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Research On DC Microgrid Hybrid Energy Storage Power Balance Control Strategy

Posted on:2021-01-11Degree:MasterType:Thesis
Country:ChinaCandidate:F JiangFull Text:PDF
GTID:2392330602994080Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
With the energy crisis and the pressure caused by environmental damage,the development and utilization of renewable energy has been paid attention to from all walks of life,and the research and application of the microgrid,which is mainly based on renewable energy,has been paid wide attention.Microgrid systems,which are mainly in the form of renewable energy generation systems,energy storage systems and regional power grids consisting of loads,can be connected to large power grids and operated separately in island mode.In this paper,the DC microgrid system consisting of photovoltaic cell power generation system,battery-super capacitor hybrid energy storage system and load composition is aimed at the stable operation of the system,the power distribution control strategy of each component of the battery-super capacitor hybrid energy storage system is studied,and the working state of the system is analyzed,including:The photovoltaic cell power generation system composed of DC microgrid system,and the maximum power tracking control principle of the maximum power of photovoltaics is analyzed by simulating the simulation of the curve of different output characteristics.The working principle of the bidirectional DC/DC converter in the mixed energy storage system is analyzed.The hybrid energy storage elements are connected to the topology of the microgrid system through their respective bidirectional converters,which can realize the complementarity of the energy storage characteristics of the two energy storage elements and extend the service life of the battery.Then,according to the structure of the hybrid energy storage system,the working state of the two energy storage elements is analyzed,according to the energy storage characteristics of the battery and supercapacitor,the difference between the power of the photovoltaic cell and the power of load consumption is regarded as the system fluctuating power,the system fluctuating power is divided into high frequency and low frequency two parts by the low-pass filter method.The battery as the power-based energy storage element mainly suppresses the low-frequency component,and the super-capacitor as the main energy storage component is reduced between the high-frequency components.The control strategy of the energy storage system adopts the double closed-loop fuzzy PI control strategy,and the double closed-loop fuzzy PI control strategy is simulated and verified in MATLAB/simulink,which stabilizes the bus voltage constant,and can realizethe stable and fast charge and discharge control of the energy storage element.According to the relationship between the power of the photovoltaic power generation system and the power consumption of load,and the capacity state of the energy storage element,the working state of the hybrid energy storage system is divided into six modes,and the working state of the energy storage element in each mode is analyzed.The simulation model of photovoltaic cell,hybrid energy storage system and constant power load is built in MATLAB/simulink,and the correctness of power balance control strategy is verified by the simulation of six modes,which can maintain the stability of the bus voltage in all modes.
Keywords/Search Tags:DC microgrid, Photovoltaic power generation, Hybrid energy storage, Power distribution
PDF Full Text Request
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