Energy Optimization Management Of Off-grid Wind-solar-storage Complementary Microgrid

Microgrid combines photovoltaic power generation system,wind power generation system,energy storage system and electricity load to form an off-grid wind-solar-storage complementary microgrid system.The impact of limited capacity will cause the system to be unable to operate stably.How to maintain the stable and safe operation of the system and optimize energy management is an urgent problem to be solved in the microgrid.This paper mainly conducts in-depth analysis and discussion on the composition structure,energy management,operation control and other issues of the off-grid microgrid,and provides a model predictive control energy optimization management strategy for the off-grid microgrid.The capacity configuration and load shedding strategy to maintain the DC bus voltage provide theoretical support and simulation verification for the energy management and operation control of the microgrid.This paper deeply analyzes the composition framework and working principle of the off-grid wind-solar-storage complementary system.The models of photovoltaic power generation,wind power generation,energy storage and load are modeled and simulated in Matlab/simulink respectively.Photovoltaic power generation converts low voltage to high voltage through Boost,and maintains the maximum output power through MPPT;wind power generation system converts AC to DC through AC/DC converter,and tracks the wind output power to maximize the value through disturbance observation method;energy storage system The DC microgrid is powered by the charging and discharging of the battery capacity,connected to the microgrid through the DC/DC converter,and the off-grid wind-solar storage complementary DC microgrid system is formed by interconnecting the above equipment.For energy optimization management,a model predictive control strategy is proposed,which optimizes the energy of the microgrid and improves the system operation economy by considering two times scales: day-ahead and intra-day.Since the system energy fluctuates randomly with time,there will be errors in the generated power of the system.Model predictive control is used to predict the generated power,and the intraday optimization is used to make rough adjustments to the system,combined with intraday optimization to make fine adjustments,through rolling optimization and the feedback correction adjusts the power repeatedly,so that the energy optimization results are close to the actual operating conditions,and the operating costs of the system are optimized.The off-grid wind-solar-storage complementary microgrid model is used to simulate and analyze the five operation modes under different load conditions to verify the operation stability of the system.The load strategy is used to make the system maintain stability under different conditions.In order to configure a reasonable capacity and remove the appropriate load,the system operating cost is calculated through the day-ahead optimization model,and the appropriate capacity and load are selected under the condition of ensuring the optimal economy.Comparing the waveforms before and after verifying the DC voltage,the analysis results show the effectiveness of the proposed strategy.