并网逆变器闭环控制带宽对死区效应的抑制

阐述了死区效应的产生机理及其在开环控制下对逆变器输出基波电压的影响和死区谐波频谱分布情况。在此基础上,通过闭环传递函数带宽分析,定量地分析了闭环系统对死区效应的抑制作用以及控制带宽大小对抑制死区效应效果的关系。以单电流闭环控制的LCL滤波并网逆变器系统为例,进行闭环控制带宽对死区效应抑制的仿真验证。最后,在一台250kW三相并网逆变器上进行实验验证。仿真和实验结果证明了理论分析的正确性。

Suppression Effect on Dead-Time in Close-Loop Control for Grid-Connected Inverter

The mechanism of dead-time effect is illustrated, as well as its influences on fundamental output voltage and harmonic spectrum distribution. Combining the basic analysis and the bandwidth of the system close loop transfer function, the suppression effect on dead-time and the close relationship between the close-loop bandwidth and the suppression effect are quantitatively analyzed. Taking the single loop controlled LCL inverter as an example, the suppression effect of the close-loop control bandwidth on dead-time is verified by simulation. Finally, experiments are performed on a 250 kW grid-tied inverter to check the suppression effect on dead-time. Simulation and experimental results agree well with the theoretical analysis.