Research On Small Disturbance Stability Energy Of DC Microgrid

A large number of interconnected power electronic devices in the DC microgrid exhibit a constant power characteristic,which brings the negative impedance effect to the entire microgrid system,while small disturbance factors such as system parameters,load power fluctuations,and circuit noise are all on the microgrid.The stability of the system has a great impact and has become a major technical problem in the development of DC microgrids.At present,many research work is based on the constant impedance load model and adopts linear control.There are problems such as slow system response and poor output stability.Traditional PID and traditional sliding mode control have shortcomings such as insufficient stability and insufficient precision.Therefore,this paper proposes Lyapunov stability control method.Based on the above main problems,based on Lyapunov stability theory,this paper uses Lyapunov stability.Sexual theory has a wide range of system applicability and does not require the advantage of solving complex differential equations.The DC microgrid model with constant power load is taken as the research object,and the stability control based on Lyapunov function is designed,and the small disturbance factor is fully considered.Firstly,the mathematical model of DC microgrid with constant power load is established.The load side virtual impedance compensation strategy is demonstrated and introduced,and the microgrid model is improved by d-q transformation.Secondly,using MATLAB simulation software,the pre-compensation and post-compensation micro-grid transfer function model is established by frequency domain analysis,and the stability and stability margin of the model before and after compensation are analyzed.Finally,the MATLAB/Simulink simulation model was built,and the traditional PID control,traditional sliding mode control and Lyapunov stability control strategy were applied to the microgrid control,and their control effects were compared.At the same time,the Lyapunov stability control disturbance factor was improved and improved.Robustness.The simulation analysis by MATLAB/Simulink shows that the Lyapunov stability control overcomes the above shortcomings while satisfying the stable control.Under the same conditions,the system control input,bus voltage,constant power load terminal voltage fluctuation is smaller,and In line with the microgrid stability requirements,the simulation results also show that Lyapunov stability control has faster response speed and smaller steady-state error,so the research work in this paper supports Lyapunov stability control to maximize the implementation of constant power.Stability and system robustness of a load DC microgrid.Figure 69 table 5...