Control Method Research On Grid Connected Photovoltaic Inverter Considering Disturbances

With the development of economy and the progress of society,the demand for electricity is increasing.At present,more photovoltaic micro grids are incorporated into the big power grid,and how to make more efficient use of their power generation is a hot research topic.The energy generated by photovoltaic cells is first boosted by the Boost Circuit,and stabilizes the volatile energy generated by photovoltaic cells.And the top of the Boost circuit is tracking the most powerful points to make sure that the energy generated by the photovoltaic cells owns a high energy-efficient.In the end,the inverter turns direct current into alternating current to the power grid,and the stability of inverter can improve the efficiency of the whole grid system.So the model predictive control for the Boost circuit and the robust control of photovoltaic grid-connected inverter are carried on.The following items are mainly to be done:(1)Set up photovoltaic Boost circuit and the mathematical model of pv inverter.For the mathematical model of the traditional Boost circuit,this paper combines the control mechanism of predictive control to normalize the model.For the mathematical model of inverter,this paper makes a model improvement based on the mixing time delay phenomenon in the real parallel network system,so as to make it more practical.(2)A model predictive control method for Boost circuit is presented.On this basis,the perturbation observer is improved,so that the observer does not have the differential of the output y,so that the observation performance can be achieved better.Meanwhile,the performance index H∞ is set,and the design of the prediction controller based on the improved perturbation observer is proposed,and the composite controller is applied to Boost circuit,so as to better realize the maximum power tracking of pv grid,then the practicability of the improved strategy is simulated.(3)A hybrid time-delay robust control method for photovoltaic grid-connected inverters is presented,by proposing a new lyapunov function,and applying the strange system transformation method,reduces the conservatism of the control system as small as possible,and the improved strategy is simulated and analyzed.