1. Christopher Barthol
University of Texas, Tyler
Engineering Intern
Electric Ops/Power Quality Group
C5BY@PGE.com
R
V
RANSFORMER
USE
WITCH (N.C.)
APACITOR BANK
OLTAGE REGULATOR
ECLOSER
V
V
R
R
R
V
To San
Andreas
Substation
To San
Angeles
Substation
21 kV
21 kV
12kV
From Ángel Canyon
Power Plant
Rule 2 pertaining to Power Quality…
Service
Voltage
Min
Voltage
Max
Voltage
120V 114V 126V
208V 197V 218V
240V 228V 252V
277V 263V 291V
480V 456V 504V
Alternating Current (AC) shall
be supplied at a frequency of 60
Hertz (each phase completes 60
cycles per second)
Distribution voltage shall
Be within +/- 5% of
nominal service voltage
Voltage balance between phases
shall not deviate more than 2.5%
from each other
Phase A Phase B Phase C Average
Voltage
Voltage
Unbalance
120V 120V 120V 120V 0%
120V 120V 126V 122V 3.2%
240V 237V 245V 241V 1.8%
277V 260V 278V 272 4.2%
475V 482V 480V 479 0.8%
Phase
A
Phase B
Phase
C
This summer I’ve been given the opportunity to spend my time with Pacific Gas and Electric’s very own
Power Quality group. In the past 8 weeks I have learned what power quality engineers do, and the tools
they utilize to ensure that PG&E delivers reliable power to each of its 15 million customers.
SanFierro1116
120V
120V
480V
480V
120V
480V
240V
240V
120V
480V
480V
How this is calculated;
1) Average voltage of all 3 phases
2) Voltage furthest from average – Average
3) [Absolute value of Difference] / Average
= Voltage Unbalance Percentage
WHAT I’VE DONE SO FAR…
Using sophisticated monitoring equipment and
several network resources for monitoring power
within PG&E’s network, I’ve assisted the PQ Group
in investigating customer complaints and trouble-
shooting circuits. I’ve also learned about many of the
components that PG&E’s electrical network consists of
and what it takes to be compliant to “RULE 2.”
SMART METER TECHNOLOGY…
In addition to monitoring equipment and web based info,
the PQ group also uses Smart meters to pro-actively
repair electrical problems. During my time here I have
helped to streamline the process of organizing Smart
Meter data, reducing the time it takes to get repairs
requested and completed.
Transients/Harmonic
Distortion
Momentary Outages
[<5 Mins]
Sustained Outages
[>5 Mins]
Sags & Swells
Electrical Noise
Common
VoltageIssues…
HVAC REAKING HAVOC…
Above is a graph of a customer’s 3 phase system. Their complaint was that they were losing communication
with one of the floors of their building and suspected that it was a power issue. After placing a monitor at the
communications panel that was having issues and monitoring their power for a few days, this data was captured.
Do you notice how there is substantially more activity on Channel 2 than any other? It turns out that the comm
panel was placed on the same phase as the HVAC system for that floor. We suspect that this HVAC load is
disrupting the communication system for that floor.
480V
Down on Jump St…
The Smart Meters at 13, 17,
and 21 Jump St have all been
reporting voltages greater than
10% of nominal for the past few
days. What could be wrong?
Lights Out…
The homeowner at 527 Dessai Rd said his power
Went out momentarily yesterday. He noticed that
something happened at the candy company shortly
before. However, the Courthouse and homes on
Poniente Ct and Lois Ln were fine. What happened?
Not so Sweet…
The owner of the San Fierro
Candy Company is upset. He
says that his VFDs (Variable
Frequency Drives) have
been tripping offline every
weekday morning around
the exact same time. What
might the problem be?
City of San Fierro, CA
Out with the old,
in with the new.
DownonJumpSt:Possiblemalfunctioningtransformer LightsOut:Therecloseractivatedrespondingtoapowersurge NotSoSweet:Possibledefectivecapacitorbank