Transcript Power Distribution: Load Flow Project

Objective



Provide an analysis of the existing
Waltz-Mill system.
Determine the affect on the system
of adding an additional motor load.
Determine the necessary changes to
safely add the new load and increase
the power factor on T6 and T7.
Existing System Analysis
With SKM Power Tools Software

A Load Flow
analysis was
performed with the
following data.
Location
Load
PF
T1
1300kVA .8
T2
1275kVA .8
BKR2
416.71k
Va
BKR3
No load
.8
BKR5
306kVA
.8
T10
568kVA
.8
BKR15
450.75k
VA
.8
T11
220kVA
.8
BKR10
225.81k
VA
.8
BKR13
375.89K
VA
.8
Existing System Analysis
With SKM Power Tools Software

The following values will be found
under the current conditions
• Percent loading for each feeder circuit
• Percent loading for each transformer
• Nominal voltage and percent voltage
drop at each switchgear
• Optimal transformer taps
System Analysis with new load



500hp motor load added to
secondary bus T7.
Determine the size of the cable and
breaker.
Increase power factor on secondary
bus of T6 and T7 to .97 by adding a
capacitor bank.
Results and Recommendations


Load flow analysis
of existing system
before tap
optimization.
Includes percent
loading for all
transformers and
feeders.
Results and Recommendations

Tap settings were
optimized to
minimize loss in
the system.
Load Flow results with optimized
tap settings
Results and Recommendations



The full load ampacity
for the motor was
found with the
equation for FLA.
The breaker was sized
at 125% FLA.
The size of the
capacitor bank needed
to improve the PF to
.97 was found with
the equation for QB.
Added motor and capacitor
bank to T7
Results and Recommendations
Added capacitor bank to
correct T6 power factor to
0.97
Results and Recommendations




The motor drew up to
683.92A
3-1/C, 500MCM,
nonmagnetic cable was
chosen (ampacity of
810A)
A GE SK, Spectra motor
circuit protector with trip
settings between 6001200A was selected.
This trip current
should be set to 800A.
Load flow analysis of system
with motor and capacitor
banks added