Design And Control Of Multi-three-phase Permanent Magnet Wind Turbine

Compared with the inland wind resources,the total wind resources along the coast are 20%-40% more than that of China outback.At the same time,the wind speed is stable and the power generation is big in the sea.The capacity of the global wind turbine power in the sea is increasing and more than10 MW.But the output voltage of the wind turbine is still 690 V.At this time,the wind turbine usually adopts the parallel mode of multiple converters to face the demand of the wind turbine power(the oparallel converters number is more than 5).As a result,the parallel converter of the wind turbine power becomes very complex,the costs are increased,and the power density of the wind turbine system is reduced.However,the circulating current problem of the converters still exists.A modular multi-three-phase permanent magnet wind turbine is put forward to solve the shortcomings of poor consistency of power devices in the converter of highpower wind turbine(?10MW).The structure,principle,mathematical model,modular split rule of stator unit,power equation,output characteristics,fault-tolerant control is study.It is reflected in the following points:(1)The design method of the modular multi-three-phase PMSM is studied.This paper summarizes the characteristics of several groups of near pole slot matching schemes,compares various winding structure forms.The selection rules of module number,winding form,winding coefficient and pole number combination selection are proposed.The design steps of the modular multi-three-phase PMSM in the form of motor unit is put forward for the first time.Referring to the winding load and air gap magnetic load of PMSM,the relationship between the output power of motor unit of the modular multi-three-phase PMSM motor unit and the computing method of the stator outer diameter is established.And the design of the modular multi-three-phase PMSM is completed on the premise of considering the winding temperature rise.The initial dimensions and operation parameters of dual multi-three-phase PMSM and asymmetric six phase PMSM are obtained.(2)The differences between the new modular motor and the multi-phase motor in pole slot coordination,no-load back electrical potential and so on are compared.The output performance of modular multi-three-phase PMSM in normal operation and modular operation is summarized.The winding reconfiguration control strategy of the motor unit is proposed to solve the winding short circuit fault.And the calculation formula of three-phase current vector is derived on the basis of compensating the loss of fault magnetomotive force.The output performance of the modular multi-threephase PMSM in a failure or normal operation is studied.The large fluctuation of motor torque with or wothout fault-tolerant control of the modular multi-three-phase PMSM is discussed(3)Based on the simulation waveforms of the unit motor inductance of the 22 pole24 slot dual module motor,the variation law of inductance of themulti-three-phase PMSM are summarized,and the reasons for the inconsistency of the mutual inductance of the three-phase windings are analyzed.The simplified model of inductance matrix and the mathematical model is established.In order to slove the shortcomings of high current harmonic content of generator side converter,a current harmonic suppression algorithm based on the new current controller is proposed.(4)A 100 k W six multi-three-phase PMSG is manufactured,and the multi-threephase PMSM platform is built.The no-load and light load output characteristics of the six multi-three-phase PMSG are tested,and the correctness of the design method and current harmonic control strategy of the six multi-three-phase PMSG is partially verified.