Research On Dynamic Dispatch And Control Strategy For A Fully Renewable Integrated Energy System

Nowadays,with the increasingly prominent problems of ecological environment and energy in the world,vigorously developing renewable energy sources(RES)has become an important choice to achieve sustainable development.Compared with the traditional energy system,a fully renewable integrated energy system(FRIES)has the advantages of complete consumption of renewable energy,high energy efficiency,meeting a variety of energy needs,and being close to the user,which is an important way to achieve the goal of "carbon peak" and "carbon neutralization" in the future.However,FRIES has the characteristics of various equipment types,large differences in dynamic characteristics of various types of energy networks,and strong randomness and uncertainty of RES and energy demand,which brings great challenges to the smooth operation of the energy system.Based on the above background,according to the object characteristics and operation characteristics of the energy system,this paper studies a stable,economic,and efficient operation strategy of the FRIES from two aspects: the dynamic dispatch method and the multivariable predictive control method.The main research contents include:(1)To obtain the object model required for subsequent dynamic dispatch and multivariable predictive control,the dynamic mathematical model of the main equipment of the FRIES is studied by using the modular modeling idea and aiming at reflecting the dynamic operating characteristics of key variables of each equipment,and its establishment and simulation are realized based on the MATLAB/Simulink software.(2)A dynamic dispatch method based on a single-layer variable step is proposed.On the one hand,considering the slow dynamic response of the heating links of the gas internal combustion engine and the heat pump,dynamic characteristic models are established to describe them.An objective function considering the dynamic supply-demand deviation index is set,and a dynamic dispatch model is established based on the rolling optimization framework of model predictive control(MPC);On the other hand,a single-layer dispatch step strategy considering the variation characteristics of net electric load is studied and applied to the prediction time domain of each rolling optimization.The simulation results fully verify the effectiveness of the dispatch method proposed in this paper in meeting the heating demand and improving the computational efficiency.(3)A multivariable predictive control method is used to modify dispatch plans,and a two-layer operation strategy of the integrated energy system is proposed.Taking the thermoelectric coupling link between the gas internal combustion engine with waste heat recovery and the heat pump as the control object,a multivariable predictive control method based on the expanded state-space model is established.The dispatch plan is modified by coordinating the power command adjustment of the gas internal combustion engine and the heat pump to meet the tracking of the controlled variables to the set value.The two-layer operation strategy is obtained by combining the dispatch layer and the control layer,and a comparison simulation with the single-layer operation strategy is set.The simulation results show that the two-layer operation strategy can effectively reduce the impact of the prediction deviation of RES and electric load and the model deviation of the dispatch model on the system operation.