Research On Frequency Control Strategy Of High Photovoltaic Penetration Hybrid Power Generation System

The proportion of photovoltaic power generation has continued to increase in recent years.With the increase in the penetration rate of photovoltaic power generation,the power grid frequency modulation capability continues to decline.In addition,The user’s demand for power quality and power supply reliability has caused the high-permeability hybrid power system to gradually transform from a centralized large-scale power grid to a regional interconnected power system.Therefore,it is very necessary to study the grid frequency regulation strategy and method of multi-regional interconnection and high penetration rate photovoltaic grid connection to improve the speed and stability of grid frequency control.Aiming at the problem that the frequency of multi-area interconnected photovoltaic hybrid power generation system is unstable,and traditional methods such as PID,fuzzy logic,fuzzy PID(FPID)and other traditional methods cannot take into account control speed and stability,this paper proposes a variable universe fuzzy PID(VUFPID)load frequency control based on whale-predation algorithm The strategy can effectively improve the power frequency control effect of the system,with faster control speed and smaller steady-state error.The specific research content is as follows:First,a DC fully coupled four-region interconnected high-permeability photovoltaic hybrid power generation system model was established.This paper summarizes the problems faced by frequency control of multi-area interconnected high-permeability photovoltaic hybrid power generation systems and the current research status of power system frequency control technology,and introduces the technical concept of LFC.The basic composition of the photovoltaic hybrid thermal power generation system is analyzed and linearized,and the Simulink platform is used to build a area interconnected photovoltaic hybrid power generation system model.Based on the state space model of the multi-region interconnected high-permeability photovoltaic hybrid power generation system,a DC fully coupled four-region interconnected high-permeability photovoltaic hybrid power system model was built.Secondly,the frequency control strategy is researched with the DC fully coupled four-zone interconnected high-permeability photovoltaic hybrid power generation system model as the control object.This paper introduces three types of LFC control algorithms,and researches them with PID method,fuzzy logic method and fuzzy PID method as representatives.A four-zone interconnected high-permeability photovoltaic hybrid power generation system model with LFC control modules is built through Simulink,and it is obtained The corresponding output current frequency simulation waveform,and its analysis and evaluation.Finally,based on the analysis of the advantages and disadvantages of the three types of LFC algorithms,especially the disadvantages of the traditional methods of slower control speed and larger overshoot,a VUFPID LFC strategy based on whale-predation algorithm is proposed.In order to verify this strategy,a simulation model was built through Simulink,and compared with PID,fuzzy,and FPID,it was verified that the proposed control strategy has a shorter settling time and smaller steady-state error,and has a certain The superiority and effectiveness of.This article contains 72 pictures and 9 tables,77 references.