Modeling,Control And Modulation Of The Post-Fault PMSG Wind Power Generation Systems

Wind power has received extensive attention from many researches all over the world and is an important way to solve the energy crisis and environmental pollution due to its clean and renewable characteristics.Direct-drive permanent-magnet synchronous wind power generation systems have a growing share in the wind power generation market due to their low failure rate,high energy density,high efficiency and low maintenance costs.With the increasing installed capacity of wind turbines,the influence of wind power generation systems on the stability of the power grid is increasingly increasing.The reliability and fault-tolerant operation capability of wind power systems have drawn wide attention from scholars all over the world.Many research show that the power switch and its driving circuit in the converter of wind power system are the highest failure rate component,which seriously influence the reliability of grid operation of wind power system.In order to solve the fault of the power switch in the wind power converter,the topology of the three-phase four-switch(TPSS)converter is taken as the fault-tolerant operating topology of the generator-side converter of the permanent magnet synchronous wind power generation system.Mainly from the normal operation of TPSS permanent magnet synchronous wind power generation system modeling and control,modulation and control of three-phase four-switch(TPFS)permanent magnet synchronous wind power generation system after fault are in-depth studied.Aiming at the TPSS permanent magnet synchronous wind power generation system under normal operation,the mathematical model of the permanent magnet synchronous generator(PMSG),the modeling of the system and the parameter design of the controller are deeply analyzed.A simplified modulation algorithm of TPSS converter is introduced.The mathematical model of PMSG driven by TPSS converter is established.The designed controller parameters can provide good static and dynamic performance of the system.Aiming at the TPFS permanent magnet synchronous wind power generation system after fault,this paper focuses on modulation algorithm of the TPFS converter and the neutral point DC bias voltage suppression.First of all,the basic principle of the TPFS converter reveals the root cause of the neutral point voltage fluctuation.Under the condition of TPFS low-speed permanent magnet synchronous generator system,the defects of the second-order low-pass filter in neutral point DC bias voltage suppression is pointed out.The adaptive second-order notch filter can make up for the shortcomings of the low-pass filter.A neutral DC bias voltage suppression strategy using fault phase current compensation based on adaptive second-order notch filter is proposed.Finally,the detailed simulation and experiment verify the correctness and practicability of the research.