基于自适应ESO观测器的直流电压控制实验分析

Experimental Analysis of DC Voltage Control Based on Adaptive ESO Observer

针对单相并网逆变器的输出存在双频纹波,提出一种LC谐振电路来滤除纹波。现有方法未考虑LC谐振电路与主电容器发生共振导致稳定性下降,设计一种虚拟电阻(VR)的主动阻尼方法来抑制LC谐振峰。系统中非线性和外界扰动引起控制量参数变化给当前设计带来挑战,基于此,提出一种自适应可扩展状态观测器(ESO)控制器,通过ESO来估测总扰动(非线性,负载阶跃变化,外界扰动等),以前馈的方式进行补偿。通过和常规ESO控制器进行性能比较,结果表明所提出的方法不管是稳态下还是负载阶跃响应下的瞬态响应和鲁棒性都优于所比较的方法。

There are two dual-frequency ripples existed in single-phase grid-connected inverters,and an LC resonant circuit is recently proposed to filter the ripples.However,the existing method does not consider the problem of stability degradation due to the resonance of the LC resonant circuit with the main capacitor,and an active damping method based on Virtual Resistor(VR)is designed to suppress the LC resonant peak.In addition,the problem of non-linearity in the system and the change of control parameters due to external disturbances poses a great challenge to the current design.Based on this,an adaptive extended state observer(ESO)-based controller is proposed to estimate the total disturbances(nonlinearities,load step changes,external disturbances,etc.)by ESO and compensate them in a feedforward compensation in a feed-forward manner.A performance comparison with the conventional ESO controller shows that the proposed method outperforms the compared method in terms of transient response and robustness in both steady state and load step response.