Research On Emergency Control Strategy For Participation Of Wind Photovoltaic And Storage In Power Grid In New Energy High Penetration Areas

With the proposal of the 2020 "dual carbon" goal,China’s energy system is gradually transitioning from traditional thermal power generation to new energy generation.Wind turbines and photovoltaic units are gradually replacing traditional thermal power units as the main energy sources on the power generation side of the power system.However,the integration of a large number of new energy inverters,converters,and other power electronic devices into the power grid has brought new challenges to power system planning and scheduling.Power electronic devices have changed the traditional power flow distribution in the power grid,reduced the active reserve capacity in the power grid,and reduced the active support capacity of the power grid in case of emergency faults.Therefore,it is urgent to develop emergency control strategies suitable for the integration of wind photovoltaic and energy storage(WPES)in high penetration areas of new energy.This article first models wind power generation systems,photovoltaic power generation systems,and energy storage systems,analyzes the different power output characteristics of wind,photovoltaic,and storage,and studies the power control technology of wind,light,and storage grid connected systems in emergency situations of the power grid.The principle of WPES participating in emergency control of power grid safety is derived.Then,taking into account the power regulation characteristics of WPES as well as the technical characteristics of grid prevention and emergency control,a strategy for WPES participate in grid prevention and emergency control is proposed.In the prevention control stage,by reducing the wind and photovoltaic output to reserve active backup capacity,adjusting the backup capacity in the generator output scheduling system,and adjusting the energy storage charging and discharging status to suppress system power fluctuations,the above three measures are taken to ensure that there is sufficient backup capacity in the system to cope with the problem of insufficient system power after the fault occurs.After a fault occurs,priority should be given to filling the system power imbalance with the reserved active reserve amount of wind and photovoltaic power during the prevention control stage.If the backup active power of wind and photovoltaic power during the prevention control stage is insufficient,emergency control should be carried out through joint load shedding optimization.Subsequently,based on the control strategy proposed in this article,with the goal of minimizing the cost of preventive control measures,a preventive control model for WPES participating in the power grid is constructed with constraints on wind,photovoltaic,storage output,and safe operation of the power grid.Based on PSASP software to simulate specific faults that occur in the system,calculate the system power imbalance after a certain fault occurs based on simulation data.Then,with the goal of minimizing the cost of emergency control measures and the constraints of power grid operation safety and system load shedding,an emergency control model for WPES participating in the power grid is constructed.Solve the prevention and emergency control models based on CPLEX software.Finally,the strategy proposed in this paper was simulated and validated in an improved IEEE39 node system.Through simulation experiments,the reserved active power backup for wind and photovoltaic power,generator output adjustment,energy storage charging/discharging amount during the prevention control stage,system power imbalance after a certain fault,and optimal load shedding for each load node were obtained.At the same time,the economic efficiency of the proposed strategy was analyzed,The effectiveness and economy of the control strategy proposed in this article have been verified.