PhD defence by Muhammad Umair Mutarraf


08.09.2022 kl. 13.00 - 16.00


Muhammad Umair Mutarraf, AAU Energy, will defend the thesis "Coordinated Control and Management of Multiple Electric Ships forming Seaport Microgrids"


Coordinated Control and Management of Multiple Electric Ships forming Seaport Microgrids


Muhammad Umair Mutarraf


Professor Josep M. Guerrero


Professor  Juan C. Vasquez
Assistant Professor Yajuan Guan


Associate Professor Zhenyu Yang, Aalborg University, Denmark (Chairman)
Associate Professor Nursyarizal Mohd Nor, Universiti Teknologi PETRONAS
Associate Professor Muzamir Isa, Universiti Malaysia Perlis


Besides environmental issues, the main technical challenge in conventional Shipboard Microgrids (SMGs) are the long-term
and short-term power fluctuations caused by the dynamic loads and environmental changes in the sea exacerbate onboard
generators wear and tear. Among other challenges, the operational and maintenance cost for such ships is higher. The
integration of energy storage system (ESS) is found out to be an alternative solution but their sole integration with several
types of ships is challenging especially longer route ships due to cost, lifecycle, energy, and power density concerns.
Therefore, the use of a single ESS device may result in an increase in weight, cost, size, which leads to the hybridization of
two or more ESS devices as a single ESS device either can provide high energy or high-power density benefits only.
Therefore, the potential ESS device and its hybrid combination need to be analyzed. Further, ESS in the maritime sector is
relatively new, hence, different benefits that can be achieved using them on board along with different architectures need
to be explored.
The first part of this thesis, therefore, highlights these concerns by reviewing the architecture of different types of SMGs,
several types of ESS devices, and optimal selection based on comparative analysis and their benefits that can be achieved in
the maritime sector. In SMGs, synchronous generators onboard operate under varying load profiles due to the
environmental changes in the sea resulting in low loading and high loading operation, which results in declining the
efficiency of an engine. To tackle this problem, a droop-based adaptive power management system for hybrid SMG is
proposed to achieve quasi load-leveling, a trade-off between utilization of battery and operating diesel generators at their
optimal point, where during low-loading and high loading conditions, ESS is utilized to absorb and supply power
respectively. Further, renewable energy sources (RES) and battery-equipped ships could be used to support seaport, grid,
etc., particularly beneficial for smaller islands with limited sources of energy referred to as Ship-to-X or Ship-to-grid (S2G).
The last part addresses the benefit of ESS in SMGs that can be achieved by its use for cold-ironing purposes. One of the
major effects of the maritime sector is the emission of ships at ports, as when fossil fuel-powered ships arrive at ports their
auxiliary engines are turned on to power the auxiliary loads. One solution to reduce emissions at some major ports is
addressed by powering ships through a shore connection, which is connected to the national grid also referred to as cold-
ironing. The major obstacle in using such an approach is the lack of availability of cold-ironing facilities at most of the ports.
Alternatively, we propose multiple electric ship-based seaport microgrid to provide a mobile cold-ironing facility to power
auxiliary loads of fossil fuel-powered ships during their port stays. This sort of strategy will minimize emissions from ports
and is particularly useful for ports that are far from the national grid such as remote islands. To share power among various
SMGs autonomously, an adaptive multi-mode decentralized control based on V-I and I-V droop control is proposed for
proportional power-sharing among different SMGs.



THE DEFENCE will be IN ENGLISH - all are welcome.




AAU Energy


Pontoppidanstræde 105 room 4.127


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