Research On The Maximum Power Point Tracking Technology And The Design Of Monitoring System For Wind-PV-ES Hybrid Micro-Grid

In recent years,the words about air quality such as "fog","PM2.5","Mask"frequently appear in the public eye,which show that air pollution seriously affects people’s life.Environmental problems are closely related to use of fossil fuels and other non-renewable energy.Solar and wind energy as the new energy of clean and economy have been hitherto unknown attention.With the wind-PV-ES and other distributed power supply access,micro-grid monitoring requirements are getting higher and higher.Under this background,this thesis was written on the basis of the micro-grid system which was developed by Northeastern University and Liaoning Electric Power Company.A monitoring system for wind-PV-ES hybrid micro-grid was designed in this thesis with the help of AT89C51 as control chip.Completed the data acquisition and environmental testing instrument research and development,the results have reached the design requirements.The maximum power point tracking technology in photovoltaic power generation and wind power generation was deeply studied in the end.The main works of the thesis are shown as follow.(1)The basic principles and mathematical models of three kinds of micro-power sources,including photovoltaic power generation system,direct-drive permanent magnet wind power generation system and storage battery energy storage device are researched.The emulation model of three kinds of micro-power supply is built and simulated under MATLAB/Simulink environment.The simulation results show that the output voltage waveform of photovoltaic power generation system and wind power generation system is of good quality,and the storage battery energy storage device can maintain the constant DC voltage.(2)In order to guarantee solar and wind energy convert into electric energy,the development of micro-grid power generation system is an indispensable link.Aiming at solving the problem of low efficiency of photovoltaic conversion,this thesis is also with the help of the maximum power point control algorithm.Firstly,the principle of photovoltaic power generation and wind power generation is analyzed,and research on the current mainstream algorithm of the maximum power point tracking(MPPT)control.In order to obtain the better power output results with dynamic performance and stable performance.The method of photovoltaic and wind power generation maximum power point tracking based on improved variable step-size perturbation and observation method and fan maximum power point tracking based on improved climbing search algorithm are proposed and simulated.(3)The main chip in this paper using AT89C51 microcontroller micro-grid monitoring system for the hardware and software design.The data acquisition circuit includes DC current collecting circuit,DC voltage collecting circuit,AC current collecting circuit and AC voltage collecting circuit.The environmental monitoring information includes wind speed,wind direction,temperature and light intensity.In order to facilitate the implementation of remote monitoring system,software design includes client platform of the system.