@article{safayet_islam_sebastian_2022, title={Comprehensive Analysis for DC-Link Capacitor Sizing for a Three-Phase Current-Controlled Voltage-Source Inverter}, volume={58}, ISSN={["1939-9367"]}, DOI={10.1109/TIA.2022.3175167}, abstractNote={An analytical approach to size a dc-link capacitor for a three-phase current-controlled voltage-source inverter used for a permanent magnet synchronous motor is presented in this article considering the dc-link ripple voltage and capacitor ripple current. The analytical method derived in this article shows the variation of the dc-link voltage ripple with the change of the power factor and the modulation index. This analysis can be applied to determine the maximum possible ripple voltage for a given capacitor or the minimum capacitance needed to keep the voltage ripple under a limit. Then, current ripple analysis is used to determine the root-mean-square capacitor ripple current taking account of the thermal duty cycles of the application. Finally, capacitor life estimation analysis is used using the operating condition, thermal duty cycle, and ripple current to determine the capacitor end life for a given application. The research presents a sequential process to select a dc-link capacitor accounting for the electrical and thermal requirement of the system. The analysis is verified by simulation and experimental results, where the effect of components’ parasitic on the voltage and current ripple is presented.}, number={4}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Safayet, Ali and Islam, Mohammad and Sebastian, Tomy}, year={2022}, pages={4248–4260} }
@inproceedings{safayet_fajri_husain_2015, title={Reactive power management for overvoltage prevention at high PV penetration in low voltage distribution system}, DOI={10.1109/ecce.2015.7309941}, abstractNote={In this paper, a new approach for reactive power management based on inverter's capacity and sensitivity to the critical bus has been presented. The approach addresses the voltage rise and reverse power flow issue when residential renewable energy sources such as rooftop solar panels produce more energy than the local load demand. The overvoltage issues are controlled by active management of reactive power flow. This method improves the voltage regulation of distributed system with high penetration of renewable energy sources while utilizing the inverters' reactive power capacity.}, booktitle={2015 ieee energy conversion congress and exposition (ecce)}, author={Safayet, A. and Fajri, P. and Husain, I.}, year={2015}, pages={1988–1994} }
@inproceedings{alkuhayli_safayet_husain_2015, title={Single-phase distributed generation synchronization with a distorted or weak grid}, DOI={10.1109/ecce.2015.7309819}, abstractNote={Fast and accurate synchronization of power electronics interfaced distributed generation to the grid or a microgrid is an important step in the management and utilization of the distributed energy resources. Several synchronization algorithms have been proposed to improve the phase tracking of the grid voltage. However, when the grid is weak or distorted, the synchronization process may suffer from poor frequency regulation. Therefore, Sliding Discrete Fourier Transform Phase-locked-loop (SDFT-PLL) algorithm is proposed to extract an accurate angle of the fundamental voltage while rejecting the harmonics in a distorted or weak grid. The SDFT-PLL algorithm and simulation results to validate this method are presented in this paper.}, booktitle={2015 ieee energy conversion congress and exposition (ecce)}, author={Alkuhayli, A. and Safayet, A. and Husain, I.}, year={2015}, pages={1143–1148} }
@article{elrayyah_safayet_sozer_husain_elbuluk_2014, title={Efficient Harmonic and Phase Estimator for Single-Phase Grid-Connected Renewable Energy Systems}, volume={50}, ISSN={["1939-9367"]}, DOI={10.1109/tia.2013.2266392}, abstractNote={Renewable energy sources (RESs) in any power system can participate in removing the harmonics from the line voltage, but the RESs need to estimate these harmonics first. In this paper, an efficient method to estimate grid harmonics is proposed to be used by single-phase RESs. The proposed method provides accurate estimation for the harmonics while it has lower computation complexity than the other existing methods. To make the harmonic estimation process fast and accurate, the harmonics in the sampled grid voltage is eliminated before passing it to the phase-locked-loop block used for estimating the grid phase. Another application of the proposed method is to transform single-phase voltage or current from the stationary reference frame into the dq rotating reference frame. In this application, the use of the proposed method eliminates the need of generating fictitious voltage or current waveforms orthogonal to the measured quantities. The elimination of need to generate fictitious waveforms speeds up the transformation transients and reduces the operations to less than half of those required by traditional methods. Simulation and experimental results verified that the algorithm achieves fast and accurate harmonic estimation of highly distorted grid voltage.}, number={1}, journal={IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS}, author={Elrayyah, Ali and Safayet, Ali and Sozer, Yilmaz and Husain, Iqbal and Elbuluk, Malik}, year={2014}, pages={620–630} }
@inproceedings{safayet_husain_elrayyah_sozer_2013, title={Grid harmonics and voltage unbalance effect elimination for three-phase PLL grid synchronization algorithm}, DOI={10.1109/ecce.2013.6647133}, abstractNote={The conventional synchronous reference frame phase locked loop (SRF-PLL) works perfectly for synchronization of utility interactive systems with grid that has no imperfections such as harmonics, unbalanced voltage or frequency fluctuation. However, the power grid suffers from these types of imperfections. For large distributed systems such as solar, onshore and offshore wind or wave energy, there is a need for synchronization with the frequency and phase angle of the three-phase grid contaminated with harmonics. For three-phase systems, the other imperfection of the grid that needs to be eliminated before feeding the grid voltage to PLL is the voltage unbalance. The proposed algorithm demonstrates a method to eliminate both the three-phase grid voltage harmonics and unbalance effects to improve the steady state performance of grid synchronization with high bandwidth PLL.}, booktitle={2013 ieee energy conversion congress and exposition (ecce)}, author={Safayet, A. and Husain, I. and Elrayyah, A. and Sozer, Y.}, year={2013}, pages={3299–3304} }
@inproceedings{safayet_husain_sozer_2013, title={Reactive power scheduler for voltage regulation of distributed energy systems}, DOI={10.1109/ecce.2013.6647092}, abstractNote={A new reactive power scheduler control algorithm for the distributed voltage regulation with PQ inverters is proposed in this research. An elegant approach to achieve voltage regulation in utility grid is proposed through appropriate control of the renewable energy systems. PQ inverter capable of producing the reactive power is used to either achieve local voltage regulation or produce the reactive power commanded from the outer voltage regulator in the upper hierarchy of the grid management system. The proposed PQ scheduler and PQ inverters will work harmoniously in the local substation with minimum communication interface. The proposed control techniques achieve efficient utilization of the PQ inverters with maximum efficiency. The proposed energy network and the control algorithms are modeled at the system level to verify the effectiveness of the proposed system architecture.}, booktitle={2013 ieee energy conversion congress and exposition (ecce)}, author={Safayet, A. and Husain, I. and Sozer, Y.}, year={2013}, pages={2996–3002} }
@inproceedings{agamloh_husain_safayet_2012, title={Investigation of the electrical system design concept and grid connection of ocean energy devices to an offshore compressed energy storage system}, DOI={10.1109/ecce.2012.6342377}, abstractNote={One of the biggest challenges of ocean wave and wind energy systems is the mitigation of the intermittency effects, in order to allow for their integration into the electric grid. Energy extraction using an ocean based compressed air energy storage system (OCAES) is proposed to enhance the economic dispatch of these energy sources onto the grid. There are land based compressed air energy systems storage systems. The ocean based version is a relatively new concept that is not proven and has not been studied in detail, yet it has significant advantages over the land based systems. The focus of the paper is on the power transmission and grid control utilizing the OCAES. System design concepts are discussed and simulation results are provided.}, booktitle={2012 IEEE Energy Conversion Congress and Exposition (ECCE)}, author={Agamloh, E. B. and Husain, I. and Safayet, A.}, year={2012}, pages={2819–2826} }