滤波器在单相PWM整流器中的应用  

Filters Applied in the Single-phase PWM VSR

作　　者：王成智[1] 邹旭东[1] 贾凯[1] 李芬[1] 邹云屏[1] 佘煦[1] 

机构地区：[1]华中科技大学电能与高效重点实验室,武汉430074

出　　处：《高电压技术》2008年第5期942-948,共7页High Voltage Engineering

基　　金：国家自然科学基金项目(50777026);湖北省自然科学基金资助项目(2007ABA051)~~

摘　　要：为消除混叠在PWM单相整流器交流电流反馈信号中的高次谐波分量和直流电压控制外环中的2次谐波分量,在交流电流反馈通道中设置低通滤波器,并使用陷波滤波器衰减直流2次谐波分量;通过在建立电流控制系统模型中发现的内环低通滤波器可有效消除混叠的高次谐波信号的方法保障系统稳定,而对截止频率过高将引起反馈信号相移,改变系统中低频特性,进而影响系统稳定性,则给出了滤波器参数的设定要求;采用直流环节中的陷波滤波器,相比低通滤波器不仅易于在计算精度有限的底层控制芯片中实现,同时更有效消除2次谐波分量,保障系统的高输入功率因数和低谐波分量,同时拥有良好的动态特性。相关仿真分析及搭建4.5kVAPWM整流器样机平台的实验结果验证了以上推论。To eliminate the harmonic components mixed with the useful signal and to depress 2nd harmonic signal in dc voltage, low-pass filter and notch filter are added to the ac-side current feedback link and dc voltage control link in slngle-phase PWM rectifiers respectively. The parameter zone of the low-pass filter is given, and the low-pass filter and notch filter in the de control link is comparatively studied. The notch filter can alleviate the 2nd harmonic signal in the dc voltage signal remarkably, so it depresses the 3nd harmonic component in the ae current reference, and maintains the ac-side input current of the PWM rectifier with less harmonic and higher power factor,moreover, it is easier to be realized in the control chips than the low-pass filter. Due to the fact that the notch filter does not affect other band signals, it will not worsen the dynamic response of the whole system. Finally, the conclusion is verified by simulation results. A 4.5 kVA prototype is constructed, and the related experiment results are testified and analyzed.

关 键 词：PWM整流器 滤波器 系统特性 延时 相位延迟 数字控制系统 

分 类 号：TM461[电气工程—电器]