Revinal Dela Rosa
Education:
● Master of Science in Electric Power System engineering
(North Carolina State University) - 2020
● Bachelor of Science in Electrical Engineering
(Bulacan State University) - 2003
Licenses:
● Professional Engineer in New York, California, Texas, North
Carolina, Tennessee, Washington, Alabama, Pennsylvania (Sign and
seal)
● Registered Electrical Engineer - Philippines (Expired)
● Registered Master Electrician - Philippines (Expired)
Standard:
● Working group/co-author “IEEE Guide for the Design of Low-Voltage
Auxiliary Systems for Electric Power Substation” IEEE Std. 1818-
2017
Notable Projects
● Vietnam Omon Thermal Power Plant
Lead Electrical and Instrumentation Construction Design Engineer
(Assigned in Nagasaki, Japan for 2 years and in Vietnam <year)
● 230kV/115KV Embarcadero and Potrero Substation
(Supplying more than 60% of downtown San Francisco California,
USA)
Lead Electrical Engineer who Signed and Sealed the Electrical
Design drawings & calculations and consider as Engineer in Record
● Project Lead Engineer who supported Google in creating
Specifications on High Voltage Substation Equipments to be used in
their Data Centers.
● Working now in some projects of US Government.
High voltage substation (basic) &
ac & dc auxiliary system
calculation guide
By: Revinal Dela Rosa PE, MSEPSE
Overview:
1. Generation, transmission, distribution background
2. HV Substation
3. HV equipments
4. HV bus configurations
5. Factors affecting design and engineering of HV
substation
6. Basic calculations HV equipments
7. AC and DC auxiliary system calculation
● Power
Generation ● Generation Step- ● Transmission
DER up Transformer Line
● Customers ● Distribution
Source: https://kiewit.com/markets/power/ ● Distribution Substation
DER
Source: https://en.wikipedia.org/wiki/Electric_power_transmission
Substation
● Transmission
Substation
● Distribution
Substation
● AIS and GIS
AIS
“Air Insulated
Substation”
GIS
“Gas insulated
switchgear”
Substation Equipments
● Transformer
● Breaker
● Switch
● Surge Arrester
● Potential
Transformer/CCVT
● Current Transformer
Source: pfiffner, ABB, Siemens
Bus Configuration
Source: IEEE
Bus Configuration
Source: IEEE
Bus Configuration
Xfmr 1 Line 1
Line 2 Xfmr 2
Source: IEEE
Bus Configuration
Xfmr 1
Xfmr 2
Line 2
Line 1
Source: IEEE
Bus Configuration
Source: IEEE
Bus Configuration
Factors Affecting the Design and Engineering
Physical
-Spacing and Clearances (ANSI C29.8 & 29.9, NESC,
IEEE 1427-2006, NFPA 70E), To check Client Standard
(Utility or Industrial clients)
Structural
-Applied forces (Wind, Ice, Short Circuit) (IEEE 605-Rigid
Bus), To check Client Standard
Protection, Control and Automation
-Type of communication Protocol (Modbus, DNP3 or
IEC61850)
-Do we need redundancy? How many Panels we need?
Do we need MIMIC Panel? What is the existing P&C and
Automation set up? Security??
Basic Calculation in Substation
Main Transformer (3 phase)
Legend:
VA = (√3) x VL x IL MVA : Mega Volt Amp
VL : Line Voltage
IL : Line Current
1. What is the minimum Transformer size given the
Line Voltage equal to 115kV and Line Current of
600 A?
119.5 MVA
MVA Base
First Stage Fan is on
Source: Augusta RFP 2nd Stage Fan is on
Basic Calculation in Substation
HV CB & Disconnect Switch rating Legend:
MVA : Mega Volt Amp
HV CB rating (IL) = 1.25 x VA / [(√3) x VL] VL : Line Voltage
IL : Line Current
Safety factor
1. What is the rating of HV Breaker given the Line
Voltage equal to 115kV and protecting the
158MVA Transformer?
Source: pfiffner, ABB, Siemens
991A
Source: Augusta RFP
Basic Calculation in Substation
KAIC (kiloampere interrupting
capacity) Calculation
Considering Infinite Bus
I short Circuit = MVA base Base Rating
(√3) x VL x %Z
1. What is the KAIC rating of the breaker of
secondary side of Transformer having
impedance of 10%?
Source: pfiffner, ABB, Siemens
19 kA
Source: Augusta RFP
Surge Arrester
Source:
http://www.arresterworks.com/ArresterFacts_files/ArresterFacts%2
0016%20Selecting%20Arrester%20MCOV-Uc.pdf
Current Transformer:
Minimum size:
Primary Winding = Full Load Current
Secondary winding = 5A
Note: Need to verify to P&C, P&C need to consider CT matching, burden and
short circuit considering.
Example size : 600/5A, 1200/ 5A, 3000/5A
Potential Transformer/ CVT,
CCVT:
Minimum size:
Primary Winding = Line to Ground Voltage (HV system)
Secondary winding = 115V
Note: Need to verify to P&C, P&C need to consider system requirement
Example size :
Auxiliary Systems of High
Voltage Substation
AC & DC
What do we need?
1. Main Single Line Diagram/Single Line and Metering Diagram
Includes all the electrical equipments such as:
a. Breaker
b. Transformer
c. Relay
d. Current Transformer
e. Potential Transformer
2. Lay-out of Substation (lighting, equipments, receptacles)
What do we need?
3. Need to identify the DC Loads
a. Charging Motor of Circuit Breaker
b. Trip/close coil of Circuit Breaker
c. Lockout relay
d. Relay
e. Communication
4. Need to identify the AC Loads
a. Heaters of Circuit Breakers, Potential Transformers, Current
Transformers
b. AC Loads of Transformer
c. Lighting, HVAC, receptacles etc.
HV Substation Lay out
From http://www.quad3.com/69kv-13-2kv-substation-feasibility-design.php
Building Layout
Catalogue Sheets
In order to get the AC Loads,
we need to get the DC loads
first.
Are we going to include and
get the sum of all the DC
loads?
The answer is “No”, but we
need to create a different
scenarios and simulate the
location of the faults and
look where there will be the
highest consumption of DC
loads.
Worst Case scenario
Creating a load profile
Creating a load profile
Calculation of Battery/DC
Loads:
Source: IEEE std 485-1997
Simulation example:
Simulation Result:
Factors in Battery sizing:
1. Voltage
2. Amp Hour (Capacity)
3. Depth of Discharge
4. Physical size
5. Location
6. Temperature
Calculation of AC loads:
Factors in AC Aux
1. Voltage (Phase- Single Phase, Three
Phase)
2. Ampere
3. KAIC
4. Connection of the Transformers
(Wye-Delta?)
5. Location (NEMA 1, NEMA 3R)
6. Temperature
7. Brown field/Green field Substation
Thank you for Listening!
Keep safe and God Bless!
revinald_77@yahoo.com
