| At the United Nations General Assembly,China established the goal of "carbon peaking,carbon neutrality".This measure not only provides a green and environmentally friendly way for China’s future energy structure adjustment,but also raises the society’s attention to the micro grid system with clean and sustainable energy as the main body.Vigorously developing the micro grid project is not only conducive to economic development and green transformation,alleviating the power pressure brought by energy shortage,but also provides an effective way for China to carbon neutrality in 2060.However,there are still certain problems in the grid connection process of microgrids at present.The grid connected inverter,which is a key interface of the system,has poor harmonic suppression effect and insufficient dynamic response ability under traditional PID control methods;During the smooth switching process of microgrids,there are problems such as large fluctuations in bus voltage and power oscillation.In order to solve the above problems,this article improves the current control technology of grid connected inverters based on the principles of photovoltaic and wind power generation,combined with the characteristics of energy storage systems,optimizes the smooth switching technology of microgrids,and builds simulation modeling analysis.The main content of this article is:Firstly,a mathematical model based modeling analysis was conducted on the theory of photovoltaic cells,explaining the maximum power tracking technology and three control methods of photovoltaic power generation.The output characteristic curve of photovoltaic cells was obtained through simulation;Secondly,the working principle and control method of wind power generation are systematically studied.The simulation analysis is carried out for the blade tip speed ratio control method.The working characteristics of the energy storage lithium battery in the distributed generation system are modeled and analyzed.According to the above characteristics,the filter resonance analysis and control method analysis are carried out for the grid connected inverter,and the simulation model of the wind/solar storage system is built;Then,in response to the problem of insufficient resonance suppression effect and the need to improve the dynamic response speed of the system in traditional PID current control,this thesis introduces quantum genetic algorithm and adaptively adjusts the rotation angle step size and hybrid collaborative adjustment of quantum mutation probability in traditional PID control.Through Matlab modeling and simulation,it is proven that it can effectively reduce the distortion rate of grid connected current and improve the tracking speed of grid connected current,The results verified the superiority of the improved control method;Finally,an overview of microgrid smooth switching technology is provided.In response to the issues of bus voltage fluctuations and power oscillations,combined with traditional droop control characteristics,voltage amplitude control loops and quantum genetic PID controllers are used to optimize the droop control method.Simulation is conducted in the smooth switching of microgrids to compare and analyze the effectiveness of the optimization.Grid connected inverters are an important component of the wind and solar energy storage microgrid system and a key to the stable operation of the microgrid.This thesis studies the stability and filtering effect of grid connected inverters and proposes an improved control method based on quantum genetic algorithm.This method can adjust parameters in a timely manner,improve the tracking accuracy of grid connected current,effectively suppress harmonic content,and further improve the safety and stability of the microgrid system.In addition,improvements in the control method of smooth switching technology can effectively reduce voltage fluctuations and power oscillations.Through simulation experiments,it has been verified that the operation mode switching of the microgrid system has been effectively optimized,achieving the goal of smooth switching. |
