并网逆变器的无死区效应单周控制策略

Non-Dead-Time Effect One Cycle Control Strategy for Grid-Connected Inverter

提出一种新型的死区设置方案。通过检测电流的极性,在该极性电流下的续流二极管所对应开关管的驱动信号的上升沿和下降沿分别设置死区时间,消除了死区效应对输出电能质量的影响,无需进行死区补偿,降低了控制电路的复杂度。结合单周控制思想,提出了三相并网逆变器的无死区效应单周控制策略。仿真结果表明,无死区效应单周控制策略的并网电流的谐波畸变率明显减小,输出电能质量显著提高,具有普通单周控制策略动态响应快、鲁棒性好等优点。

This paper proposed a novel dead-time setting method. By detecting the polarity of the grid current, the dead time is set in the both rising and falling edges of the drive signal of the switch corresponding to the freewheeling diode of this polarity. The dead time effect on the output power quality was eliminated, and there was no need for dead time compensation, thus the complexity of the control circuit was reduced. Based on the thought of one cycle control, the non-dead-time effect one cycle control strategy of three-phase grid-connected inverter was proposed. The simulation results show that the total harmonic distortion of the grid current with the proposed non-dead-time effect one cycle control strategy is reduced, so the output power quality is improved significantly. The proposed control strategy also has the advantages of fast response and good robustness as traditional one cycle control strategy.