Amirmehdi Yazdani

This paper presents a distributed mission planning system that enables a team of autonomous underwater vehicles (AUVs) for effective underwater chlorophyll sampling. The proposed system is developed based on a distributed algorithm that optimizes the real-time task allocation and mission planning of AUVs in a cooperative fashion while considering environmental and vehicular constraints to ensure efficient and coordinated sampling efforts. A realistic case study of a chlorophyll sampling mission in Australia's Great Barrier is utilized to investigate the performance of the proposed system in a restricted mission time and in the exposure to the uncertainty of the mission. Simulation studies confirm the effectiveness and resilience of the proposed system and showcase its potential as a valuable tool for advancing underwater chlorophyll sampling missions.

In this paper, a comprehensive review of microgrids frequency control by using the Virtual Inertia (VI) is presented. Due to the widespread penetration of renewable energy sources (RESs) and distributed generators (DGs), a new system stability issue has been recently emerged. This issue is associated with the reduction and variation of inertia in the microgrid that is triggered by the utilization of power electronics interfaces to connect the RESs and DGs into the system. This leads to a higher system uncertainty requiring more complex system operation and control. To maintain microgrid reliability and to provide efficient use of RESs and DGs, the synthesis and control of virtual inertia should be a key technology to achieve a flexible operation in current and future microgrids. This paper provides a comprehensive survey on the fundamental aspects of synthesis and control of the virtual inertia for microgrid control. More specifically, an overview of the low inertia issue in microgrids with a high share of RESs and the role of virtual inertia are highlighted. Moreover, this paper reviews the role of battery energy storage system (BESS), as one of the novel VI emulated techniques, in enhancing system inertia.

Due to inevitable prospect of failure in power electronics, the demand for reliability improvement in adjustable speed drives become important, particularly for the induction motor drives being widely used in the industry. In this study, a mathematical approach is introduced to elucidate the relation between the controller output and applied voltage to the motor terminal, the place in which the fault might occur. The relation is derived based on the comparison of healthy and postfault operation of induction motor drives controlled in a field-oriented control (FOC) manner. Without any modification to the overall closed-loop controller structure, the fault is perceived as a disturbance to the system. Based on this approach, the lumped impact of the open-circuit fault (OCF) and topology reconfiguration is identified and compensated by injecting a suitable feedforward term. The effectiveness of the proposed fault-tolerant controller is verified and compared through the simulation and experiment, ensuring the smooth operation in postfault mode.