Permanent Synchronous Pitch Motor Research For Megawatt Wind Turbine

With the development of wind power technology, wind power is mainly the developmentof the core components and technology become the ineviTab trend of wind powerdevelopment. Permanent magnet synchronous motors,as the wind turbine’s keycomponents,have been paid much more attention. Domestic and overseas research onvariable pitch propeller with permanent magnet synchronous motor mainly transplantpermanent magnet synchronous motor of other equipments to variable pitch system.and thelack of variable propeller system characteristics and the characteristics of the motor runningperformance research.Most researches mainly concentrated on the structure improvement ofpermanent magnet synchronous motor and system optimization design,but the characteristicsof running performance of permanent magnet synchronous motor and the analysis of theoptimization design is not enough.Firstly, introduced rotors’ basic structure of permanent magnet synchronous motor,operational principle and the equivalent magnetic circuit, and analyzed the effect of four kindsof rotor structure on the performance of permanent magnet synchronous motor and whichkind of structure can effectively reduce the volume of motor; The motor running principle,which introduced the working principle of permanent magnet synchronous motor and thearmature reaction of no-load and load; Equivalent magnetic circuit of permanent magnet isincluded by the equivalent magnetic circuit of the permanent magnet motor, paved forcalculation of magnetic energy analysis.Secondly, analyzed the parameters which affect the permanent magnet synchronousmotor and performance calculation. Characteristics of permanent magnet synchronous motorparameters include the calculation parameters and structure parameters, among them, thecalculated parameters including the air gap length and the coefficient of air gap, the magneticflux leakage coefficient and the coefficient of arc, the structure parameters include permanentmagnet size, the armature iron core effective length, the stator slot width and the serialnumber of turns per phase, respectively analyzing affect of the calculation parameters andstructure parameters on the performance of the motor;the performance calculation of thepermanent magnet synchronous motor including the calculation of induced electromotiveforce and permanent magnet flux calculation, pay direct axis inductance calculation andcalculation of the electrical resistance R, and contrapose some of the parameters for thesimulation, presented the parameter value change curves of motor performance impact.Thirdly, analyzed changes of space magnetic induction intensity in magnetic fieldproduced by different shape permanent magnets. Based on biot savart law, use therectangular,cylindrical,tiles permanent magnets are calculated by numerical analysis,and tofacilitate comparative analysis magnetic induction intensity produced by three kinds ofpermanent magnet in the same situation, calculation of three kinds of permanent magnets to choose the same material, size and height, and analysis of permanent magnet magnetic fieldchanges the size of the magnetic induction intensity as well as the trend curve. Wind powerprovides the basis for permanent magnet selection of permanent magnet synchronous motor.Finally, based on wind power unit studying,the characteristic analysis of permanentmagnet synchronous motor in the process of system,and under EasiMotor v2.5environmentto design and simulate analysis for permanent magnet synchronous motor. According to thedesign methods and operating characteristics of permanent magnet synchronous motor, andthe wind turbine units variable pitch,the rated torque of the motor, rated voltage and currentand rotating speed index, through calculation and simulation, to complete the calculation inthe design of permanent magnet synchronous motor, finish motor electromagnetic fieldsimulation cloud image analysis.By comparison, optimization analysis, in order to reduce the permanent magneticmaterial and electrical material, and get the permanent magnet synchronous motor whichsatisfied the requirement of properties of high performance. Calculated based on the analysisof the design of the indicators, developed prototype of permanent magnet synchronousvariable pitch motor, permanent magnet synchronous motor and variable frequency drivesystem alignment, completed the motor design index, and obtained the results which meet thedesign.