@article{rachi_cen_bipu_khan_husain_2021, title={Design and Development of a Multi-Port Converter for Marine Microgrid Applications}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE47101.2021.9595808}, abstractNote={In this work, a multi-port converter (MPC) design is presented that works as the key building block of a marine microgrid. An emulated wave energy converter (WEC) serves as the renewable energy resource of this microgrid system. The proposed MPC is comprised of a WEC interfacing port, energy storage port, and a split-phase AC load/grid port. Stable power exchange among these dissimilar energy resources are facilitated through a 400V internal DC bus. The full MPC design along with its control and thermal model is developed and implemented in PLECS. Commercially available SiC power modules have been used to leverage its high switching frequency capability that to achieve compact system design with reduced passive component sizes. Individual controller for each energy resource interfacing converter is analyzed, developed and implemented initially. A state-machine is developed utilizing these discrete controllers for MPC operation where all three ports are active simultaneously. These discretized controllers along with voltage/current sensor models with limited bandwidth and response delay in the feedback path are implemented in PLECS to emulate practical controller deployment. Simulation results are provided to validate both the power stage and the discrete controller design. Furthermore, iterative thermal analysis is carried out to have a realistic estimation of the device junction temperature during rated condition to evaluate the efficacy of the thermal management system. Finally, a virtual prototype design of the MPC is presented.}, journal={2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Rachi, Md Rifat Kaisar and Cen, Siye and Bipu, Md Rashed Hassan and Khan, Mehnaz Akhter and Husain, Iqbal}, year={2021}, pages={1184–1190} }
 @article{rachi_khan_husain_2021, title={Local Measurement-Based Protection Coordination System for a Standalone DC Microgrid}, volume={57}, ISSN={["1939-9367"]}, DOI={10.1109/TIA.2021.3091945}, abstractNote={A reliable protection coordination system between the power electronic converters and solid-state device-based fast protection unit in a standalone dc microgrid supplied by a wave energy converter (WEC) and an energy storage unit is presented. A system model with solid-state circuit breakers is developed in Piecewise Linear Electrical Circuit Simulation (PLECS) to analyze the steady-state operation as well as faulted conditions. The effect of both resistive and constant power loads on a current-limited bus controlling converter behavior during an overload event is analyzed theoretically. Also, the variation in the WEC power output and its effect on bus voltage during overload are investigated. The analysis has led to a novel dual current–voltage feedback-based protection coordination system. The method does not require any communication between the solid-state circuit breakers and converters and eliminates the need for adaptive updating of the overcurrent threshold with varying renewable generation output. Bus capacitor discharge during a short-circuit is analyzed theoretically as well to formulate an instantaneous trip threshold selection utilizing device gate driver functionality. The proposed protection coordination system ensures rapid fault isolation and continued power delivery to the healthy segments. An SiC-based bidirectional, solid-state dc circuit breaker prototype is designed and fabricated, which has been used to implement the proposed protection method with a 380-V dc bus-based system.}, number={5}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Rachi, Md Rifat Kaisar and Khan, Mehnaz Akhter and Husain, Iqbal}, year={2021}, month={Sep}, pages={5332–5344} }
 @article{bipu_awal_cen_zabin_khan_lubkeman_husain_2021, title={Secondary Voltage and Frequency Regulation for Grid Re-Synchronization in Microgrid with Unified Virtual Oscillator Controlled Multi-port Converters}, ISSN={["2329-3721"]}, DOI={10.1109/ECCE47101.2021.9595901}, abstractNote={Unified Virtual Oscillator Controller (uVOC) is a type of oscillator based nonlinear time domain controller that achieves faster primary control response than conventional droop control as no phase-locked loop (PLL) is required. uVOC can be used effectively for either grid following or grid-forming voltage source converters. Grid-forming converter is essential for a microgrid to operate in islanded mode in addition to the more common grid-connected mode. In this paper, a secondary regulation scheme is proposed to augment the capability of uVOC based on a Multi-port Converter (MPC) by adding voltage and frequency regulation for grid re-synchronization. With this method, changing primary controller is not required and seamless transition is achieved. To implement this secondary regulation, communication or data exchange between different components is required. The network connectivity is implemented based on the RIAPS platform, an open-source distributed operating system developed for real-time control of microgrid/smartgrid systems. Finally, the suitability of proposed secondary regulation with uVOC based MPC was verified through simulation and experiment on a microgrid testbed.}, journal={2021 IEEE ENERGY CONVERSION CONGRESS AND EXPOSITION (ECCE)}, author={Bipu, Md Rashed Hassan and Awal, M. A. and Cen, Siye and Zabin, Salina and Khan, Mehnaz and Lubkeman, David and Husain, Iqbal}, year={2021}, pages={900–905} }
 @article{khan_ahmed_husain_sozer_badawy_2015, title={Performance Analysis of Bidirectional DC-DC Converters for Electric Vehicles}, volume={51}, ISSN={["1939-9367"]}, DOI={10.1109/tia.2015.2388862}, abstractNote={This paper presents the performance analysis and comparison of two types of bidirectional dc-dc converters-cascaded buck-boost capacitor in the middle and cascaded buck-boost inductor in the middle for use in plug-in electric and hybrid electric vehicles. The comparison of the two converters is based on device requirements, rating of switches and components, control strategy, and performance. Each of the converter topologies has some advantages over the other in certain aspects. Efficiency analysis has been carried out for specific scenarios in vehicle applications. The simulation and experimental results are provided for both converter types.}, number={4}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Khan, Mehnaz Akhter and Ahmed, Adeeb and Husain, Iqbal and Sozer, Yilmaz and Badawy, Mohamed}, year={2015}, pages={3442–3452} }
 @article{khan_husain_islam_klass_2014, title={Design of Experiments to Address Manufacturing Tolerances and Process Variations Influencing Cogging Torque and Back EMF in the Mass Production of the Permanent-Magnet Synchronous Motors}, volume={50}, ISSN={["1939-9367"]}, DOI={10.1109/tia.2013.2271473}, abstractNote={A number of manufacturing challenges exist in creating a robust permanent magnet synchronous motor (PMSM) design to meet critical requirements for cogging torque and torque ripple in specific applications. In addition, reduction of back EMF harmonics that lead to torque ripple is also required during design. Due to manufacturing tolerances, maintaining capability with these requirements is very difficult especially for mass production of units. A design of experiments (DOE) that combines manufacturing tolerances with assembly process variations is proposed here to address the sensitivity of cogging torque and harmonics. The limits for the parts and the process variations are extracted from an actual production environment. The DOE is laid out according to one of the robust engineering matrices chosen from Taguchi's method. The findings of the DOE are then utilized to set the tolerance limits for manufacturing the rotor magnets and to set the allowance for the rotor assembly process variation. The method helps limit the cogging torque and harmonics within predefined bands and make the motor design robust. This paper also investigates the capability of maintaining the tolerances of magnets for a surface mounted PMSM. The analysis is done using finite-element method and verified with experimental results.}, number={1}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Khan, Mehnaz Akhter and Husain, Iqbal and Islam, Mohammed Rakib and Klass, Jeffrey T.}, year={2014}, pages={346–355} }
 @article{khan_husain_sozer_2013, title={Integrated Electric Motor Drive and Power Electronics for Bidirectional Power Flow Between the Electric Vehicle and DC or AC Grid}, volume={28}, ISSN={["1941-0107"]}, DOI={10.1109/tpel.2013.2258471}, abstractNote={This paper presents an integrated traction machine and converter topology that has bidirectional power flow capability between an electric vehicle and the DC or AC supply or grid. The inductances of the traction motor windings are used for bi-directional converter operation to transfer power eliminating the need for extra inductors for the charger and vehicle-to-grid (V2G) converter operation. The electric powertrain system size and weight can be minimized with this approach. The concept has been analyzed with finite element coupled simulation with dynamic analysis software. Experimental results are also provided with an electric machine. The interleaving technique has been used with the inductors to share the current and reduce the converter switching stresses. The proposed integrated converter can operate in the traction mode and in the bidirectional power flow mode when energy can be transferred between the vehicle and the DC or single phase AC supply.}, number={12}, journal={IEEE TRANSACTIONS ON POWER ELECTRONICS}, author={Khan, Mehnaz Akhter and Husain, Iqbal and Sozer, Yilmaz}, year={2013}, month={Dec}, pages={5774–5783} }
 @inproceedings{khan_husain_islam_klass_2012, title={Design of experiments to address manufacturing tolerances and process variation influencing cogging torque and back EMF in the mass production of the permanent magnet synchronous motors}, DOI={10.1109/ecce.2012.6342359}, abstractNote={A number of manufacturing challenges exist in creating a robust permanent-magnet synchronous motor (PMSM) design to meet critical requirements for cogging torque and torque ripple in specific applications. In addition, reduction of the back electromotive force (BEMF) harmonics that lead to torque ripple is also required during design. Due to manufacturing tolerances, maintaining capability with these requirements is very difficult, particularly for mass production of units. A design of experiments (DOE) that combines manufacturing tolerances with assembly process variations is proposed here to address the sensitivity of cogging torque and harmonics. The limits for the parts and the process variations are extracted from an actual production environment. The DOE is laid out according to one of the robust engineering matrices chosen from Taguchi's method. The DOE results are then utilized to set the tolerance limits for manufacturing the rotor magnets and to set the allowance for the rotor assembly process variations. The method helps to limit the cogging torque and harmonics within predefined bands, thereby producing a robust motor. This paper also investigates the capability of maintaining the tolerances of magnets for a surface-mounted PMSM. The analysis is done using a finite-element method and verified with experimental results.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Khan, M. A. and Husain, I. and Islam, R. and Klass, J.}, year={2012}, pages={3032–3039} }
 @inproceedings{khan_husain_sozer_2012, title={Integrated electric motor drive and power electronics for bidirectional power flow between electric vehicle and DC or AC grid}, DOI={10.1109/ecce.2012.6342328}, abstractNote={This paper presents an integrated traction machine and converter topology that has bidirectional power flow capability between an electric vehicle and the DC or AC supply or grid. The inductances of the traction motor windings are used for bi-directional converter operation to transfer power eliminating the need for extra inductors for the charger and vehicle-to-grid (V2G) converter operation. The electric powertrain system size and weight can be minimized with this approach. The concept has been analyzed with finite element coupled simulation with dynamic analysis software. Experimental results are also provided with an electric machine. The interleaving technique has been used with the inductors to share the current and reduce the converter switching stresses. The proposed integrated converter can operate in the traction mode and in the bidirectional power flow mode when energy can be transferred between the vehicle and the DC or single phase AC supply.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Khan, M. A. and Husain, I. and Sozer, Y.}, year={2012}, pages={3403–3410} }