【摘要】 LCL滤波器对开关纹波有更好的抑制效果。但由于是三阶系统,传统的控制方法很难对其产生的谐振峰进行抑制。本文在建立改进型离散状态空间方程和改进型观测器的基础上,利用观测值反馈,通过极点配置实现了整个系统的最佳阻尼,在不增加传感器数量的同时明显改善了系统的动态响应。在理论上分析了闭环极点对状态观测器极点配置的影响、状态观测值反馈的稳定范围以及系统参数变化对稳定性的影响。最后在10kW并网逆变器样机上证实了所提出的方案对系统动态和稳态效果的改善,验证了所提出方案的可行性和可靠性。更多还原

【Abstract】 LCL-filter in grid-connected inverter has a better attenuation on switching ripples. But as a three order system, its resonance is difficult to be suppressed using traditional control strategy. This paper, based on an improved discrete state space model and improved discrete state space observer, proposes a method using optimized pole placement theory to achieve the best damping effect of the whole system, which improves the dynamic response of the system without additional sensors. Furthermore, the influence of closed-loop poles on the placement of observer’s poles, as well as the range within which the observation feedback is stable and the impact of system parameters are discussed. A 10kW grid-connected inverter with LCL-filter prototype is set up to verify the effectiveness and robustness of the proposed control strategy and observer configuration.更多还原