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Transient suppression in hybrid electric ship power systems

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posted on 2023-05-28, 09:21 authored by Shagar, V
The requirements for power quality in ship power systems have been increasing over the years. This is an essential consequence of improving the efficiency of the onboard power network and reduce emissions in the long term. The connection of sophisticated navigation and measuring instruments into the grid has also necessitated a higher quality of power to ensure optimal operating conditions for all the loads and avoid malfunction of equipment onboard a ship. The most significant challenge to maintain power quality for the shipboard power system is to mitigate the transient conditions that arise due to the widely varying load conditions imposed by varying sea conditions as well as fluctuating onboard power demands. This work has attempted to illustrate the extent of the transient phenomena due to load changes in the case of vessels with hybrid mechanical and electrical propulsion. Subsequently, control solutions to limit and reduce such transient conditions and their propagation that include energy storage devices such as the capacitor and battery have been developed. A shipboard power system with hybrid propulsion has been modeled and the transient responses to various types of load changes during the course of different modes of operation possible for the hybrid system have been analyzed. An active damping strategy has been developed to reduce the torsional vibrations at the drive shaft of the thruster due to extreme load conditions while avoiding overdesign of the shaft itself. The strategy has been extended further to incorporate a capacitor clamped inverter to reduce the electrical transients that are caused by propagation of these transients from the mechanical portion of the hybrid propulsion system into the electrical system. A Model Predictive Control (MPC) strategy has also been developed for a Battery Energy Storage System (BESS) to mitigate the electrical transients arising as a result of propulsion and service load transients while keeping the main engine in the optimum operating range. The MPC power converter control allows for the battery to smoothen the electrical frequency profile during different types of extreme load change conditions and allows for charging and discharging the battery repeatedly. The findings of this research work have significant implications in defining the extent of transient conditions in hybrid power systems. In addition, the efficacy of integrating an energy storage system into the hybrid electric propulsion power network in order to reduce the transients has also been proven.

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Copyright 2019 the author Chapter 2 appears to be the equivalent of a post-print version of an article published as: Shagar, V., Jayasinghe, S. G., Enshaei, H., 2017. Effect of load changes on hybrid shipboard power systems and energy storage as a potential solution: A review, Inventions, 2(3) 1-22. Copyright 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Chapter 3 appears to be the equivalent of a pre-print version of an article published as: Shagar, V., Gamini, S., Enshaei, H., 2017. Effect of load changes on hybrid electric ship power systems, 2016, IEEE 2nd Annual Southern Power Electronics Conference (SPEC), Auckland, 2016, pp. 1-5. Copyright 2017 IEEE. Reprinted, with permission. In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of University of Tasmania's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink. --https://journals.ieeeauthorcenter.ieee.org/choose-a-publishing-agreement/avoid-infringement-upon-ieee-copyright/ Chapter 4A appears to be the equivalent of a post-print version of an article published as: Jayasinghe, S. G., Shagar, V., Enshaei, H., Mohammadi, D., Vilathgamuwa, M., 2016. Capacitor-clamped inverter based transient suppression method for azimuth thruster drives, 2016 IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, 2016, pp. 2813-2820. Copyright 2016 IEEE. Reprinted, with permission. In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of University of Tasmania's products or services. Internal or personal use of this material is permitted. If interested in reprinting/republishing IEEE copyrighted material for advertising or promotional purposes or for creating new collective works for resale or redistribution, please go to http://www.ieee.org/publications_standards/publications/rights/rights_link.html to learn how to obtain a License from RightsLink. --https://journals.ieeeauthorcenter.ieee.org/choose-a-publishing-agreement/avoid-infringement-upon-ieee-copyright/ Chapter 4B appears to be the equivalent of a post-print version of an article published as: Shagar, V., Gamini, S., Enshaei, H., 2016. A capacitor-clamped inverter based torsional oscillation damping method for electromechanical drivetrains, in MATEC Web of Conferences, Volume 45, 2016. Copyright Owned by the authors, published by EDP Sciences, 2016. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, (https://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Chapter 5 appears to be the equivalent of a post-print version of an article published as: Shagar, V., Jayasinghe, S. G., Enshaei, H., 2018. Frequency transient suppression in hybrid electric ship power systems: A model predictive control strategy for converter control with energy storage, Inventions, 3(1) 1-15. Copyright 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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