Research On Hybrid Voltage Source Control Strategy Of Direct-Drive Wind Power And Photovoltaic Of New Energy Microgrid

In recent years,environmental degradation and energy supply have attracted extensive attention.Wind power generation and photovoltaic power generation have become important sources of power supply all over the world.In order to solve these problems,many scientific research organizations are committed to the development and utilization of renewable energy such as wind energy and solar energy.High permeability renewable energy power generation system has gradually become the development goal of power system.However,under the high permeability of renewable energy,microgrid is vulnerable to the disturbance of random renewable energy output.Microgrid frequency and voltage will fluctuate,and even lead to the collapse of microgrid system.At present,many wind energy and photovoltaic power sources are connected to the microgrid by the way that the power grid follows the current source.Due to the uncertainty of wind energy size and light intensity,the output of wind turbine and photovoltaic fluctuates,which destroys the reliability of the microgrid system.Therefore,in this paper,the distributed wind energy is connected to the microgrid in the form of voltage source,and the distributed wind energy voltage source control strategy is designed to enable the distributed wind energy to actively participate in the frequency and voltage regulation of the microgrid,so as to ensure the safe and stable operation of high permeability renewable wind energy.This thesis establishes the model of wind solar hybrid voltage source microgrid based on direct-drive permanent magnet synchronous generator and photovoltaic,and formulates the voltage source control strategy of wind power and photovoltaic hybrid microgrid.Through the eigenvalue analysis method,the feasibility of the hybrid voltage source control strategy is verified theoretically.Combined with RT-LAB and dSPACE hardware in the loop experiment,the feasibility of direct-drive wind power and photovoltaic power generation participating in the frequency modulation of microgrid system is proved.The specific work arrangement is as follows:Firstly,this thesis analyzes the composition architecture and maximum power operation characteristics of new energy wind power and photovoltaic hybrid microgrid.The hybrid microgrid is composed of direct-drive permanent magnet synchronous generator system,photovoltaic power generation system and energy storage system.The wind power and photovoltaic power generation system are introduced respectively from the power principle.The operation principle of direct-drive permanent magnet synchronous wind turbine and photovoltaic power generation are described,and the direct-drive permanent magnet synchronous fan model and photovoltaic model are established.In order to make full use of wind energy and solar energy,the operation area of wind turbine and photovoltaic is analyzed.Through the calculation of wind power output curve,the maximum power control strategy of wind energy and photovoltaic in hybrid microgrid is designed.Secondly,the voltage source control strategy of direct-drive wind power system and photovoltaic power generation system in hybrid microgrid is designed.Considering the relationship between the power flow of the back-to-back converter and the intermediate DC voltage in the direct-drive wind power system,the direct-drive wind power DC voltage control strategy is designed in the generator side converter control system,and the direct-drive electromechanical voltage source adaptive droop control strategy is designed in the grid side converter control system.Through the analysis of photovoltaic maximum power curve and intermediate DC voltage,the adaptive droop control strategy of photovoltaic voltage source is designed.Then,in order to theoretically verify the feasibility of wind power hybrid voltage source microgrid control strategy and study the small signal stability of hybrid microgrid,the dynamic modeling of hybrid microgrid system is carried out,and the state space model of the system is derived.The stability of hybrid microgrid system is analyzed by using the basic theory of eigenvalue analysis method.Through the participation factor analysis,sensitivity analysis and dynamic analysis of solar primary energy,the correctness of the designed hybrid voltage source control strategy of direct-drive wind power and photovoltaic is verified.Finally,in the RT-LAB and dSPACE real-time simulation platform,the semiphysical real-time simulation experiment of the designed direct-driven wind power and photovoltaic hybrid voltage source microgrid control strategy is carried out,and the simulation results are analyzed to further verify the effectiveness of the new energy microgrid direct-driven wind power and photovoltaic hybrid voltage source control strategy and the feasibility of voltage source direct-driven wind power and photovoltaic power generation participating in the frequency modulation of microgrid system.