Havard Engineering Inc. Web Page Havard Engineering Inc. controlling vibration and galloping for the electric power supply industry

Havard Engineering Inc.

    Principals

David G. Havard, Ph.D., P.Eng.
Jana Havard, M.A.Sc., P.Eng.

E-mail: dhavard@rogers.com

NEW 2012 WORKSHOPS

  • Overhead Power Line Asset Management - Assessment, Upgrading and Life Extension.

  • Presented by Dr. David Havard and Dr. Samy Krishnasamy

  • Update of workshops given between 1995 and 2011

  • Presented in Brazil, Canada, Denmark, England, France, Ireland, Japan, Malaysia, Netherlands, Norway, Russia, South Africa, Spain and USA.

  • Workshop Schedule:

    Toronto.......................April 16 and 17, 2012
    Montreal or Halifax...........October 15 and 16, 2012

    • press here for a full description of the courses:

    Services Offered

    Based on over 40 years experience with electrical power utilities across the globe, Havard Engineering Inc. provides mechanical and civil engineering services to users of overhead electric power lines.

    To speed up loading this web page we have reduced the size of our photographs on the information pages. Also we have created two albums if you wish to see or download the full size images. You can reach these by clicking on the thumbnails. More detailed information is available on each topic by clicking on the heading.

    Single Conductor Vibration

    These services include diagnosis and control of problems due to aeolian vibration of single conductors which may become apparent through fatigue or wear of conductors, suspension clamps, Stockbridge vibration dampers and even tower members. A live line vibration recorder in use on an operating line to monitor conductor motions at an AGS clamp is shown on the right.

    Bundle Conductor Vibration and Oscillation

    Bundle conductors are susceptible to both aeolian vibration and wake induced oscillation. When two, three, four or more subconductors are used vortex wakes from the leading subconductors impact downstream subconductors and cause complex oscillation modes involving all subconductors in the bundle. A typical spacer-damper used to control both of these wind-induced vibratory motions is shown on the left.

    Conductor Galloping

    Galloping of conductors due to icing and wind action can be significantly reduced by the addition of detuning pendulums designed specifically for the line section by Havard Engineering Inc., and manufactured by associated companies. Interphase spacers and detuning pendulums installed on a two-conductor bundle line for galloping control are shown on the right.

    Structural Testing

    The application may require monitoring the vibration on the conductors or towers and/or mechanical testing of worn or aged components. A tensile test of a strand of an aged ACSR conductor is shown on the left.

    Analysis of Special Problems

    Analytical methods are used to evaluate alternative designs for special needs and arrangements. Computer programs have been written and applied to simulate critical features of transmission line behaviour, such as determining the limits of stability of hinged horizontal vee insulated arm designs under high winds.

    An analytically determined plot of the clearance ellipses for galloping on a span of a two circuit transmission line is shown on the immediate right using the traditional method. The clearance envelopes calculated using the new criterion based on analysis of films of galloping motions is shown on the far right.

    Workshops and Courses

    Open courses on overhead line vibration and assessment of aged lines have been given in numerous locations in Asia, Europe, and North and South America.

    In-House Courses

    Additionally, in-house courses have been tailored to specific utility needs and presented to technical staff at their workplace.

    The topics covered include:

  • Assessment, of conductors, line components, hardware and structures
  • Upgrading and refurbishment of lines, foundations and structures
  • Conductor vibration, wake induced oscillation and galloping - measurement and control
  • Mechanical aspects of all types of fibre optic cables
  • Impact of the 1998 Canadian ice storm on overhead lines
  • Damage to structures due to wind induced vibration

    • Technical Contributions

  • Active Member and Past Convenor: CIGRE SC22 WG11 "Mechanical Aspects of Overhead Conductors".
  • Senior Life Member of IEEE, Towers, Poles and Conductors Subcommittee.
  • Active Member of IEEE Working Group on Conductors
  • Past Adjunct Professor, Mechanical Engineering Dep't, University of Toronto.
  • Technical Coordinator of CEA Interest Group on Transmission Line Asset Management (1999-2000)
  • Author of over 200 papers and presentations on mechanical problems on overhead power lines.

    • Technical Papers and Presentations

    To contact us please send an e-mail to: dhavard@rogers.com

    Updated January 13, 2012