| As human beings pay more attention to their living environment,people attach improtance to the development and utilization of renewable energy such as wind energy and solar energy.Among them,offshore wind power has many advantages such as no land occupation,stability and small seasonal deviation.But the expansion of offshore wind farms brings about the threat to the safe and stable operation of power grid.Therefore,it is of great significance to expand the application scale of offshore wind power to carry out research on the access and operation control technology of offshore wind power through engineering practice and simulation.Among the mainstream wind motors,the Direct-drive Permanent Magnet Synchronous Generator(PSMG)has the advantages of high energy conversion efficiency,reliable operation,grid-connection and flexible control mode,and is more suitable for the sea wind power generation system.It is one of the research hotspots of the development of offshore wind power at present.This paper focuses on the accession and operational control technology of PSMG,and mainly does the following work:1、The site selection,design and access technology of offshore wind farm are analyzed based on a practical engineering case.It is a systematic project to connect the wind farm to the power grid.The selection and layout of wind motor and all kinds of electrical equipment must take into account both technical and economic requirements.However,the scheme of power grid connection must be compared and optimized according to the actual power grid situation near the landing point.2、Based on the structure and operation principle of PSMG,the mathematical model and equivalent circuit of wind turbine,synchronous generator and PMW converter are established.The maximum power(MPPT)control,pitch Angle control and Boost-Chopper circuit control are described in this paper.In MATLAB/Simulink,a complete direct-driven PMSG wind farm model was built to integrate into the ideal power grid,and the effectiveness of the model and control strategy was verified by simulation.3、The fault characteristics of voltage dips and voltage swells,DC bus voltage variation rule and energy unloading strategy are studied.By analyzing the electromagnetic transient process of the PSMG in different fault processes,a scheme of dynamic voltage restorer is proposed to offset the distortion of the junction point,so as to deal with the problem of voltage fault through.Simulation experiments were carried out on MATLAB/Simulink platform to verify the effectiveness of the strategy under different fault types. |
