Design And Experimental Research Of Low-voltage PV/Battery DC Microgrid

With the rapid development of China’s economy in recent years,life quality gradually increased,but the environmental problems caused by development also increased significantly.In late December 2016,there were the hazy red alert for 1/3 mainland of China,Beijing,Hebei,Henan,Shandong and other places occurred dense hazy weather.Local governments had to shut down factories and suspend classes for emergency response.Haze not only seriously endanger people’s health,but also more harmed the country’s economic and industrial development.The coal-fired power generation,coal-fired heating and coal-fired production is the main reasons for haze.Solar photovoltaic power generation refers to the use of photovoltaic cells to convert solar radiation energy into electrical energy.It has the advantages of zero emission and no pollution,it can relieve the environmental pollution which is caused by traditional power methods.The combination of photovoltaic cells and energy storage devices can be used as an independent power station to supply electricity to remote areas,which can solve the shortcomings of large input and low utilization rate of the traditional terminal line.At present,the researches for photovoltaic power generation and microgrid of domestic and foreign researchers are mainly focused on the strategy of microgrid upper level control.However,the tracking algorithm for the maximum power point is complicated,it is not suitable for rteal-time control of the microprocessor.And the existing photovoltaic power system structure is mainly connected with the grid or islanding mode,the bus voltage level is high,the number of required accumulator is large,the cost is relatively high,and lack special research on greenhouse microgrid.In this paper,we designed a low voltage PV/Battery DC microgrid system which aimed at the small greenhouse environment with low voltage load.Firstly,,we designed the whole structure of the system and designed the unit structure of each part.Secondly,we designed the system control strategy,including photovoltaic maximum power point tracking algorithm which were suitable for microprocessor fast processing and the control strategy of the energy system,we implemented the intelligent energy exchange among photovoltaic cells,batteries and load.And we built a simulation model in the Matlab/Simulink environment to verify the feasibility of the algorithm.We created a test platform based on TMS320F28335 processor,and designed the hardware electric circuit of signalacquisition,control part,isolation drive and power part.Then we made PCB,and debugged hardware.In the CCS6.1 software development environment,we designed the TMS320F28335 code and verified the feasibility of the design in a laboratory environment.