Research On Power Grid Simulator Control Based On Finite Set Model Prediction

Before the distributed generation system is connected to the grid,the gridconnected performance of the distributed generation system must be tested when the grid is normal and abnormal.Because of the randomness and uncontrollability of all kinds of abnormal working conditions in the actual power grid,it is necessary to study the power grid simulator to simulate the normal and abnormal working conditions of the power grid.The existing inverter link of power grid simulator mainly adopts linear control strategy,which has some defects such as complex parameter design and long dynamic response time,so this paper mainly studies the control strategy of inverter link of power grid simulator.The specific work is as follows:1)Firstly,the principle and function of power grid simulator are introduced,and the characteristics of all kinds of power grid simulator structures are compared.The combined structure of front-stage three-phase rectifier and rear-stage three-phase fourleg inverter is selected as the main circuit topology of power grid simulator,and the relevant hardware parameters are designed.2)Aiming at the inverter link of the power grid simulator,firstly,the mathematical model of the three-phase four-leg inverter is constructed in the coordinate system.on this basis,the finite set model predictive control algorithm is used to control the threephase load voltage of the power grid simulator.compared with the traditional linear control strategy,this algorithm does not need to design linear controller and modulation link,which not only simplifies the design process of control parameters.It also improves the dynamic response speed of the system.3)In view of the shortcomings of the conventional finite set model predictive control algorithm,such as unfixed switching frequency and poor voltage waveform quality,the original algorithm is improved in this paper.the improved algorithm retains the superior dynamic response performance of the conventional finite set model predictive control algorithm,and realizes the fixed switching frequency control,which improves the waveform quality of the load voltage of the power grid simulator.The effectiveness of the improved control strategy is verified by simulation.4)Finally,the experimental platform of the inverter link of the power grid simulator based on TMS320F28335 is built,the design principles of the system hardware and software are introduced in detail,and the related experiments of the power grid simulator are completed.The experimental results further verify the effectiveness of the control strategy proposed in this paper.