ECE330 Spring 2014
Problem 1 (60 pts)
i
a
a
a
N
Depth d into page
Riron
Ni
g
x
Rgap
a
Riron =
lc
R gap =
r 0 (ad )
2x
(x < a, d)
0 (a + x )(d + x )
R ( x ) = Riron + R gap
a)
N 2i
=
=
R(x )
Ni
=
R (
ECE 330 homework assignment #3, due on Friday, March 21, 2014
Problem 1
A 15 kVA, 2200/220 V transformer has Rc = 195 and Xm = 170 referred to the LV side. Req
and Xeq referred to the HV side are 6 an
ECE330 Spring 2014
Problem 1
+ I1
V1
Req
Rc
I2/a
jXeq
V2
jXm
Load
_
10:1
Turns ratio a = 2200/220 = 10.
Rc' = a 2 Rc = 19500
'
X m = a 2 X m = 17000
Assume V2 = 2150 0 V,
Load current:
10000
I2 =
c
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
Lecture 2
1
Introduction
Electromagnetic theory: basis for explaining the operati
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
[email protected]
Lecture 1
1
Review of power
Assuming sinusoidal voltage and cu
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
Lecture 3
1
Transformers Introduction
Transferring electrical energy from one cir
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
Lecture 4
1
Electromechanical system Introduction
Magnetic circuits with one movi
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
Lecture 9
1
DC machines Introduction
DC machine is a versatile device having supe
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
Lecture 7
1
Synchronous machines Introduction
Synchronous machines are mainly use
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
Lecture 8
1
Induction machines - Introduction
The most widely used machine in the
ECE330 Spring 2014
7.5
Rr' 0.048
=
= 1.6
s
0.03
a)
440
0 = 2540 , the rotor current referred to stator side is
3
2540
=
= 146.02 17.39 A
(0.06 + 1.6) + j (0.26 + 0.26)
Assuming phase voltage is Vap =
ECE330 Spring 2014
6.2
Total per-phase complex power is
S Tp = (1500 + j 300) 3 = 500 + j100 kVA
Assuming VaLp = VaMp = VaLp 0 0 , the per-phase load complex power is
*
S Lp = VaLp I aLp =
2300
0 0 20
9
Bi-Directional Search
Ira Pohl*
Thomas J. Watson Research Center
I B M Corporation, New York
Abstract
A technique that has proved useful in shortest path and other discrete
optimization computations
ECE 330 homework assignment #1, due on Friday, February 21, 2014
Text problem 2.1 (Partial answer: 0.707 leading)
Text problem 2.2 (Partial answers: -250, -500, 500, 0, 150, 1900, -150)
Text problem 2
ECE 330 homework assignment #2, due on Friday, March 7, 2014
Problem 1
A coil of 180 turns is wound uniformly over a wooden ring having a mean circumference of 700
mm, and a uniform cross sectional ar
ECE330 Spring 2014
Problem 1
A wooden ring would have the permeability of the air.
a)
Magnetic field strength:
NI 180 6
H=
=
= 1543 (A/m)
l
0 .7
b)
Flux density:
B = 0 H = 4 10 7 1543 = 1.939 (mT or m
ECE330 Spring 2014
2.1
(
)
v(t ) = 100 cos 377t + 10 0 V => V =
(
)
i (t ) = cos 377t + 55 0 A => I =
1
2
100
2
10 0 V
55 0 A
Average power: P = VI cos( v i ) =
100 1
(
)
(
2 2
Power factor: PF = cos(
ECE 330 homework assignment #4, due in Mid-term examination
Problem 1
For the magnetic circuit in Fig. 1 below, the upper part with winding is fixed, and the lower part is
movable (up and down only).
ECE 330 homework assignment #6, due on Friday, May 30, 2014
Text problem 7.5
Text problem 7.16 (Use the exact equivalent circuit)
Text problem 7.17
Text problem 7.22 (Use the exact equivalent circuit)
Applications of Search
hy?
Fast computation
Better bounds (depending on landmark) than simple Euclidean
Distance
Depending on the landmark, heuristic cost can be 0!
Images from Goldberg (2011), Re
a f