The Faculty of Engineering is located at the University's main campus and offers tuition and supervision to about 477 students at both undergraduate and postgraduate levels while conducting research in all fields covered by its departments. https://www.um.edu.mt/library/oar/handle/123456789/519 2026-10-24T16:29:16Z 2026-10-24T16:29:16Z Mikhaylov, Yury Buticchi, Giampaolo https://www.um.edu.mt/library/oar/handle/123456789/150368 2026-10-23T05:43:23Z 2023-01-01T00:00:00Z

Title: A gate driver for parallel connected MOSFETs with crosstalk suppression Authors: Mikhaylov, Yury; Buticchi, Giampaolo Abstract: New semiconductor materials offer several advantages for modern power systems, including low switching and conduction losses, excellent thermal conduction of a die, and high operation temperature. Avionics is one of the main beneficiaries of the progress in power devices, as it enables more compact and lighter converters for future More Electrical Aircraft. However, these advancements also come with new challenges that must be addressed to avoid potentially dangerous situations and fully utilize the capabilities of fast SiC MOSFETs. One such challenge is the high drain voltage rate during the switching process, which leads to a significant injection of current into the gate circuit (crosstalk effect). This increased current injection increases the risk of shoot-through conduction and thermal runaway. Although preventive measures are well-known, they offer limited protection in the case of parallel MOSFET connections. Therefore, this paper considers crosstalk features for parallel MOSFET connections, such as parasitic inductance of gate driver trace and gate voltage distribution. A special model is proposed to predict the magnitude of induced gate voltage under different conditions considering the nonlinear behavior of the MOSFET reverse capacitance. A new clamp circuit with an individual low-inductance path for each parallel switch is also proposed to suppress the consequences of crosstalk. The modified circuit operates independently from the main gate driver circuit; therefore, it does not change the switching time and electromagnetic interference pattern of the inverter. The efficiency of the new gate driver is confirmed through simulation and experimental results.

2023-01-01T00:00:00Z Jing, Fengmei Guo, Jiahao Wang, Xinru Mei, Yunlei Zhang, Dingming Ye, Weixiang Le, Conghuan Fan, Yali Zhu, Yanqi Micallef, Christopher Sant, Tonio Mollicone, Jean-Paul https://www.um.edu.mt/library/oar/handle/123456789/150319 2026-10-22T06:14:45Z 2026-01-01T00:00:00Z

Title: Towing response and drag reduction in a semi-submersible floating offshore wind turbine platform with fairings Authors: Jing, Fengmei; Guo, Jiahao; Wang, Xinru; Mei, Yunlei; Zhang, Dingming; Ye, Weixiang; Le, Conghuan; Fan, Yali; Zhu, Yanqi; Micallef, Christopher; Sant, Tonio; Mollicone, Jean-Paul Abstract: To reduce the wet-towing resistance of a semi-submersible floating offshore wind turbine (FOWT) platform, this study proposes the installation of fairings on the outer columns and investigates their influence on the platform motion response during towing through numerical simulation. The drag reduction performance of a single fairing on a cylindrical column is experimentally validated through scaled towing tank tests. Four fairing arrangement schemes are then designed, from which two schemes that satisfy intact stability requirements are selected. A platform-level CFD analysis is further conducted to quantify the drag reduction in the full platform, showing that Scheme 1 (all forward) and Scheme 2 (two forward, one aft) achieve drag reductions of 5.09% and 5.95%, respectively. A numerical representation of the complete towing system, comprising the platform, tugboat, and cables, is developed within the AQWA environment. The hydrodynamic model of the unmodified platform is numerically validated against free-decay data. The study proceeds with a frequency-domain assessment of the platform’s hydrodynamic behavior, followed by time-domain simulations to evaluate its motion responses under regular wave excitation. The results show that the triangular fairing provides stable drag reduction under different towing speeds and draft conditions. The fairings predominantly alter the added mass, radiation damping, and RAO in the pitch direction, while their influence on the heave and roll motions is relatively limited. For Scheme 1, the peak pitch added mass increases by 36.7%, the peak pitch radiation damping increases by 223.8%, and the peak pitch RAO increases by 20.3% relative to the bare platform. Scheme 2 induces smaller overall perturbations to the motion response compared with Scheme 1, while also offering a slightly higher drag reduction at the platform level. The study reveals that while fairings effectively reduce towing resistance, they also significantly modify the pitch motion characteristics of the platform. In engineering applications, both drag reduction benefits and motion performance changes should be comprehensively considered, and the fairing arrangement should be selected accordingly.

2026-01-01T00:00:00Z Patil, Sangita Jadhav, Seema Tran, Tien Anh Bhowmik, A. Panda, Jibitesh Kumar https://www.um.edu.mt/library/oar/handle/123456789/149849 2026-10-08T07:40:57Z 2026-01-01T00:00:00Z

Title: Smart and sustainable energy management of hybrid PV/wind systems using AI-based fuzzy control Authors: Patil, Sangita; Jadhav, Seema; Tran, Tien Anh; Bhowmik, A.; Panda, Jibitesh Kumar Abstract: The rapid growth of renewable energy penetration has intensified the need for robust and intelligent energy management strategies capable of addressing the intermittency of solar and wind resources. This study presents a simplified fuzzy logic controller (FLC)–based energy management system (EMS) for a grid-connected PV/Wind hybrid system integrated with battery energy storage. A fuzzy logic–based Maximum Power Point Tracking (MPPT) scheme is developed for the photovoltaic subsystem to ensure efficient power extraction under variable irradiance and temperature conditions. MATLAB/Simulink-based investigations reveal that the proposed FLC-MPPT achieves a tracking efficiency of 98.6%, with a settling time reduced by 32% compared to conventional perturb-and-observe methods. The hybrid EMS effectively coordinates power flow among PV, wind, battery, and grid, reducing grid dependency by 41% and improving battery state-of-charge regulation within ±5% limits under dynamic load conditions. Battery cycling stress is reduced by 27%, enhancing storage lifespan. Furthermore, the integration of a Unified Power Flow Controller (UPFC) significantly improves system resilience under grid disturbances, achieving 38% voltage sag mitigation and 45% reduction in power oscillations during simulated fault conditions. The results confirm that the proposed simplified FLC-based EMS enhances energy utilization, system stability, and power quality in grid-linked hybrid renewable systems. This work directly supports UN SDG 7 (Affordable and Clean Energy) and SDG 13 (Climate Action) by enabling efficient, reliable integration of renewable energy sources into smart power systems.

2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/149749 2026-10-06T13:29:44Z 2025-01-01T00:00:00Z

Title: Human-cobot assembly station for low volume production runs : a cost-effective approach through modularity and scalability Abstract: In today’s increasingly volatile manufacturing environment, companies are under pressure to produce highly customised products in smaller volumes without compromising efficiency, quality, or cost. Traditional dedicated assembly lines (DMS), designed for high-volume production, lack the flexibility needed to adapt to these emerging demands. This research investigates and proposes a solution through the development of a Reconfigurable Human-Cobot Assembly System (RHCAS). This modular, scalable approach combines the strengths of Reconfigurable Assembly Systems (RAS) with Human-Robot Collaboration (HRC) under the guiding principles of Industry 5.0. This thesis outlines the design and evaluation of a generic RHCAS architecture designed to support low-to-medium volume production with high product variety. A comprehensive literature review identifies key design principles from existing HumanCobot Assembly Systems (HCAS), RAS and RHCAS. A modified Modular Function Deployment (MFD) framework is proposed to generate a generic physical RHCAS architecture. The developed architecture is then applied and validated through a case study. Stakeholder evaluations from both industrial and academic backgrounds provided qualitative insights into the practicality of the proposed architecture, while quantitative financial and productivity analyses confirmed its potential feasibility. The results validate the central hypothesis that a well-structured, modular RHCAS can provide manufacturers with a cost-effective and adaptable alternative to traditional assembly systems, particularly in low-volume, high-mix production environments. This research contributes a novel RHCAS design methodology based upon the principles of Integrated Product Development (IPD), promoting concurrent and modular design thinking. Description: M.Sc. IPD(Melit.)

2025-01-01T00:00:00Z