Electric transmission lines suffer from many hazards, including wind-induced vibrations (WIV), which can lead to fatigue failure of the transmission conductors. Current vibration mitigation methods do not adequately address WIV because they overwhelmingly rely on narrow-band fixed absorbers. A mobile damping robot (MDR) can overcome the limitations of these fixed absorbers by actively transporting them to locations of highest amplitude on the cable; i.e., antinodes. These antinodes are where the absorbers can most efficiently remove energy from the system. While analyses have been performed for vibration absorbers on transmission line conductors, they have not been in the context of a mobile damping robot (MDR). There is a need to investigate the potential impact of the MDR on a transmission line and the resulting implications for the MDR's development. In this thesis, we explore the dynamics of a power line conductor through finite element analysis (FEA) and modal testing. We perform numerical analysis in MATLAB using equations of motion obtained via Hamilton's Principle. We discuss the design and validation of an appropriate test bench and MDR prototype. We also experimentally investigate the ability of the MDR prototype to transport a mass along a conductor to antinode locations. Experimental results indicate that the damping robot is indeed able to navigate to cable locations of highest amplitude corresponding to antinodes. We then conclude and discuss future work. The insights gained from this research lay a foundation to guide further development of the MDR. Through this work, we are better able to define the operating conditions of the MDR, which will facilitate the creation of a more robust, adaptable control framework for expanded capability. / Master of Science / Power transmission lines are important civil structures used to deliver electricity across the nation. However, these lines are subject to an array of hazards that can damage them. One such hazard is vibration due to wind, which can cause fatigue damage, leading to power line failure and outages. A popular form of vibration control is the use of a fixed vibration absorber, which has significant limitations. A mobile damping robot (MDR) can greatly improve upon the efficiency of these absorbers by transporting them to optimal locations along the power line. This thesis explores the utility and feasibility of an MDR to do so. We investigate with the help of engineering software and establish the conditions for experimentation. Our research suggests that the MDR prototype we constructed can autonomously navigate itself along the power line to optimal locations. This research will guide improvements to the MDR so that it can be more effective under real-world conditions.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/115632 |
| Date | 03 July 2023 |
| Creators | Choi, Andrew C. |
| Contributors | Mechanical Engineering, Barry, Oumar, Shahab, Shima, Zuo, Lei |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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