基于谐波观测器的Conergy NPC单相逆变器中点平衡策略

Neural-point Balance Strategy for Conergy NPC Single-phase Inverter Based on Harmonic Observer

提出了一种对周期非正弦信号中各谐波含量实时估计的谐波观测器算法,并将其应用于中点平衡策略。在分析单相全桥Conergy NPC逆变器的开关模型与单相SVPWM调制策略基础上,研究一种基于动态控制参数的中点平衡策略;基于状态观测器原理,设计了滤波电容电压的谐波观测器,实时估计出滤波电容电压中各次谐波分量信息和分量正交信息,利用这些估计信息实现中点平衡策略。仿真和实验都验证了基于谐波观测器的中点电位平衡策略可行性与有效性。

An algorithm of harmonic observer of various harmonic contents is proposed for real-time estimation in cycle nonsinusoidal signal, which be applied to neutral point balance strategy. This paper introduces the neutral-point balance strategy based on dynamic control parameters after analyzing the switch model of single phase full-bridge Conergy NPC and space vector pulse width modulation（SVPWM） modulation methods. A harmonic observer for the capacitance and voltage of filtering, based on state observer theory, is designed in order to get information about harmonic signal and orthogonal signal from sampling signal.Meanwhile, the observed information will also be applied to the neutral point balance strategy. Both simulation experiments and hardware experiments verify the feasibility and validity of this balance strategy based on neutral-point potential in harmonic observer.