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2013 Life of a Transformer™ Seminar
February 18-21, 2013
San Diego, California USA
Seismic Qualification
Requirements for Transformers
Travis Soppe, PE – W.E. Gundy & Associates Inc.
Mathew Brien – SPX Transformer Solutions, Inc. © Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 2
• Seismic Hazard Awareness
• Specifications Defining Seismic Design Requirements
– IEEE-693-2005
– IBC-2009, CBC-2010, ASCE/SEI 7-10, and UBC 1997
– IEEE C57.114-1990
• Seismic Strengthening Techniques
– Anchorage
– Core and Coil Restraint (Load Path)
– Appendage Bracing (Radiators, Conservator, Controls, Arresters)
– Bushings and Surge Arresters
OVERVIEW
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 3
• Recent Earthquakes Serve as Reminders
– January 12, 2010: Magnitude 7.0 – Haiti
– February 27, 2010: Magnitude 8.8 – Chile
– April 4, 2010: Magnitude 7.2 – Baja California, Mexico
– March 13, 2011: Magnitude 9.0 – Honshu, Japan
– April 13, 2011: Magnitude 5.8 – Virginia
– June 13, 2011: Magnitude 6.0 – Christchurch, New Zealand
– November 06, 2011: Magnitude 5.6 – Oklahoma
Seismic Hazard Awareness
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 4
Seismic Hazard Awareness
Magnitude Location and Date Magnitude Location and Date Magnitude Location and Date
6.8 VANUATU December 21, 2012 6.6 MOLUCCA SEA August 26, 2012 6.9 GULF OF CALIFORNIA April 12, 2012
7.1 BANDA SEA December 10, 2012 6.3 SULAWESI, INDONESIA August 18, 2012 6.5 MICHOACAN, MEXICO April 11, 2012
6.3 NEW ZEALAND December 07, 2012 7.7 SEA OF OKHOTSK August 14, 2012 5.9 OREGON April 11, 2012
7.3 HONSHU, JAPAN December 07, 2012 6.4 NORTHWESTERN IRAN August 11, 2012 8.2 NORTHERN SUMATRA April 11, 2012
6.4 KURIL ISLANDS November 16, 2012 6.5 PAPUA NEW GUINEA July 28, 2012 8.6 NORTHERN SUMATRA April 11, 2012
6.5 GUATEMALA November 11, 2012 6.7 MAURITIUS - REUNION REGION July 26, 2012 7.1 MAULE, CHILE March 25, 2012
6.8 MYANMAR November 11, 2012 6.5 SOLOMON ISLANDS July 25, 2012 6.6 PAPUA NEW GUINEA March 21, 2012
4.3 EASTERN KENTUCKY November 10, 2012 6.4 SIMEULUE, INDONESIA July 25, 2012 7.4 OAXACA, MEXICO March 20, 2012
7.4 GUATEMALA November 07, 2012 5.2 NORTHERN CALIFORNIA July 21, 2012 6.9 HONSHU, JAPAN March 14, 2012
7.7 QUEEN CHARLOTTE October 28, 2012 5.1 NORTHERN CALIFORNIA July 21, 2012 6.7 VANUATU March 09, 2012
6.5 COSTA RICA October 24, 2012 5.7 AFGHANISTAN June 11, 2012 4 BAY AREA, CALIFORNIA March 05, 2012
5.3 CENTRAL CALIFORNIA October 21, 2012 6.4 PANAMA June 04, 2012 6.6 LOYALTY ISLANDS March 03, 2012
6.2 VANUATU October 20, 2012 6.2 PANAMA June 04, 2012 6.7 SIBERIA, RUSSIA February 26, 2012
6.7 PAPUA, INDONESIA October 12, 2012 6.7 ARGENTINA May 28, 2012 6 OREGON February 15, 2012
6.4 ALEUTIAN IS., ALASKA September 26, 2012 5.6 BULGARIA May 22, 2012 6.4 SOLOMON ISLANDS February 14, 2012
5.6 CHINA September 07, 2012 6.7 TONGA April 28, 2012 5.6 NORTHERN CALIFORNIA February 13, 2012
7.6 COSTA RICA September 05, 2012 6.6 PAPUA, INDONESIA April 21, 2012 6.7 PHILIPPINES February 06, 2012
7.6 PHILIPPINE ISLANDS REGION August 31, 2012 6.8 PAPUA NEW GUINEA April 17, 2012 7.1 VANUATU February 02, 2012
6.8 JAN MAYEN ISLAND REGION August 30, 2012 6.7 CHILE April 17, 2012 6.3 CENTRAL PERU January 30, 2012
7.3 OFFSHORE EL SALVADOR August 27, 2012 6.5 VANUATU April 14, 2012 - Data obtained from USGS -
Major Earthquakes in 2012 - USGS
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 5
USGS National Seismic Hazard Map
Seismic Hazard Awareness
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 6
Seismic Hazard Awareness
Transformers will be Subjected to Seismic Loads
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 7
• Commonly Specified Standards for Seismic Qualification
– IEEE-693-2005: Recommended Practice for Seismic Design of Substations
– ICC IBC-2009: International Building Code
– CBC-2010: California Building Code
– ASCE/SEI 7-10: Minimum Design Loads for Buildings and Other Structures
– UBC 1997: Uniform Building Code
– IEEE C57.114-1990: Seismic Guide for Power Transformers and Reactors
Transformer Seismic Design Specifications
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 8
• IEEE 693-2005
– Specifically Developed for Seismic Design of HV Substation Equipment
– Standardize an Approach to Qualification of Equipment
– Working Group Consisting of
• Public Utility Engineers
• HV Equipment Manufacturing and Design Engineers
• Civil, Structural and Electrical Engineering Consultants
• Academics
Transformer Seismic Design Specifications
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 9
• ICC IBC-2009, CBC-2010, UBC 1997, ASCE/SEI 7-10
– Specifically Developed for Building Design (all types of loading)
– Standard Approach to Seismic Design of Buildings and Associated
Mechanical and Electrical Equipment
– Working Group Consisting of
• Public Building Officials
• Academic and Research Engineers
• Civil, Structural, Mechanical, and Electrical Engineering Consultants
Transformer Seismic Design Specifications
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 10
• IEEE C57.114-1990
– Specifically Developed for Transformers and Reactors
– Standardize Approach to Seismic Design of Transformers and Reactors
– Working Group Consisting of
• Public Utility Engineers
• HV Equipment Manufacturing and Design Engineers
• Civil, Structural and Electrical Engineering Consultants
• Academics
Transformer Seismic Design Specifications
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 11
• Use IEEE 693-2005
– Designed Specifically for HV Substations
– Provides Standardized Methodology for
Seismic Qualification of Equipment
– Reduces Overlap and Expense of Seismic
Qualification for Manufacturers and
Utilities
Transformer Seismic Design Specifications
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 12
• Provide a set of standard methods that can be used by
manufacturers to seismically qualify substation equipment
and support structures
• Provide a number of standard qualification levels to be used
for qualification
• Manufacturers only have to seismically qualify equipment
once such that it can be sold to multiple Private/Public Utilities
without overlap (less typical for large power transformers)
IEEE 693-2005 Purpose
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2013 Life of a Transformer™ 13
• Qualification Levels are Based on the Site PGA – Seismic Hazard: Proximately to active faults – Ss (ASCE/SEI 7-10)
– Site Soil Conditions: Soil properties can amplify loading - Fa (ASCE/SEI 7-10)
– ASCE/SEI 7-10 Values to Calculate PGA = 0.4*SMS = 0.4*Fa*Ss
• Three Qualification Levels for Different Site Characteristics
IEEE 693-2005 Qualification Levels
Peak Ground Acceleration IEEE Qualification Level Static Design Acceleration
for Transformers
PGA ≤ 0.1g Low NA
0.1g > PGA ≤ 0.5g Moderate 0.25g
0.5g < PGA High 0.50g
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2013 Life of a Transformer™ 14
• Selection of Qualification Levels – Seismic Hazards of Service Area in Consideration
– Type, Rating, and Size of Transformer
• Can the transformer be easily moved and utilized at many locations or will the
transformer be at a fixed location.
– Risk Management Strategies of Operating Utility
• Seismic Hazards are predictions and the earthquake can be higher / lower than
the design earthquake
• Identify risk associated with loss of transformer during seismic event
IEEE 693-2005 Qualification Level Selection
Peak Ground Acceleration IEEE Qualification Level
PGA ≤ 0.1g Low
0.1g > PGA ≤ 0.5g Moderate
0.5g < PGA High
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2013 Life of a Transformer™ 15
• “LOW” Level Qualification – Full analysis and report is not required
– Ensure CNC has a well defined load path
– Analyze anchorage for combined 0.20g horizontal and 0.16g vertical load.
• “MODERATE” Level Qualification
– Full analysis (load path or static based on kV) and report is required
– 0.25g Horizontal Load and 0.20g Vertical Load (load path members)
• “HIGH” Level Qualification
– Full analysis (load path or static based on kV) and report is required
– 0.50g Horizontal Load and 0.40g Vertical Load (load path members)
IEEE 693-2005 Qualification Levels
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2013 Life of a Transformer™ 16
• Requirements Transformers with kV Ratings < 35kV
– Inherently Acceptable – Less Vulnerable to Seismic Loads
– Full analysis and report is NOT required
– Inherently Acceptable Requirements
• Document/Define Load Path of CNC – No Calculations
• Anchorage Analysis
– Same Acceleration Values for Moderate and High Level
– 1.0g in most vulnerable horizontal direction
– 0.80g in vertical direction
IEEE 693-2005 Qualification – kV < 35 kV
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2013 Life of a Transformer™ 17
• Transformers with kV Ratings ≥ 35kV and < 115kV
– Qualified by Load Path Analysis • Develop Seismic Loads from the Core and Coil through the tank to the
anchorage and evaluate these members
• Include loads from appendages (radiators, conservators, ect.) but evaluation of
appendages is not required
– Acceleration Levels for Analysis
• 0.5g High Level Horizontal Load or 0.25g Moderate Level Horizontal Load
• 0.4g High Level Horizontal Load or 0.20g Moderate Level Horizontal Load
• Combine resulting stresses from the two horizontal directions with vertical
direction using square root of the sum of the squares SRSS method
IEEE 693-2005 Qualification – 35 ≤ kV < 115
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2013 Life of a Transformer™ 18
• Load path free body diagram (IEEE 693-2005) and
model showing load path of core and coil
IEEE 693-2005 Qualification – 35 ≤ kV < 115
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2013 Life of a Transformer™ 19
IEEE 693-2005 Qualification – 35 ≤ kV < 115
Evaluate Stress in CNC Restraint, Tank Walls, and Anchorage
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 20
• Transformers with kV Ratings ≥ 115kV
– Qualified by Static Analysis • Develop Seismic Loads from the Core and Coil through the tank to the
anchorage and evaluate these members
• Include loads from appendages (radiators, conservators, ect.)
• Evaluate appendages using 3 times static seismic loads
• Radiators required to be braced horizontally and vertically to the tank side wall
– Acceleration Levels for Analysis (High/Moderate)
• Load Path Members - 0.5g/0.25g Horizontal and 0.4g/0.20g Vertical Load
• Appendages – 1.5g/0.75g Horizontal and 1.2g/0.60g Vertical Load
• Combine resulting stresses from the two horizontal directions with vertical
direction using square root of the sum of the squares SRSS method
IEEE 693-2005 Qualification kV ≥ 115kV
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2013 Life of a Transformer™ 21
Load Path Members
Appendages - 3 times loading.
IEEE 693-2005 Qualification – kV ≥ 115kV
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 22
Evaluate Stress in CNC Restraint, Tank Walls, Appendages, and Anchorage
IEEE 693-2005 Qualification
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 23
• Building Codes developed for design of buildings, building
type structures, and equipment located in buildings.
• ICC IBC-2009 replaces outdated UBC1997 code
• CBC-2010 has similar requirements to ICC IBC-2009
• ASCE/SEI 7-10 is used by both ICC IBC-2009 and CBC-2010
for developing seismic loads - Focus on ASCE/SIE 7-10
• Discussion on Building Codes Shall Cover
– Seismic Hazards (Current ASCE/SEI 7-10 and past UBC 1997)
– Transformer Qualification Methods (testing or analysis)
ICC IBC-2009, CBC-2010, ASCE/SEI 7-10, UBC 1997
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 24
• Hazard Maps developed by USGS identify accelerations for
Maximum Considered Earthquake (SS – used for transformers)
ASCE/SEI 7-10 Seismic Hazards
http://geohazards.usgs.gov/designmaps/us/application.php
© Doble Engineering Company
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2013 Life of a Transformer™ 25
• Calculation of Site Specific Design Earthquake Spectral
Response Acceleration Parameter SDS
– Short Period Spectral Acceleration from Hazard Maps Ss (3.75g max)
– Adjust SS for soil conditions using Fa
– Assume site class D if soil properties are unknown, then Fa ranges
from 1.0 to 1.6 depending on SS.
• SDS is used to develop loading to the transformer according to
either Chapter 13 or Chapter 15 of ASCE/SEI 7-10
ASCE/SEI 7-10 Seismic Hazards
𝑆𝐷𝑆 =2
3𝑆𝑆𝐹𝐴 © Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 26
• Seismic Design Requirements for Nonstructural Components
– Determine Importance Factor IP for the Transformer (IP = 1.5 or 1.0)
– IP = 1.5 for Transformers essential to the functionality of a Risk
Category IV structure or required for life-safety purposes after and EQ
– IP = 1.0 for all other Transformers qualified according to Chapter 13
• Shake Table Testing Required for Transformers with IP = 1.5
– Testing shall follow guidelines of ICC-ES AC156
– Testing more typical on distribution transformers
– Typically test most seismically vulnerable transformers to qualify an
entire product line of transformers
• Analysis Required for Transformers with IP = 1.0
ASCE/SEI 7-10 Transformer Loading: Chapter 13
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2013 Life of a Transformer™ 27
– Test to verify electrical
functionality before and
after a seismic event
– Functionality can’t be
verified by analysis
– Perform the same factory
tests on the transformer
that would be performed
prior to shipping the unit
ASCE/SEI 7-10 Transformer Loading: Chapter 13
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 28
• Seismic Design Load Calculation (FP) for Analysis of
Transformers with IP = 1.0
ASCE/SEI 7-10 Transformer Loading: Chapter 13
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 29
• Seismic Design Requirements for Nonbuilding Structures
– Importance factor Ie can be 1.0, 1.25, or 1.5 and is used to amplify
loading to the transformer (no testing requirements).
• Seismic Design Base Shear (V) for Analysis assuming the
transformer acts as a rigid nonbuilding structure
• Seismic loads (V) are distributed relative to the
height of the transformer not applied at the
CG as done in Chapter 13
ASCE/SEI 7-10 Transformer Loading: Chapter 15
𝑉 = 0.3𝑆𝐷𝑆𝐼𝑒 © Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 30
• Many specifications call out seismic zones as defined in UBC
UBC-1997 Seismic Hazards
Map from UBC - 1997
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2013 Life of a Transformer™ 31
• Need to Determine Seismic Coefficient Ca for Analysis
UBC-1997 Seismic Hazards
Tables from UBC - 1997
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2013 Life of a Transformer™ 32
• 1632 – Nonstructural Components (testing not required)
UBC-1997 Transformer Loading: Section 1632 or 1634
𝑉 = 0.7𝐶𝑎𝐼
• 1634 – Nonbuilding Structures
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 33
• Developed specifically for Transformers and Rectors
• IEEE 639-2005 qualification will meet C57.114-1990
objectives and requirements
• Seismic Hazards identified for site specific according to UBC
• Techniques for qualification in the standard include
– Shake table testing (preferred qualification method)
– Analysis (when testing is deemed impractical)
– Rail Shipment Test
• Instrument the transformer during shipment and show that the loading and
stresses due to transport are equivalent to seismic loading
• Ensure transformer meets certain performance objectives
IEEE C57.114-1990 Seismic Requirements
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2013 Life of a Transformer™ 34
• When writing your specification, be specific!
• Is a report required?
• What standard needs to be met?
– IEEE 693-2005 – What qualification level needs to be met
– ICC IBC-2009, CBC-2010
– UBC-1997 – Specify the current standard ICC IBC-2009
– IEEE C57.114-1990 – Specify the current standard IEEE 693-2005
• Stating the site conditions alone is not sufficient information
Preparing Specifications for Seismic Conditions
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2013 Life of a Transformer™ 35
• Examples of IEEE 693-2005 Specification
Preparing Specifications for Seismic Conditions
• Remember when specifying timelines, that your transformer is unique, and so is the
seismic qualification report. The report cannot be completed before the design and
drawings are finalized.
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 36
Seismic Design Considerations
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2013 Life of a Transformer™ 37
There are several aspects of
transformer and substation
design to consider for seismic
areas
• Anchorage
• Internal Locking
• Radiator Bracing
• Conservator Support Bracing
• Bushings and Arresters
Seismic Design Considerations
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 38
Seismic Design Considerations
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 39
• Ensuring a unit is properly
anchored is an extremely
effective way to reduce the
probability of damage during an
earthquake
• Anchorage should be designed
for the seismic forces and take
into account the transformer
weight and geometry
• Base shear and overturning
moments should be evaluated
for the worst case direction
Seismic Design Considerations: Anchorage
Sherman – NISEE / EERC
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 40
Seismic Design Considerations: Anchorage Forces
Steinbrugge Collection – NISEE / EERC
Steinbrugge Collection – NISEE / EERC
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 41
Seismic Design Considerations: Transformers on Rails
Whittaker – NISEE / EERC
Whittaker– NISEE / EERC
Fierro - PEER
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2013 Life of a Transformer™ 42
• Welded Anchorage (Preferred) – The base of the
transformer is welded directly to members embedded in the
foundation
• Bolted Anchorage
– Cast in place anchorage: Anchor rods are embedded in the
concrete foundation. Typically have higher strength capacity
– Post Installed anchorage: Mechanical anchors or epoxied
anchors placed in drilled holes. Easier to install but typically have
lower strength capacity which is challenging for large power
transformers.
• Anchor Clips – The base is held in place by clips which can
either be bolted or welded to the foundation
Seismic Design Considerations: Anchorage Methods
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2013 Life of a Transformer™ 43
• Welding is the preferred
method of anchorage due
to excellent field
performance
• Requires steel embedded
in the foundation
• Typically not an option on
older retrofit foundations
Seismic Design Considerations: Welded Anchorage
Steinbrugge Collection – NISEE / EERC
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 44
• If welding to the base is
not possible, a bolted
anchorage may be used
• Allows for mobility and
retrofit to existing bases
• Can use embedded
studs for greater strength
Seismic Design Considerations: Bolted Anchorage
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2013 Life of a Transformer™ 45
• Anchor clips can be
bolted to the foundation,
or welded to imbed
plates
• Allows for flexibility in
anchorage location for
retrofits and ease of
installation
• Clips should be designed
to restrict vertical
movement
Seismic Design Considerations: Anchor Clips
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2013 Life of a Transformer™ 46
• Internal Locking is
required to ensure the
active part of the
transformer does not
shift during a seismic
event
• Typically a standard
design which meets
shipping requirements
is sufficient to resist
seismic forces
Seismic Design Considerations: Internal Locking
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2013 Life of a Transformer™ 47
• Brace radiators to restrict movement which
may cause damage to the panels and
leakage at joints
• Bracing limits moment demands on
radiator valve pipes
• Bracing should resist movement in the
horizontal and vertical directions and limit
loading to radiator valve connections
• Bracing is required per IEEE 693 for
transformers with kV ratings > 115
• Standard designs for high wind areas will
be insufficient to resist high seismic forces
Seismic Design Considerations: Radiator Bracing
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2013 Life of a Transformer™ 48
Seismic Design Considerations: Radiator Bracing
Braced and Unbraced Radiator Bank Subjected to Seismic Loading
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2013 Life of a Transformer™ 49
Seismic Design Considerations: Radiator Bracing
• Moment demand on radiator valve pipe and connection is significantly
reduced when bracing is added (previous video, IEEE time history)
• Detail bracing to withstand lateral loading from the radiator bank, brace
member and connection should have equivalent capacities
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2013 Life of a Transformer™ 50
Seismic Design Considerations: Conservator Bracing
• Conservators are vulnerable to
earthquake loading due to their
significant mass and height above
the transformer
• Bracing adds stiffness and reduces
seismic response of conservator
• Detail piping to transformer to allow
for differential displacements
between the conservator and tank
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 51
Seismic Design Considerations: Conservator Bracing
Braced and Unbraced Conservator Subjected to Seismic Loading
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2013 Life of a Transformer™ 52
Seismic Design Considerations: Conservator Bracing
• Moment demand on conservator support and connection is significantly
reduced when bracing is added (previous video, IEEE time history loading)
• Detail bracing to withstand lateral loading from the conservator, brace
member and connection should have equivalent capacities
© Doble Engineering Company
©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 53
Seismic Design Considerations: Conservator Bracing
• Stresses in conservator and support are significantly reduced when
bracing is added (previous video, IEEE time history loading)
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 54
• Typical construction with heavy brittle
porcelain material
• Use of polymers is becoming more
popular, better seismic performance
• Failures often due to line loading or
amplified support loading (flexible
support conditions)
• Bushings and arresters should be
qualified to meet the requirements of
IEEE 693 (testing required)
• Evaluate supporting elements of the
transformer to ensure sufficient
strength and rigidity
Seismic Design Considerations: Bushings and Arresters
Northridge – NISEE / EERC
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©2013 Doble Engineering Company. All Rights Reserved
2013 Life of a Transformer™ 55
500kV Bushing IEEE 693-2005 Qualification - PL
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2013 Life of a Transformer™ 56
Don’t Forget to Adequately Anchor Your Spares
Whittaker– NISEE / EERC
Halil– NISEE / EERC
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2013 Life of a Transformer™ 57
– National Information Service for Earthquake Engineering, EERC, University of California, Berkeley
– Fierro, E. January 19 2010 Photo Gallery – Haiti 2010. Pacific Earthquake Engineering Research Center
– Institute of Electrical and Electronic Engineers (IEEE). “IEEE 693-2005, IEEE Recommended Practice for
Seismic Design of Substations”, The Institute of Electrical and Electronic Engineers, Inc. 3 Park Avenue, New
York, NY10016
– International Code Council (ICC). “2012 International Building Code”, International Code Council, Inc. 4051
West Flossmoor Road, Country Club Hills, IL, 60478
– California Building Standards Commission (CBSC). “2010 California Buldign Code of Regulations Title 24,
Part 2, Volume 1 of 2”, California Building Standards Commission, 2525 Natomas Park Drive, Suite 130
Sacramento, CA 95833
– American Society of Civil Engineers (ASCE). “ASCE/SEI 7-10, Minimum Design Loads for Buildings and
Other Structures”, The American Society of Civil Engineers, 1801 Alexander Bell Drive, Reston, Virginia
20191
– International Conference of Building Officials (ICBO). “1997 Uniform Building Code Volume 2”, International
Conference of Building Officials, 5360 Workman Mill Road, Whittier California, 90601
– Institute of Electrical and Electronic Engineers (IEEE). “IEEEC57.114-1990, IEEE Seismic Guide for Power
Transformers and Reactors”, The Institute of Electrical and Electronic Engineers, Inc. 345 East 47th Street,
New York, NY10017
References
© Doble Engineering Company
2013 Life of a Transformer™ Seminar
February 18-21, 2013
San Diego, California USA
Seismic Qualification
Requirements for Transformers
Travis Soppe, PE – W.E. Gundy & Associates Inc.
Mathew Brien – SPX Transformer Solutions, Inc. © Doble Engineering Company