Capacity Optimization And Stability Study Of Wind/solar/thermal System With Constant Power Loa

The rapid development of global economy and the dramatic increase of population have led to the increasing shortage of energy and water resources.Therefore,it is important to study renewable energy and change the existing energy structure to alleviate the shortage of energy and water resources.The battery used for smooth scenery output in the process of solar and wind energy utilization will cause pollution to the environment;with the development of concentrated solar power(CSP),it has become possible to replace the battery with a thermal energy storage system,while the waste heat from concentrated solar power generation can be desalinated,so the combination of concentrated solar power generation in traditional wind/solar power generation has received wide attention from scholars in various countries.To solve the problems of how to use thermal energy storage system for smooth scenery output and the high cost of battery to pollute the environment,this paper proposes a wind/solar/ concentrated solar power hydropower co-generation system.In order to maintain the stability of the hydropower co-generation system,the stability problem caused by the power electronic converter in the hydropower cogeneration system should be solved.Based on this,the research content of this paper is as follows.Firstly,this paper proposes a wind/solar/CSP hydropower co-generation system,which replaces the battery with a concentrated solar power generation system with a large-capacity thermal storage tank,avoiding the environmental problems and high costs caused by frequent battery replacement,while using the waste heat from the steam turbine to connect to the low-temperature multi-effect distillation equipment for desalination,improving the utilization rate of thermal energy;the working principles of photovoltaic panels,wind turbines,polythermal power generation,low-temperature multi-effect distillation,and reverse osmosis equipment are explained.The working principles of PV panels,wind turbines,concentrated solar power,low-temperature multi-effect distillation,and reverse osmosis equipment are described,and the mathematical model of the system is established.Then,the capacity optimization was carried out by using multi-objective particle swarm algorithm,and the two objectives of levelized energy cost and design power satisfaction rate of the system were used as the optimization objective function,and the number of PV panels,the number of wind turbines,the area of heat collection field and the capacity of heat storage tank were used as the decision variables,and the optimized levelized energy cost was reduced by 24.4% compared with the wind/solar/battery system when the design power satisfaction rate was the same;in addition,a sensitivity analysis was conducted to optimize the system for different working conditions of PV panels,wind turbines and polythermal power generation.,a sensitivity analysis of the system was also performed to optimize the system for different wind turbines,PV panel prices and different operating conditions of concentrated solar power system.Finally,the impact of a large number of connected power electronic converters on the stability of the hydroelectric co-generation system is analyzed,and the system containing constant power load is modeled,and the storage based virtual impedance power compensation method is introduced based on the model improvement to improve the system stability,and simulated in MATLAB/Simulink platform,and the comparison results show that the method can effectively maintain the stability under the constant power load The comparison results show that the method can effectively maintain the stability under the influence of constant power load.