| In recent years,in order to solve the problem of energy crisis and environmental pollution,the optical storage micro grid developed on the basis of new energy generation technology and energy storage technology has been widely used.In the optical storage micro grid system,the two-way converter is a bridge connecting photovoltaic panels,energy storage cells and AC power grid,which realizes the two-way exchange of AC and DC side energy,so the two-way exchange of optical storage micro grid is realized The research of converter is of great significance.In this paper,the mathematical model of three-phase voltage type optical storage micro grid bi-directional converter is established firstly,and the control principle and the establishment process of the mathematical model in different coordinate systems are described in detail.The traditional PI feedforward decoupling control strategy is studied,and the control parameters of current inner loop and voltage outer loop are calculated and selected.The control parameters are given by calculation,and the double closed loop control algorithm is realized.In order to optimize the voltage control performance,the voltage loop adopts the sliding mode variable structure control with strong robustness.The sliding mode variable structure controller is researched and designed,the expression of sliding mode is deduced in detail,and the mechanism of sliding mode variable structure is analyzed in detail.Secondly,aiming at the shortcomings of traditional PI feedforward decoupling control in current inner loop,such as complex control structure,multiple coordinate transformation times,no tracking of AC signal without static difference,the current inner loop is improved by adopting quasi proportional resonance control algorithm based on internal model principle,which has the advantages of tracking AC sinusoidal signal without static difference,can reduce the current harmonic content and improve the current quality at the network side.The current inner loop control of the system is based on the two-phase static coordinate system,so it does not need to be converted to the two-phase rotating coordinate system,which reduces the calculation of the system and improves the response speed of the system.In this paper,the mechanism of quasi proportional resonance control is analyzed and studied.A quasi proportional resonance controller in the inner loop of bidirectional converter is designed based on the control principle.The design process is analyzed in detail and the formula is deduced.Then the main parameters of the controller are analyzed and designed.Then two simulation models of traditional PI control and improved composite control are built in Matlab/Simulink.The simulation results under the two control strategies are compared and analyzed to verify the correctness of the proposed control strategy.Finally,according to the requirements of practical use,the experimental prototype is designed,the main circuit components of the prototype are selected,the designed hardware circuit is introduced,and the hardware design and software design of the control circuit are completed.Hardware design mainly includes DSP minimum system design,AC and DC detection circuit and corresponding signal conditioning circuit design,IGBT Driver Circuit Design and auxiliary power module design;software design mainly includes main program design,interrupt service program design and each subprogram design.Finally,the overall program framework and important modules are introduced on tsm320f28335 chip and draw the program flow chart.Figure[66]Table[0]Reference[63]... |
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