Research On The Capacity Optimization Of Hybrid Energy In Independent Photovoltaic System

Environmental factors,such as lighting and geographical locations,can significantly affect the efficiency of photovoltaic power generation systems.In addition,the energy storage system with a single power source has limitations and cannot simultaneously meet the requirements of power and energy capacity.This paper has adopted hybrid energy storage in independent photovoltaic system and reasonably optimized the capacity configuration of hybrid energy to solve the above problems on the basis of stable operation of the system.Firstly,the thesis analyzes topological structure of hybrid energy storage system,and the structure of hybrid energy storage system is selected by controlling the power of energy storage devices,so as to determine the structure of hybrid energy storage in independent photovoltaic system.The working principles and characteristics of photovoltaic power generation and hybrid energy storage devices are discussed respectively,and the engineering model and energy storage capacity model of photovoltaic power generation are established.Secondly,a first-order low-pass filtering power allocation strategy based on energy balance is proposed,in which vanadium redox battery bears low-frequency power component and super capacitor bears high-frequency power component.A capacity allocation model is established with the life cycle cost of hybrid energy storage system as the objective function,and its constraint conditions are determined,based on the power demand of hybrid energy storage system.APSO is used to solve the rated power and rated capacity of hybrid energy storage system under the constraint conditions,based on the actual case.the energy storage operation characteristics of different load power systems and the influence of different filter coefficients on their capacity allocation and cost are analyzed.The last moment of SOC of the energy storage device is slightly larger than or equal to the initial moment of SOC;the load power fluctuation can be kept within a certain range to optimize the capacity of the system configuration.The larger the filter time constant is,the smaller the capacity of vanadium redox battery configuration is,and the larger the capacity of super capacitor configuration is,the cost rules to decrease first and then increase.Finally,according to this thesis research results,the hybrid energy storage in independent photovoltaic system capacity configuration software is written by Matlab,which verifies the correctness and effectiveness of the hybrid energy storage system capacity optimization configuration model.