy conservation and space vector pulse width modulation control cycles. By accurately calculating the resonant power and converting it into a voltage vector for compensation, effective suppression of resonance was achieved. [Results] The experimental results demonstrated that the proposed method effectively suppressed grid-side LC resonance under both rated and high-speed operating conditions. The total harmonic distortion of the grid-side current was significantly reduced, and the system power factor reached a maximum of 0.99. [Conclusion] The proposed method provides a reference for the engineering application of electrolytic capacitor-less drive systems in low-cost and high-reliability fields.

国家自然科学基金(52077100)