The Present Invention Relates To A Comprehensive Control Strategy Of Voltage And Frequency Modulation Of An Optical Storage Integrated Machine

In recent years,in order to achieve "carbon peak" and "carbon neutral" goals,our country has vigorously developed new energy power generation.However,as the installed capacity of new energy power generation occupies an increasing proportion in the whole power system,its randomness and weak frequency modulation also bring great challenges to the traditional power system.In order to solve this problem,this paper studies the integrated control strategy of the optical storage device participating in the frequency and voltage modulation of the power grid.First of all,this paper describes the basic principle of each component unit of optical storage machine.The maximum power tracking technology is introduced in the control of photovoltaic power generation.According to the principle and technical characteristics of energy storage,energy storage is classified into capacity energy storage and power energy storage.The advantages and disadvantages of different energy storage types are analyzed,and the concept of hybrid energy storage is introduced to highlight the advantages of hybrid energy storage over single energy storage.The working principle and mathematical model of supercapacitor and lithium battery are established respectively,and the bidirectional half-bridge DC-DC converter model is established.Secondly,this paper determines the topological structure of the optical storage unit,and gives the corresponding control methods of different modules,including the control method of photovoltaic cell unit,the control method of hybrid energy storage unit and the control method of grid-connected inverter.A low voltage crossing strategy based on power,voltage and current three-loop control is proposed.This paper presents the working mode selection method of optical storage integrated machine,including working mode classification and selection method based on improved clustering algorithm.This paper presents a strategy and load distribution method for optical storage integrated machine to participate in primary frequency modulation strategy.These control methods are the important guarantee to realize the efficient and stable operation of optical storage system.Finally,the correctness and effectiveness of the designed optical storage integrated machine topology and control strategy are verified by simulation.The output voltage and output power of the optical storage unit under different working conditions are tested,and the effectiveness of the designed control circuit is verified.The simulation results show that the optical storage system has good power quality control ability and can suppress voltage fluctuation and frequency fluctuation of the power system.When three-phase short-circuit occurs in the system,the storage device can realize rapid reactive power support.When the local system is loaded,the optical storage device can quickly sense the power and reasonably distribute the power to different energy storage units with mixed energy storage.