Download Lab I Critique

Lab I Critique
Theory section should provide basis for all calculations
Comparison of theory to measurement – do the math
Present results & sample calculations in narrative form, in body of report
Computer code goes in appendix, for reference only
Draw Circuit Models
Use admittance when appropriate/convenient.
Your lab report is your vehicle for demonstrating to me, in a clear and
succinct way, that you thoroughly understand the object of the
laboratory activity.
Your grade is a reflection of how well you accomplished that purpose.
The Electric utility acts as a Voltage Source, as opposed to a Current Source.
The utility’s contract with the customer is to provide a standard, specified voltage
at the customer’s connection point.
It is assumed that the customers equipment is designed to operate when provided
with that standard, specified voltage, and that such equipments are connected in
parallel with respect to the internal power network.
Any compensating device placed in series between the utility connection and the
customer equipment will introduce a voltage drop, proportional to total current
drawn. As a result, the customer equipment will not be operating at its specified
design voltage.
Any compensating device placed in parallel with the utility connection will draw
a current, but will not materially affect the voltage available to the customer
equipment. This why power factor compensators are installed in parallel with the
utility connection.
Comment: If the utility infrastructure had been developed to act as a current
source, customer equipment, as well as compensation devices, would have to be
connected in series. Think about the practical problems associated with such a
scheme.
So….
Loads are connected in parallel, compensators are connected in parallel. Which
would be the more convenient way to conceptualize the load when dealing with
utility and/or power factor correction applications?
Impedance
Admittance
This conflicts with
towards
Hint!our instinctive prejudice
Hint!
seeing all circuits in terms of impedance . . . .
. . . doesn’t it?
In the future, I will make engineering decisions based on:
Prejudice
Rational Thought
Reber/Bujnowski Data:
S=
P=
V=
check
I=
pf =
check
f=
w=
705.930 W
5.864 VA
540.257 W
454.378 W
1.206 hy
922.407 W
1096.746 W
-9.12E-04 s
2.912 hy
|Z| =
Q=
Rs =
Xs =
Ls =
Rp =
Xp =
Bp =
Lp =
9.11 VA
6.972 w
80.3 v
80.19 v
0.1136 A
0.7649 Lagging
0.7653
59.94 hz
376.6 r/s
7.0
Cp* =
Bp* =
Cp =
Xc =
Bc =
BT =
Q' =
Phase:
pf =
2.42E-06 F
9.12E-04 s
3.98E-06 F
-667.816 W
1.50E-03 s
5.86E-04 s
-3.77E+00 VA
0.4953 rad
0.880 Leading
6.0
5.0
4.0
3.0
2.0
1.0
Ideal
0.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
Before
7.0
-2.0
-3.0
-4.0
-5.0
-6.0
Measured: 0.843 Leading
8.0
After
Measured