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 industry, mainly as a motor. Both stator
and rotor car
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 used as three-phase generators in power
systems. Power can
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 superior torque-speed characteristics.
The speed control is
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 moving member will be studied.
Systematic derivation of mat
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 circuit to another through
time-varying magnetic field.
Ap
ECE330
Power Circuits and Electromechanics
Dr. Nam Nguyen-Quang
Spring 2014
http:/www4.hcmut.edu.vn/~nqnam/lecture.php
nqnam@hcmut.edu.vn
Lecture 1
1
Review of power
Assuming sinusoidal voltage and current, i.e.
v(t ) = Vm cos(t + v )
i (t ) = I m cos(t +
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 operation of all
electrical and electromechanical systems.
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 =
I r' =
(R
a
Vap
) (
'
+ R s + j xls + xlr
'
r
)
I = 13
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 20045 0 = 265.5845 0 = 187.79 + j187.79 kVA
3
The per-pha
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)
Text problem 7.25
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 =
cos 1 (0.96 ) = 46.51 16.26 0 A
215
Primary voltage:
I
V
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 (x )
N 2i
lc
r 0 (ad )
2x
0 (a + x )(d + x )
R( x ) 2
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 and 10 , respectively. The transformer is supplying a loa
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). Take into account the effect of fringing in the air gap
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( v i ) = cos( 45 0 ) = 0.7071 leading
2.2
(
)
a) v(t )
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 mWb/m2)
c)
Total flux:
= B A = 1.939 10 3 400 10 6 = 0.
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 area of 400 mm2. If the current through the coil is 6 A,
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 2.8
Text problem 2.9
Text problem 2.10 (Partial answer:
Pre-Lab Assignment 2
1. What is TCP/IP stack? How many layers are in TCP/IP?
TCP/IP is a set of networking protocols which was derived from the former OSI model. It has 4
layers: Link, Internet, Transport and Application. For designing applications in TCP
ECE 5021 Final Exam Solutions (SP/13)
Prob. 1. A common-source stage is shown below with high-frequency components.
(a) Determine the Transfer Function
Vout (s)
Vin (s)
The small signal model of the common-source stage with all of the capacitances is show
ECE 5021 Final Exam
(Due Friday, April 19th, 2013)
1.0 A common source stage is shown below with high-frequency components.
(a) Determine the Transfer Function
Vout (s)
Vin (s)
(b) Simplify the Transfer Function of Part (a) to the form
s
)
Vout (s)
Z
=
s
ECE 5021 Midterm Exam Solutions
Prob. 1. Circuit Specications
Remember, if a transistor is biased, such that the gate is connected to the drain, we have
VGS = VDS = VT +
2IDS
KW
L
a. Internal Slew Rate (V /sec)
SRin =
I5
50A
=
= 107 V /sec = 10V /sec
Cc
5
7ECE 5022 Homework IIIa
Due Date: Wed, October 9, 2013
Note:
1. Consider an RF system with the systems components as shown below
a)
b)
c)
d)
Connect the above components to build a receiver chain with the lowest NF.
Calculate the total NF of the receiver
ECE 5022
Introduction to RF Systems
Lecture 9
Distortion II
Prof. Waleed Khalil
khalil@ece.osu.edu
1
Outline
Harmonic Distortion
Desensitization and Blocking
2nd order Intermodulation
2
Harmonic Distortion
2nd Harmonic distortion, HD2
Amp. of 2nd harm
ECE 5022
Introduction to RF Systems
Lecture 10
Distortion III
Prof. Waleed Khalil
khalil@ece.osu.edu
1
Outline
3rd Order Intermodulation
Linearity of Cascaded Stages
Spurious-free Dynamic Range
2
3rd order Intermodulation, IM3
Gain Compresion
IM3
k1A
3