The Robust Control Of Two-stage PV Connected In The Micro Grid Based On ? Value

The two-stage photovoltaic grid structure has the advantage of decoupling the input voltage and the input current compared to the single stage photovoltaic grid connected structure.However,the mathematical model of the boost circuit in the two-stage photovoltaic grid structure is an affine nonlinear state space model,which can be transformed into a variable structure linear model.However,it is more demanding for the robustness of the control algorithm,and the shortcomings of the traditional PI control and the linear quadratic optimal control are increasingly exposed.At present,the H_? optimal control theory is a widely used and effective robust control method.When the controller can ensure that the parameters are perturbed within the range of design,the system realizes small range asymptotic stability.In the photovoltaic grid control,the DC voltage between DC/DC and DC/AC is an important indicator of the balance between the PV output and the grid power.The dynamic process of DC capacitor voltage directly reflects the performance of the controller,so the control target of controller in this paper is that considering the two stage inverters model uncertainty and the PV output intermittent in grid connected condition,it is to ensure the dynamic response ability of the DC capacitor voltage and realize PV connected in grid flexibly by m robust control.The DC/AC current inner ring loop is still using the traditional feedforward control.However,during the design of the outer loop controller,the perturbations of the duty ratio and the perturbation of the inner ring parameters are fed into the control structure in the form of multiplicative perturbation.With the capacitance voltage taken as negative feedback,and the output voltage of photovoltaic power generation used as interference,a hybrid sensitivity function is constructed to solve the outer loop controller.Finally,the simulation model is built in MATLAB/Simulink,and the feasibility and effectiveness of the proposed method are verified.