电工学答案（秦曾煌）：dg6

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?6.1?H
^#sZE.,,,,,,,,,,,,,,,,,,,,,,,,3
?6.1.15.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,3
?6.1.25.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,3
?6.1.35.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,3
?6.1.45.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,4
?6.2??
@M?L?è
^.,,,,,,,,,,,,,,,,,,,,,,,,4
?6.2.35.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,4
?6.3?Ma.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,5
?6.3.25.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,5
?6.3.45.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,6
?6.3.65.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,7
?6.4?èHM.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,7
?6.4.15.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,7
1
List of Figures
156.3.4m.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,6
256.3.6m.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,7
2
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6.1HHH
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6.1.1
μBL?

N = 1000,??ü???￥>M?

M?￥?
SFe = 20cm2,M?￥
ü (élFe = 50cm,?1M??á
3HY' =
0:002Wb,
kùL???Y?v￥°
@è
@?
[333]
59
H??<
B = 'S
Fe
= 0:00220￡10?4T = 1T
7a°ü?￥HwL

??m6.1.5
,¤
H = 0:7￡103A=m
?
^ V¤
I = HlFeN = 0:7￡10
3 ￡50￡10?2
1000 A = 0:35A
6.1.2
?T
5￥M??cμBé1– = 0:2cm￥ b#

DM??<°

?
? b#?

HY￥H? ?? V-
{?9

kùL??￥è
@A3v? V
PM??￥H??<?
5?￥
′
$
[333]
NI = HlFe +H0– = HlFe + B0?
0
–
= (0:7￡103 ￡50￡10?2 + 14… ￡10?7 ￡0:2￡10?2)A = 1942A
I = NIN = 19421000A = 1:94A
6.1.3
56.1.1?
?|L??è
@??2:5A

kpM??￥HYb
[333]
H?<
H = NIl
Fe
= 1000￡2:550￡10?2 A=m = 5000A=m
3
V??m6.1.5
U￥HwLb°¤M?¤H??<
B = 1:6T
M??￥HY
' = BSFe = 1:6￡20￡10?4Wb = 0:0032Wb
6.1.4
μBM?L?

ksM??￥H??<aL??￥è
@^
RI2

/
+?f ?/|?M

(1)°
@ ?H
M??
F
L?￥èE
[#è÷èa??
M

(2)?
@ ?H
](1)
(3)?
@ ?H

qè÷èa￥vlh?b
L
!

ò?f ?/yT?HwL￥°L
b?
@ ?H￥f ?/

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è÷èaD??è?
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í?M?
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{Hì?
@bM?
^>
￥
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(
b
[333]
(1)è
@^
?M
'
I = UR ￠PCu = RI2
?Rm = l?S V?
HERmh?
7HY
]NI?M
#HY
' = NIR
m
F
H??<
B = 'S
?Mb
(2)?U … 4:44fN'm = 4:44fNBmS V?
M??￥H??<￥Kv
′Bmh?b
yyT?HwL￥°L

HDB??1
#Hm9h?b?p2NI =
Hml V?
L??è
@Ih?
7^
RI25hl?e ?￥14b
(3) BmaI#RI2 (?Mb
6.2???
@
@
@MMM???LLL???èèè
^
^
^
6.2.3
|BM?L?¤?èaU = 100Va
qf = 50Hz￥??è÷

è
4
@I1 = 5A
cos’1 = 0:7b?|NL??M?
¤?

è÷

5L?
?I2 = 10A
cos’2 = 0:05b
kpNL? μM?
H￥^
M
b
[333]
L?μM?
H￥?
q

P1 = UI1 cos’1 = 100￡5￡0:7W = 350W
L?íM?
H￥?
q

P2 = UI2 cos’2 = 100￡10￡0:05W = 50W
?N VpL?￥èE

R = P2I2
2
= 50102? = 0:5?
L?μM?
H￥^


￠PCu = RI21 = 0:5￡52W = 12:5W
L?μM?
H￥M


￠PFe = P1?￠PCu = (350?12:5)W = 337:5W
6.3MMMaaa
6.3.2
SJL??MMa
?/
SN = 180kV ￠ A
U1N = 10kV
U2N =
400V
f = 50Hz
 ó¤Y=Y0bX?
L???è?
]15:133V
M??

1160cm2b
kp
(1)BQa=Q?F￥

(2)Ma1
(3)BQa=Q?F
￥-?è
@
(4)M??H??<Bmb
[333]
è
^n??m6.3.4(a)
(1)
Up1 = U1Np3 = 10￡10
3
p3 V = 5:78￡103V
N1 = Up1e = 5:78￡10
3
5:133= 1126
Up2 = U2Np3 = 400p3V = 231V
N2 = Up2e = 2315:133= 45
5
(2)
K = U1NU
2N
= 10￡10
3
400 = 25
(3)
I1N = SNp3U
1N
= 180￡10
3
p3￡10￡103A = 10:4A
I2N = SNp3U
2N
= 180￡10
3
p3￡400A = 260A
(4)
Bm = Up14:44fN
1S
= 5:78￡10
3
4:44￡50￡1126￡160￡10?4T
= 1:45T
6.3.4
m1?

{Ma￥=Q?Fμ?Wh
[L¤8?3:5?￥
2

??
r?E F
￥b
kp=Q?F
?s
-1N2N
3
b
[333]
m1:56.3.4m
N
1
N2 +N3
2
￡8 =
N
1
N3
2
￡3:5
N
2 +N3
N3
2
= 83:5
N
2
N3 +1
2
= 83:5
N2
N3 =
r 8
3:5?1 … 1:5?1 =
1
2
6
6.3.6
m2
U￥
^Bè÷Ma
BQ?Fμ550
¤220Vèab=Q?Fμ
?
B?èa36Vaμ36W
B?èa12Vaμ24Wb
??
^BèEμ
b
kpBQè
@I1
?=Q?F￥
b
[333]
m2:56.3.6m
(1)
N1
N2 =
U1
U2 N2 =
U2
U1N1 =
36
220 ￡550= 90
N1
N3 =
U1
U3 N3 =
U3
U1N1 =
12
220 ￡550= 30
(2)
I2 = P2U
2
= 3636A = 1A
I3 = P3U
3
= 2412A = 2A
(3)yi2i3MêM]
#¨/
T9
I1

I1 = N2I2N
1
+ N3I3N
1
= (90￡1550 + 30￡2550 )A
= (0:16+0:11)A = 0:27A
6.4èèèHHHMMM
6.4.1
μB?
@¤(CJ0?10A
L?èa1380V

18750
?L°?
10:09mmb?1¨220Vè÷

ù???

$'9
L?
D¨°?
1
x
ü￥?Lb
[333]
7
(1)?
-a
??M
HYKv′'m???M
(2)'m??M
?
-a
HY
]??M?
(3)è
@D?L?
??1b
?U … 4:44fN'm V?
?'mDf??M
H
UN??1
?
^?
aL?
￥
1
N = 220380 ￡8750= 5066
?
a￥è
@1I
?
-￥è
@1I1
7è
@?1??L?

?
^¤
NI = 8750I1
d2N = (0:09)2 ￡8750
d2 = (0:09)
2 ￡8750
5066 = 0:014
?L°?d = 0:12mm
8
9