ECE 3070 HOMEWORK #1 Spring 2010 DUE: Feb. 1
1. Textbook Problem 2-5.
2. Consider the three phase system shown below consisting of a two three phase loads connected to the source through a line which has an impedance of 0.8+j2.4 . Assume that Vab has an r
ECE 3070
HOMEWORK #1 SUMMER 2002
DUE: MAY 22
1.
Textbook Problem 2-5.
2.
Consider the three phase system shown below consisting of a two three
phase loads connected to the source through a line which has an impedance of
0.8+j2.4 . Assume that Vab has an r
EE 3070
SAMPLE EXAM #3 PROBLEMS
1.
A 30 kVA, 230V (line-line), Y-connected, synchronous motor operates at rated voltage and fullload current at a leading power factor of 0.707. A 3, Y-connected load with an impedance of
4+j3 ? /phase is connected in paral
ECE 3070
HOMEWORK #6
DUE: JULY 22, 2002
1. An 8-pole, 60 Hz, three phase, Y-connected induction machine, rated at 440V, line-line and
850 rpm, has the following equivalent circuit parameters:
R1 = 1.3, R2 = 1.5, X1 = X2 = 0.8, Xm = 12
Assume the machine i
ECE 3070
1.
Homework #3
The resistances and leakage reactances in ohms of a 25-kVA, 60-Hz, 2400:240-V distribution transformer are R2 = 0.00650 R1 = 0.650 Xl1 = 8.40 Xl2 = 0.0840 where subscript 1 denotes the 2400-V winding and subscript 2 denotes the 240
ECE 3070 HOMEWORK #2 FALL 2007 DUE: SEPTEMBER 19
1. A magnetic circuit with a single air gap is shown below. The core dimensions are:
Cross-sectional area Ac = 1.8 x 103 m2 Mean core length = 0.6 m Gap length, g = 2.3 x 10-3 m N = 83 turns
Assume that the
ECE 3070 Sample Exam #1 Problems
1. A magnetic circuit has the following dimensions: A = 16 cm2, length = 40 cm, and N = 360 turns.
The relative permeability of the core is = 50,000. For a magnetic flux density of 1.5 T in the r core, determine, (a) The f
ECE 3070 HOMEWORK #2
Due: June 3, 2002
Textbook Problems 3-8, 3-10 (neglect the leakage flux, l=0),
3-12 (neglect the fringing effect) and
4.) Consider the magnetic structure shown below. All dimensions are given in centimeters. The
permeability of the co
ECE 3070 HOMEWORK #3
Due: June 10, 2002
1. An ac source which can be represented by a voltage source of 5 Vrms in series
with an internal resistance of 3000 is connected to a 150 load resistance
through an ideal transformer.
(a) Calculate the power delive
ECE 3070 HOMEWORK #4
Due: June 26, 2002
1. Suppose three identical transformers are connected as a three phase transformer in Y-. The
transformer is rated at 2400:480 V (Y:). The approximate equivalent circuit parameters of
the transformer referred to the