两级式单相逆变器输入电流低频纹波分析及抑制

Low Frequency Input Current Ripple Analysis and Reduction in a Single Phase Inverter With Two-stage Structure

50Hz单相逆变器时变特性导致前级直直变换器输入电流中含两倍频100 Hz低频纹波,将有可能诱发变换器之间相互作用问题,如稳定性问题、输入纹波电流限制等。基于反向电流增益Ai(s)(输入电流对输出电流)模型,提出一种新的方法,用于分析直直变换器低频纹波特性。建立不同控制方式下的Ai(s)模型,并通过SABER软件仿真得到验证。指出并验证平均电流控制方式相比电压控制方式及开环控方式,在输入电流低频纹波抑制方面更有效,并基于Ai(s)模型给出相关的设计准则。最终给出不同控制策略下输入电流低频纹波仿真及实验作为验证。

Due to the time-varying characteristic of a single phase DC/AC inverter, its front-end DC/DC converter tends to draw an ac ripple current with double output frequency, which may cause interaction issues such as stability problem and input ripple current limit. A novel method was proposed for the low frequency input current ripple analysis, based on the back current gain Ai（s） （input current to output current） model. Mathematical models with different control schemes were built and verified in SABER environment. It was indicated and proved that the average current mode control strategy is more effective than the voltage mode control and the open loop control method. Design principles were presented based on Ai（S）. Simulation and experimental results with these different control schemes were provided for verification.