Department of Electrical and Electronic Engineering

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    Analysis and Quantification of Position Sensor Offset Error in Feedforward Controlled PMSMs
    (Institute of Electrical and Electronics Engineers, 2022-10-13) Edirisinghe, E. A. Y. G; Rajapaksha, L.T.W; Abeyratne, S. G; Kuruppu, S. S
    Permanent Magnet Synchronous Machines (PMSM) are popular in transportation electrification applications due to their inherent torque density and ease of control. In torque control applications, field-oriented control (FOC) ensures optimal torque production. However, PMSMs require a rotor position information for FOC, achieved with sensors such as encoder, resolver or linear hall sensor. Feedforward controlled FOC being one key form of PMSM control, the position sensor signal accuracy is paramount. Due to the harsh environments experience by systems in the transportation segment, the position sensor has the potential to misalign from the initially calibrated alignment. This paper focuses on the effects of such position sensor misalignment on feedforward-controlled drives. A novel quantification strategy to detect the failure mode has been presented with analytical details. The methodology is verified through simulation and validated by experimental results. Moreover, a brief analysis-contrasting the effects of position sensor misalignment on feedback and feedforward-controlled drives are presented.
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    An Incentivized and Optimized Dynamic Mechanism for Demand Response for Managing Voltage in Distribution Networks
    (IEEE, 2022-09-05) Rahman, M. M; Arefi, A; Shafiullah, G. M; Hettiwatte, S; Azizivahed, A; Muyeen, S. M
    The voltage regulation in distribution networks is one of the major obstacles when increasing the penetration of distributed generators (DGs) such as solar photovoltaics (PV), especially during cloud transients, causing potential stress on network voltage regulations. Residential demand response (DR) is one of the cost-effective solutions for voltage management in distribution networks. However, the main barriers of DR implementation are the complexities of controlling a large number and different types of residential loads, satisfying customers’ preferences and providing them fair incentives while identifying the optimum DR implementation locations and sizing as well as cooperating with the existing network equipment for the effective voltage management in the networks. A holistic and practical approach of DR implementation is missing in the literature. This study proposes a dynamic fair incentive mechanism using a multi-scheme load control algorithm for a large number of DR participants coordinating with the existing network equipment for managing voltage at medium voltage (MV) networks. The multi-scheme load control is comprised of short-interval (10-minute) and long-interval (2-hour) DR schemes. The dynamic incentive rates are optimized based on the energy contribution of DR participating consumers, their influence on the network voltage and total power loss improvement. The proposed method minimizes the DR implementation cost and size, fairly incentivizes the consumers participating in the DR and priorities their consumption preferences while reduces the network power losses and DGs’ reactive power contributions to effectively manage the voltage in the MV networks. An improved hybrid particle swarm optimization algorithm (IHPSO) is proposed for the load controller to provide fast convergence and robust optimization results. The proposed approach is comprehensively tested using the IEEE 33-bus and IEEE 69-bus networks with several scenarios considering a large number of DR participants coordinated with the DGs and on-load tap changer (OLTC) in the networks.
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    Wireless Power Transfer for Cardiac Pacemaker
    (IEEE Computer Society, 2022-08-17) Uthayakumar, U; Jayaweera, Y
    Cardiac pacemaker is an electronic device used to regulate the heartbeat of patients suffering with congenital heart defects. Considering the limitations in lifespan of current cardiac pacemaker battery, a wireless charging mechanism for cardiac pacemaker is proposed in this paper. Circuitry model and electromagnetic geometry is developed using Ansys Maxwell and Ansys High-Frequency Structure Simulator (HFSS) software to analyze three main technical issues such as: implantation, efficiency and safety. Specific Absorption Rate (SAR) and induced electric field in a 3-D model human body is evaluated by numerical analysis and simulation to ensure that the developed system adheres to safety limits proposed by Institute of Electrical and Electronics Engineers (IEEE) standard and International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines.