永磁直流电机电磁设计算例

1、永磁直流电机手工输入 公式计算，不可改.关键判定， 提示说明.数据引用电磁计算程序和算例：序号名称符号或算式单位-一一额定数据1额定功率PnW2额定电压UNV额定转速n nrpm额定电流I NA额定转矩Tn=9.549*PnA1 NN.m起动转矩倍数TstN二主要尺寸及永磁体尺寸选择额定效率n N =Pn/(U n*I n*COS?)*100%计算功率P=(1+2 n /100)/(3 n n/100)*P nW感应电势Ea=(1+(2 n n/100)/3)*U nV极对数p永磁材料类型预计永磁体工作温度tc永磁体剩磁密度Bt20t工作时永磁体剩磁密度Br =(1-(t-20)* a Br/

2、100)*(1-IL/100)*Bt 20t剩磁温度系数a Br%K剩磁温度不可逆损失率IL%永磁体计算矫顽力Hc20KA/M工作时永磁体计算矫顽力Hc=(1-(t-20)* a Br/100)*(1-IL/100)*Hc 20KA/M永磁体相对回复磁导率卩 r=Br/(卩 0*Hc)/1000真空磁导率_7卩 0=4*PI*10工作温度下退磁曲线的拐点bk电枢铁心材料铁芯叠加系数KFe电负荷预估值AA/cm气隙磁密预估值Bs =(0.60-0.85)Br=0.8Brt计算极弧系数a i=0.6-0.75长径比预估值入=0.6-1.5电枢直径41/3Da=(6.1*P*10 / a *A*B

3、s *n* 入)cm电枢直径圆整cm电枢长度La=入 Dacm电枢长度圆整cm极距t =PI*Da/(2p)cm气隙长度cm永磁体结构型式极弧系数a p, a p= a i磁瓦圆心角0 p,0 p= a p*180()永磁体厚度hM永磁体轴向长度Lm, LM=LacmLm, LM=(1.1-1.2)Lacm电枢计算长度Lef ,L ef =La+2 ScmLef 丄 ef =La+A La(h m+ S )cm La=(0.45-0.5)(LM-La)/(h m+S )永磁体内径Dmi=Da+Scm永磁体外径Dmo=Dmi+2hcm电枢圆周速度Va=pi*Da*n n/6000m/s机座材料-

4、机座长度Lj=(2.0-3.0)La,取 Lj=2.8Lamm机座厚度hj=(T* a i* t *Lef*B S/(2*Lj*Bj)cm机座厚度圆整cm计算机座轭磁密Bj, Bi=(1.5-1.8)TT漏磁系数厅,厅=(1.11.3)机座外径Di=Dmo+2hi二电枢冲片及电枢绕组计算绕组型式绕组并联支路对数a, a=p槽数Q槽距t2=pi*Da/Qcm预计满载气隙磁通-4=a * T *Lef*B S*10Wb预计导体总数N=60*a*Ea/(p* / s *nQ每槽导体数Ns=N/Q每槽亓件数u每元件匝数Ws=Ns/(2*u)每元件匝数圆整为Ws实际每槽导体数Ns=2*u*Ws实际导体总

5、数N=Q*Ns换向片数K=u*Q实际电负荷A=N*IM(2*pi*a*Da)支路电流Ia=I N/(2*a)预计电枢电流密度j 2=5-13A/mm2预计导线截面积Acua=la/j 2并绕根数Nt计算导线裸线线径1/2d 0 = (4A Cua/PI)导线裸线线径domm导线绝缘后线径dmm实际导线截面积2ACUa=PI*Nt*d 0 /4mm2实际电枢电流密度j 2=Ia/A CUa实际热负荷 =AJ2槽形选择槽口宽度b02cm槽口高度h021_1cm槽下度半径r22才广；1cm槽上部倒角半径r23Qj,cm槽上部高度cmh2, h2=r23vi槽上部宽度d11cm槽中部高度h22cm槽下

6、部宽度d2cm槽下部倒角圆心距d3L JIcmcm槽咼ht2d2齿宽bt2,近似取平行齿cm槽净面积2 2As=PI*(r22 +r23 )/2+h22(d1+2r22)+r2 3*d3-Ci(PI*r22+2*h22+d1)cm2槽绝缘厚度Cicm槽满率S=Nt*Ns*d2/As%线圆平均半匝长度Lav=La+Ke*Da, Ke=(1.35,p=1)cm电枢绕组电阻2Ra=p *N*Lav/(4*Acua*a )_32Rq0( p a20=0.1785*10 Q .mm/cm)Q_33R5( p a75=0.217*10 Q .mm/cm)Q转子冲片内径D2, D2=(0.15-0.25)D

7、amm转子冲片内径圆整mm电枢轭咼hj2=(Da-2*ht 2-Di 2)/2mm电枢轭有效咼hj21 =hj2 +Di2/8mm四磁路计算气隙系数Ks, Ks =(1.01-1.1)气隙磁通密度4Bs 二*10 /( a * t *Lef)T每对极气隙磁位差4Fs =1.6*K s * S *B s *10A电枢齿磁通密度Bt2=t2*Lef*B s/(b t2*La*Kfe)T电枢齿磁场强度Ht2（ 查磁化曲线图表）A/cm电枢齿磁位差Ft2=2*ht 2*Ht 2A电枢轭磁通密度4Bj2=/ s *10 /(h j2i *La*Kfe)T电枢轭磁场强度Hj2（ 查磁化曲线图表）A/cm电

8、枢轭磁位差Fj2 = Lj2*Hj2A电枢轭部磁路平均计算长度Lj2=PI*(Dj2+hj2)/2pcm定子轭磁通密度4Bj= (T * *10 /(2*hj*Lj)T疋子轭磁场强度Hj1, Hj1（查磁化曲线图表）A/cm定子轭磁位差Fj1=Lj1*Hj1A定子轭部磁路平均计算长度Lj仁 PI*(Dj-hj)/2pcm外磁路总磁位差刀 F=F +Ft2+Fj2+Fj1五负载工作点计算气隙主磁导As 二S/艺F磁导基值-主磁导标么值-外磁路总磁导-直轴电枢去磁磁动势-永磁体负载工作点-实际气隙磁通S六换向计算电刷尺寸，电刷长Lbcm电刷尺寸，电刷宽bbcm电刷尺寸，电刷对数Pb电刷面积Ab=L

9、b*bbcm2每杆电刷数N）电刷电流密度Jb=I n/(N b*Pb*Lb*bb)A/cm2换向器长度Lkcm一对电刷接触压降 U)V换向器直径DK, DK=(0.5-0.9)Dacm换向器圆周速度Vk=PI*DK* n6000m/s换向器片距Tk=PI*D“K换向元件电抗电动势换向亓件交轴电枢反应电动势-换向元件中合成电动势换向区宽度-换向区宽度检杳七最大去磁校核八同工况时的最大瞬时由流突然起动时I max=(UN- Ub)/Ra 20瞬间堵转时I max=(UN- U b)/Ra 75突然停转时I max=(Ea- Ub)/Ra 75突然反转时I max=(UN+Ea-AUb)/Ra 75

10、直轴电枢磁动势-交轴电枢磁动势-换向元件电枢磁动势-电枢总去磁磁动势-电大去磁时永磁体工作点-可逆退磁校核八工作特性电枢绕组铜耗2Pcua = l N *Ra75电刷接触电阻损耗Pb=I N* Ub电枢铁损耗1 322PFe=k*Pi0/50 (f/50)*(mt 2*Bt 22 + mj2*Bj2)k=2-3铁损系数P10/50,查铁损手则W/kgf=p*n n/60Hz电枢齿质量2mt2=7.84*Kfe *La*(PI/4*(Da-(Da-2-32*ht 2) )-Q*As)*10kg电枢轭质量2mj2=7.84*Kfe *La*PI/4*(Da-2*ht2)-Dt22)*10 -3kg

11、电刷对换向器的磨擦损耗PKbm=2* 卩 *Pb*Ab*ps*VkW电刷单位面积压力22Ps=2-6N/cm(或=200-600g/cm )N/cm2电刷摩擦系数n , n =0.2-0.3轴承磨擦和电枢对空气磨擦损耗PBf+PWf 0.04PnW总机械损耗PtW=PKbm+pBf + pWfW总损耗刀 P=Rua+Fb + Pfe +RwW输入功率p仁 rn+EpW效率n =PN/P1*100%电流校核I n=P1/UNA实际感应电动势Ea=Ur U b-I N*Ra75V满载实际转速n=60* a *Ea/p* s *Nrpm起动电流Ist=(U nt U b)/Ra 20A起动电流倍数i

12、st/rn起动转矩Tst=p*N* s *Ist/(2*PI*a)N.m起动转矩倍数Tst/T n算例75.00230.003,900.000.580.1628321224.566.1433988987.79666667178.0865451铁氧体400.3950.37920.20290278.41.0839000431.25664E-060.15DR510-500.97700.303360.70.630.6297709925.2645431225.24OK3.30123.3OK8.2309727520.08瓦片形0.72129.60.853.3钕铁硼3.96铁氧体3.46钕铁硼3.6168铁

13、氧体0.3406451615.47.110.700264589.242.8030303030.2593408110.25OK1.61.2137.6单叠1161.0288715940.0006321674333.968375270.87302341135.4365117135135422 5739645270432 01676.102791110.2970.04142857110.2296704060.23OK0.25漆膜厚度0.01mm0.0415475636.979952136531.1938393半梨形槽0.270.1150.20.10.10.6950.7230.40.4951.1380.

14、2494412910.460187990.02336.6697966110.374148.1351873258.517286540.7860.8OK1.0821.1821.0890.269372444375.48363780.6944412910.7231.25540778665147.940.8354084572162.081012432.9562386871.65978119236415.632708111.5453531001.1373586.31449E-070.000630.60.5310.31811.8238993711.42.53.26.5345127190.6283185310.0006321674.7262722493.8877