Research On Capacity Allocation Of Energy Storage System And Control Strategy Of PV-storage Microgrid Based On Probable Error Model

Under the background of the rapid development of new energy power generation,large-scale injection of distributed energy will pose challenges to grid reliability.The distributed PV-storage microgrid can maintain the stability of energy exchange between the microgrid and the main grid by controlling the operating state of the energy storage system.Aiming at the key technology of energy storage applied in microgrid,this paper mainly studies the capacity configuration of energy storage system and the control strategy in the connected/isolated grid mode.This paper takes into account the probable error model for the first time,which improves the accuracy of capacity allocation.The implementation of the control strategy based on the capacity allocation of the energy storage system can better suppress the power fluctuation of the PV-storage microgrid,smooth the power load curve,and improve the equipment operation efficiency and power supply reliability.In order to realize the continuity and reliability of power supply,the control strategies of microgrid stability controller under various operating conditions are studied.In the grid-connected mode,multi-stage based on SPWM technology.A multi-stage complementary control strategy and a Fourier series expansion were used to establish a mathematical model of a multi-stage complementary charging method.It was verified that multiple H-bridge stages can still maintain the stability of the inverter output state variables and filter out Higher harmonics avoid causing damage to the equipment.In the islanded state,considering that the microgrid system is a low-voltage system,traditional droop control often adjusts active power and reactive power at the expense of voltage and frequency stability.Therefore,the reference impedance is introduced to improve the traditional droop control method.The optimal inner loop feedback control system to eliminate the impact of the reference impedance on the power grid,and combined with MATLAB simulation,it proves that the control effect is good.With the Liaoning Solar Energy’s PV-storage microgrid system as an example,the control strategy of the microgrid system is studied and designed.First,analyze the project’s engineering profile,combine the situation of the primary and secondary systems of themicrogrid.The probable error model is used to accurately allocate the energy storage capacity.Combined with previous research,in the working mode,to implement the control strategy of the energy storage system and the stable controller,to ensure the smooth switching between grid-connected and islanded modes,and scheduling center based on stability controller,to achieve the centralized management and control.Through the implementation of various control strategies during the actual operation of Liaoning Solar Energy’s PV-storage microgrid system,the applicability and effectiveness of the control strategies in various operating modes were verified,It has important engineering application value for the research of energy storage capacity allocation and control strategy of PV-storage microgrid.