Feasibility Evaluation And Optimal Control Of Energy Storage Assisted Wind-pv Generation System For Power System Black Start

With the increase of power grid scale,the impact of power outage is more and more serious.As the main measure after the blackout,the fast and efifective black-start scheme can reduce the loss caused by the blackout to the maximum extent.For the areas where the conventional black-start power supply is insufficient,it is an inevitable trend for renewable energy to participate in the black-start by giving full play to the advantages of regional natural resources and selecting the black-start power supply according to local conditions.In areas where wind power and PV power account for a high proportion,the configuration of energy storage constitutes the PV-wind-battery system as black-start power source,which can increase the selection of black-start power source for regional power grid and improve the recovery ability of regional power grid.First of all,this paper studies the participation of PV-wind-battery system in the black-start process.From the perspective of black-start load power demand,this paper analyzes the output power characteristics of PV-wind-battery system from different time scales.It is concluded that when wind power plant and PV power plant participate in the black-start process,there are uncertain feasibility problems.At the same time,it is necessary to study the self start process of PV-wind-battery system.Through the analysis of the black-start load,and through the comparison with the conventional grid load,it is concluded that there are power coordination problems in the process of black-start of PV-wind-battery system,which lays a foundation for the follow-up study.Secondly,the feasibility evaluation method for black-start of PV-wind-battery system is proposed.Considering the characteristics of black-start process,the power prediction method is adopted.The reference value of output power of PV-wind-battery system is obtained by power prediction method to meet the black-start load.The power evaluation method is proposed.The output power of PV-wind-battery system during black-start period is evaluated.Determine the feasibility of black-start of PV-wind-battery system to ensure that during black-start,the PV-wind-battery system can provide sufficient power for auxiliary units of thermal power plant.Then,eombining the requirements of Technical Specifications for Preparation and Implementation of black-start Scheme of Power System(Trial)and Guidelines for Security and Stability of Power System for black-start Transient Process,the research on the self start process of PV-wind-battery system is carried out.Considering the self start process of PV-wind-battery system,the transient model of PV-wind-battery system is built and control strategy of PV-wind-battery system is designed.The self start process and control strategy of PV-wind-battery system are simulated and validated based on PSCAD simulation platform.Finally,based on model predictive control,a coordinated optimization strategy for black-start process is proposed,considering the operation state and characteristics of the PV-wind-battery system,and the operation mode and control mode of the PV-wind-battery system are designed.On this basis,the prediction model and rolling optimization model of the PV-wind-battery system are built by combining the framework of model predictive control.The optimal adjustment of the output power of the PV?wind-battery system is realized,and the black-start simulation of the PV-wind-battery system is carried out based on MATLAB/Simulink.