永磁电机无电解电容驱动系统网侧电流谐波抑制策略

Suppression Strategy of Grid-side Current Harmonics for Electrolytic Capacitor-less Permanent Magnet Motor Drives

无电解电容驱动方式可以延长永磁电机系统运行寿命、降低系统体积。为了提升无电解电容电机驱动系统网侧电能质量,提出一种阻抗重塑的网侧电流谐波抑制方法。通过对无电解电容驱动系统频域特性建模分析,阐明网侧LC谐振对驱动系统导纳的影响,揭示网侧电流谐波畸变与母线电感电流的内在关系。在此基础上,提出一种驱动系统有源阻尼控制方法,通过提取母线电压谐波特征信号,构建反馈控制回路,重塑驱动系统等效阻抗。研究控制方法的优化实现方式,获取有源阻尼电压信号,从而抑制特定频率网侧电流谐波。在5.5kW无电解电容永磁电机驱动平台上验证了所提出控制方法的有效性。

The electrolytic capacitor-less drive can prolong the drive system lifetime and reduce the system volume.In order to improve the grid-side power quality of the electrolytic capacitor-less drive,an impedance reshaping based grid-side current harmonic suppression method was proposed.The frequency domain model of the electrolytic capacitor-less drive system was established and applied to clarify the relationship between the DC-link current and the total harmonic distortion.On this basis,an active damping control method was proposed,and the characteristic signals of the DC-link voltage harmonics were extracted to construct the feedback control loop,hence the drive system impedance could be reshaped.The proposed control method was optimized to obtain the voltage command signal of the active damping control,then the grid current harmonics with specified frequencies could be suppressed.Experiments were performed on a 5.5 kW electrolytic capacitor-less permanent magnet motor drive platform to verify the effectiveness of the proposed strategy.