| Recently,under the pressure of energy demand and environmental protection,distributed power generation related technologies have attracted wide attention due to their advantages in improving energy efficiency and making full use of renewable energy.Due to the inherent shortcomings such as randomness and volatility of distributed power sources such as photovoltaic power generation and wind power generation,energy storage systems are of great significance for the stable operation of microgrid systems.At present,energy storage methods with multiple energy sources have been extensively studied,and the electro-hydrogen multi-energy complementary microgrid has gradually entered the field of scholars.Based on the actual meteorological conditions and load demand,this paper studies the capacity allocation optimization of the electro-hydrogen multi-energy complementary microgrid,the grid-connected current control of the virtual synchronous generator and the off-grid quadratic frequency modulation control.The main contents and work of this paper are as follows:(1)Through the analysis of the working principle of photovoltaic array,electric energy storage system,hydrogen storage system and fuel cell,the electric energy system model including photovoltaic power generation system and energy storage system and hydrogen system model containing fuel cell-electrolyzer-hydrogen storage system are respectively established.The electric-hydrogen multi-energy complementary model is established by the operating mechanism and complementary characteristics of the electric energy system and the hydrogen energy system,which lays a theoretical foundation for the optimal configuration,operation control and energy management strategy of the electro-hydrogen multi-energy complementary microgrid.(2)By studying the operation characteristics of the electro-hydrogen multi-energy complementary microgrid,an optimization configuration method aiming at economy and power supply independence is proposed.By comparing the backtracking search algorithm with the particle swarm optimization algorithm,the effectiveness of the backtracking search algorithm is verified.Sexuality enhances multi-energy complementary energy efficiency and increases system reliability.Through the actual examples,the optimization configuration model and configuration process are verified by simulation,and the configuration scheme under the optimal target is given.(3)Aiming at the problems of current imbalance and large inrush current of distributed power inverter caused by grid voltage imbalance in electro-hydrogen multi-energy complementary microgrid,an improved virtual is proposed by the mechanism of negative sequence component suppression.The synchronous generator control method enables the microgrid to operate stably and independently under the condition of voltage imbalance,and maintains the three-phase balance of the grid-connected current.In addition,for the traditional virtual synchronous generator control,the problem that there is only once frequency modulation,which can not realize the no-error frequency adjustment,a secondary frequency modulation control method based on virtual synchronous generator is proposed to maintain the stability of the system frequency under island operation.The realization of no-error frequency adjustment improves the power quality of the electro-hydrogen multi-complementary microgrid.Finally,the effectiveness of the virtual synchronous generator control grid-connected three-phase current balance control and off-grid quadratic frequency modulation control is verified by Matlab/Simulink software platform.(4)The distributed power supply,energy storage system and corresponding DC/DC converters of the electro-hydrogen multi-energy complementary microgrid are controlled separately.The electro-hydrogen multi-energy complementary microgrid has many distributed power sources and complicated working conditions,which the energy management strategy are designed for.In addition,the control method and energy management strategy are verified by Matlab/Simulink simulation. |
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