Research On Improved Droop Control Strategy For Optical Storage DC Microgrid

With the continuous intensification of earth energy shortages and environmental pollution problems,clean distributed power supplies are increasingly concerned about people.To maximize the use of distributed energy power,it is necessary to access it into the microgrid,but the distributed energy power is random,intermittent features,which will affect the stability of the microgrid system operation.The energy storage system is an important part of the microgrid,which is important to suppress power and ensure the quality of the power supply.Therefore,the control method of the energy storage system is deeply studied,which has far-reaching significance for promoting the development of the micro-grid.In this paper,the photovoltaic-mixing energy storage DC microgrid is studied,focusing on the sagging control strategy and the overall coordinated control of the parallel storage system in the microgrid,the specific research content is as follows:First,when the DC microgrid is used in the DC microgrid,the battery energy storage system is used in the traditional SOC droop control method,and the problem in system current is accurately distributed and the problems existing in the busbar voltage stabilization.A adaptive improved salary control strategy is proposed for the distribution error problem caused by line impedance and parameter error.The strategy is calculated by the mathematical estimation method,using the bus voltage and the output current information,and resolves the impact of the impedance factor for current distribution according to the line impedance information,considering the actual use of the actual use,in the parallel single order The influence of the parameter error on the voltage set point of the sag control method,by increasing a current control algorithm,effectively corrects the converter voltage setpoint,further improving the current distribution accuracy,ensuring the equalization of SOC between the battery;After the method,in order to eliminate the voltage deviation from the sagging parameters and the line impedance,the output voltage is used to the rated value by the method of translation compensation.Secondly,a multimode management strategy is proposed for the coordinated control problem of the DC microgrid system to deal with power fluctuations.The strategy is a hybrid energy consisting of super capacitors and battery packs,using a virtual capacitor sagging control,by setting frequency points,realizing the power of the mutant to supercapacitance,a gentle power distribution to the battery pack,effective Increased the service life of the battery;on the basis of voltage hierarchical control,combined with the battery-loaded state of the microgrid system into multiple modalities,and realize reasonable allocation of power in different situations,ensuring the stability of the system.run.Secondly,a multi-modal management strategy is proposed for the coordinated control problem of DC microgrid system when dealing with power fluctuations.This strategy uses a virtual capacitor droop control for the hybrid energy storage composed of super capacitors and battery packs.By setting the frequency points,the sudden power is distributed to the super capacitors and the smooth power is distributed to the battery packs,which is effective Increase the service life of the battery;at the same time,on the basis of the voltage stratification control,combined with the battery state of charge,the microgrid system is divided into multiple modes,which realizes the reasonable distribution of power under different conditions and ensures the stability of the system.Finally,a photovoltaic DC microgrid simulation model was built in Matlab/Simulink for the above two research aspects to verify the distribution accuracy of the improved SOC droop control and the stability of the coordinated operation of the system.On the basis of simulation verification,an experimental platform was built to verify the distribution accuracy of the improved SOC droop control in actual use.Both simulation and experimental results prove the effectiveness of the proposed control strategy.