Project Title/ID Number Analytical Models for Electrical Equipment Connected by Rigid Buses—Lifelines 401b
Start/End Dates 10/1/02—9/30/03
Project Leader Armen Der Kiureghian (UCB/Faculty)
Team Members Jerome Sackman (UCB/Faculty), Junho Song (UCB/Grad Student)
Project goals and objectives

This project extends previous work on analytical modeling of the interaction effect between electrical substation equipment connected by rigid buses. The goal is make refinements to interaction analysis by accounting for the prevailing uncertainties in the ground motion and equipment characteristics. Comparison with tests conducted by other PEER researchers are made.

Role of this project in supporting PEER’s vision

This project will produce analytical models and results for predicting the fragility of interconnected electrical substation equipment. These results are essential for predicting the reliability of the electrical substation system and the power network.

Methodology employed

Use is made of nonlinear random vibration analysis by the equivalent linearization method; the hysteretic behavior of the rigid bus is modeled by nonlinear differential equations fitted to finite element or test results. Reliability methods are used to account for uncertainty in equipment characteristics.

Brief description of past year’s accomplishments and more detail on expected Year 6 accomplishments

During the previous phase of this project, we designed a new rigid bus connector, which has improved characteristics in the sense that it reduces the adverse interaction effect. We also investigated the behavior of exiting designs of rigid buses as used in the industry.
During Year 6, we intend to develop models for predicting the fragility of the connected equipment items, accounting for the stochastic nature of the ground motion as well as the uncertainty in the system characteristics. Comparisons will also be made with ongoing tests being conducted at UC San Diego by other PEER researchers.

Other similar work being conducted within and outside PEER and how this project differs

Experimental phase of this project is being conducted at UC San Diego. We are also aware of work on electrical substation equipment connected by flexible buses being conducted in Canada. We are in close touch with these researchers and collaborate in many ways. We are also aware of related work at the New Jersey Institute of Technology. So far, we have exchanged publications and held some useful discussions.

Plans for Year 7 if this project is expected to be continued

We hope to be able to go to the next step, which will be the reliability analysis of the electrical substation as a system. We are currently doing some preliminary work in this area.

Describe any instances where you are aware that your results have been used in industry

We designed a new rigid bus connector, which has been shown to have vastly improved characteristics. The PG&E has commissioned two prototypes of this design, which are now being tested at UC San Diego. We hope that this design will be used by the industry in the near future.

Expected milestones

Final report to be completed by August 30, 2003.


Final report, including details of all analytical models and methods and correlations with tests results.