Research On Frequency Stability Of Island Microgrid Based On LPPT Droop Control

The island is rich in renewable resources,and an important measure to promote the stable development of the island economy is to establish a stable and reliable island microgrid.With the continuous development of technology,solar-based renewable energy has become a hot electrical research direction worldwide.However,when such intermittent energy sources are the main source of power in the microgrid,their intermittent output can cause fluctuations in the system.With the increase of the installed capacity of renewable energy in the microgrid,the fluctuation caused by it has a greater impact on the microgrid.Therefore,the large-scale application of intermittent energy in the microgrid still needs in-depth research.In order to improve this phenomenon,This paper further explores the ways in which photovoltaics and other energy sources are connected to the grid.The research on the source-load power balance method of the microgrid is carried out to improve the frequency control method of the microgrid power supply,and further improve the frequency modulation capability of the system.This paper systematically explains the definition and structure of microgrid;and expounds the development trend of this field in the world today,and establishes the research significance of microgrid frequency control.The photovoltaic power supply structure and its working principle and mathematical model of the island microgrid are elaborated.The photovoltaic power output characteristic curve is analyzed,and the maximum power tracking control and inverter control are introduced.The microgrid power control technology is described,detailing the droop control.Finally,a variable rate LPPT(limited power point tracking)control algorithm is proposed.LPPT is a control method for extracting the required power value from photovoltaic power sources.In the island microgrid,the photovoltaic power generation system is operated in the LPPT mode,and the balance is balanced.The source-charge power within the microgrid,which in turn stabilizes the power supply frequency.At the same time,considering the characteristics of the island load,a low-frequency load shedding strategy is proposed to fully exert the ability of the load to actively participate in frequency modulation.In this paper,the simulation model of each part of the island microgrid is studied in detail,and the island microgrid model is built based on MATLAB/Simulink platform.The simulation results are used to verify the frequency control method based on LPPT droop control and low frequency subtraction.The rationality and feasibility of the loading strategy.