发布时间 : 星期四 文章三相感应电机设计_题目+实例更新完毕开始阅读fd503d9758f5f61fb636660e
JB?I2258.96??2.685Amm2 AB96.45端环电密
JR?IR659.4??2.64Amm2 AR25087. 定子电气损耗
**2*0.0207=0.0347 Pcu1?I1R1=1.2942×
7.5×103=260.25W Pcu1?Pcu1PN?0.0347×
*88. 转子电气损耗
**2*0.02655=0.0344 PAl2?I2R2=1.1392×
PAl2 = PAl2* PN=0.0344×7.5×103=258W 89. 附加损耗
铜条转子 Ps*=0.02
Ps= Ps* PN=0.02×7.5×103=150W 90. 机械损耗
二级封闭自扇冷式
Pf w = (3/p)2(D1)4×104= (3/2)2×(0.22)4×104=52.7W 机械损耗标么值
Pfw*= Pf w/ PN=52.7/7.5×103=0.00703 91. 定子铁耗 (1) 定子轭重量
Gt=4pAt1Lt1?Fe2×2.934×10-3×78.81×10-3×7.8×103=14.43㎏ ?=4×(2) 定子齿重量
?=4×Gj=2pAj1Lj1′?Fe2×8.26×10-3×15.97×10-3×7.8×103=4.116㎏
(3) 损耗系数 Phet =6.8 Phej=5.1 (4) 定子齿损耗
25
PFet= K1 Phet Gt=2×5.10×14.43=147.2W (5) 定子轭损耗
PFej= K2Phej Gj =2.5×6.80×4.116=69.97W (6) 定子铁耗
PFe= PFet+ PFej=147.2+69.97=217.17W 对于半闭口槽按经验取 K1=2 K2=2.5 铁耗标么值
PFe*= PFe/ PN=217.17/7.5×103=0.029 92. 总损耗标么值
Σp*= Pcu1* +PAl2* +Pfw* +Ps* +PFe* =0.0347+0.0344+0.02+0.00703+0.029 =0.1251 93. 输出功率
PN1*=1+Σp*=1+0.1251=1.1251 94. 效率
?=1－Σp*/ PN1*=1－0.1251/1.1251=0.869%
(87%－86.9%)/87%=0.115%<0.5% 95. 功率因数
cos?=I1p*/I1*=1.1249/1.294=0.87 96. 转差率
SN==
PAl*****1?PAl2?Ps?PFer?Pfw
0.0344
1?0.0344?0.02?0.0154?0.007=0.0319
PFer*=
=
PFetr?PFeirPN
(1?0.5)?147.2?(1?0.4)?69.97
7.5?10326
=0.0154
97. 转速
nN=(60f/p)(1－SN) =60×50/2×(1－0.0319) =1452r/min 98. 最大转矩倍数
Tm*=
1?SN2(R?(R*1*21?X?))*2
=
1?0.03192?(0.0207?(0.0207?0.131))22
=2.74
(五)起动性能计算
99. 起动电流假设值
Ist′=(2.5~3.5) Tm*Ikw=3×3.157×6.58=59.1A 100. 起动时定转子槽磁势平均值
Fst= Ist′(Ns1/a1)0.707[Ku1+Kd12Kp1(Z1/Z2)](1??0) =59.1×32×0.707×[1+0.95982×1×(36/32)]×0.976
=2836.5A
101空气隙中漏磁场的虚拟磁密
BL=μ0 Fst/2??C
=0.4π×10-6×2836.5/2×0.4×10-3×0.9367 =4.757T
?C=0.64+2.5
?t1?t2
=0.64+2.5=0.9367
0.4
12.3?16.1由BL查得漏抗饱和系数Kz=0.44
27
102齿顶漏磁饱和引起的定子齿顶宽度的减少
CS1=(t1－b01)(1－Kz) =(12.3-3.5)×(1－0.44) =4.93×10-3m
103.齿顶漏磁饱和引起的转子齿顶宽度的减少
CS2=(t2－b02)(1－Kz) =(16.1－1)×(1－0.44) =8.456×10-3m
104.起动时定子槽比漏磁导
?S1(St)=Ku1(?u1－??u1)+KL1?L1
= (0.410-0.185)+ 0.83 =1.055
??h01?0.58h11u1?(b)(CS1)
01CS1?1.5b01=(0.8?0.584.0.924)(934.93?1.5?3.5)
=0.185
105.起动时定子槽漏抗 Xs1(st)* = (
?S1(St)?S1)Xs1*
=(1.055/1.24)×0.440CX =0.3743CX
106.起动时定子谐波漏抗 Xδ1(st)*=KZ Xδ1*
=0.44×0.5877 CX
=0.2586CX
107.起动时定子漏抗 Xσ1(st)*= Xs1(st)*+ Xδ1(st)*+XE1*
=(0.3743+0.2586+0.270) CX
=0.0342
108.考虑集肤效应转子导条相对高度
28