基于双调制波的单相三电平并网逆变器及电流优化控制

三电平并网逆变器的调制策略复杂,难以直接用DSP芯片实现。本文提出只需DSP一个事件管理器的双调制波三电平SPWM方法,进而推导了基于该方法的并网逆变器暂态数学模型。以此为基础,针对传统并网电流无差拍控制策略对滤波电感变化敏感的问题,提出基于电流瞬时采样的在线电感辨识方法,对无差拍电流控制策略进行优化,从而有效提高了并网电流控制性能。相应的实验结果证明了所提出方法的正确性和可行性。

Dual-Modulation Waves Based Single-Phase Three-Level Grid-Connected Inverter and Current Improvement Control

The modulation strategy of three-level grid-connected inverter is very complexible,and it is hard to be implemented with DSP.A dual-reference waves based three-level SPWM method suitable for implementation by DSP is proposed,and then the dynamic mathematical model of the grid-connected inverter based on the aforementioned PWM method is derived.On the basis,aiming at the problem that conventional grid-connected deadbeat control is sensitive with the change of filtering inductor,an online inductor identification method adopting instantaneous current samples is proposed.The deadbeat current control is improved with the proposed method,thus the grid-connected current control performance is efficient.Corresponding experimental results verify the accuracy and feasibility of the proposed method.