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X-ORIGINAL-URL:https://ee.iisc.ac.in
X-WR-CALDESC:Events for EE
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TZID:Asia/Kolkata
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TZOFFSETFROM:+0530
TZOFFSETTO:+0530
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DTSTART:20240101T000000
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241107T153000
DTEND;TZID=Asia/Kolkata:20241107T170000
DTSTAMP:20260526T183527
CREATED:20241106T093622Z
LAST-MODIFIED:20241107T043721Z
UID:241811-1730993400-1730998800@ee.iisc.ac.in
SUMMARY:Talk on Design of a Robust Power Hardware-in-the-Loop Interface Controller and an Enhanced Droop Control for Seamless Transfer
DESCRIPTION:Title:  Design of a Robust Power Hardware-in-the-Loop Interface Controller and an Enhanced Droop Control for Seamless Transfer \n  \nSpeaker: \nDr. Soham Chakraborty \nPostdoctoral Researcher\nEnergy Systems Integration Facility\,\nNational Renewable Energy Laboratory\,\nGolden\, Colorado\, USA 80401\nDate: 7th November 2024\, 3:30 PM \n  \nVenue: C 241\, MMCR\, EE Dept\, IISc \nJoin the meeting now \n  \n\n Abstract: \nIn the first part of the talk\, the challenges of synthesizing an interface between the hardware and software components of PHIL will be discussed and talked about from a modern control perspective for managing inherent uncertainties. The proposed robust PHIL interface controller based on mu-synthesis ensures multiple objectives that includes robust stability\, performance\, accuracy\, and tracking capabilities. To assess the effectiveness and viability\, a PHIL experiment is conducted that involves interfacing an emulated software system based on a 1-φ\, 225-bus\, 110V\, 60Hz\, 1MW residential sub-network of the University of Minnesota and suburban Minneapolis interfaced with multiple hardware under tests. \n\nIn the second part of the talk\, a seamless transition strategy using a single and unified mode-dependent droop-controlled grid-forming inverters will be discussed. Seamless recovery of power to critical infrastructures\, after grid failure\, is a crucial need arising in scenarios that are increasingly becoming more frequent. The proposed control strategy regulates the output active and reactive power by the inverters to a desired value while operating in on-grid mode; seamless transition and recovery of power injections into the load after grid failure by inverters that operates in grid-forming mode all the time; and requires only a single bit of information on the grid/network status for the mode transition. A hardware experiment is conducted with two 3-φ\, 480-V\, 125-kVA grid-forming inverters\, a 3-φ\, 480-V\, 270-kVA grid simulator\, a physical grid switch\, and a physical load bank.\n\n \nShort Biography:\nSoham Chakraborty received the B.E. degree from Bengal Engineering and Science University\, Shibpur\, India\, in 2013\, the M.Tech. degree from the\nIndian Institute of Technology\, Mumbai\, India\, in 2016\, and the PhD degree from the  the University of Minnesota\, Minneapolis\, MN\, USA in 2023; all in electrical engineering. The title of his PhD thesis was “Robust Dynamic Resilient Power Grids Enabled By Modern Control Framework”.\nHe is currently working as a Post-Doctoral Fellow at the Energy Systems Integration Facility\, National Renewable Energy Laboratory\, USA from 2023.
URL:https://ee.iisc.ac.in/event/talk/
LOCATION:MMCR\, Hall C 241\, 1st floor\, EE department
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241108T140000
DTEND;TZID=Asia/Kolkata:20241108T150000
DTSTAMP:20260526T183527
CREATED:20241108T061637Z
LAST-MODIFIED:20241108T061637Z
UID:241817-1731074400-1731078000@ee.iisc.ac.in
SUMMARY:[Talk] End-to-End Modeling for Abstractive Speech Summarization\, Dr Roshan Sharma\, Google USA\, November 8 (today)\, 2-3 pm
DESCRIPTION:TITLE: End-to-End Modeling for Abstractive Speech Summarization\n\nTIME AND VENUE: MMCR\, EE\, C241\, 2:00-3:00 pm\n\nABSTRACT\nIn our increasingly interconnected world\, where speech remains the most intuitive and natural form of communication\, spoken language processing systems face a crucial challenge: they must do more than just categorize speech\, they need to truly understand it to generate meaningful responses. One key aspect of this understanding is speech summarization\, where a system condenses the important information from spoken input into a concise summary.\n\nIn this talk\, I will discuss our work on end-to-end modeling for abstractive speech summarization\, and expound on our work in long-context modeling\, multi-stage training\, open source datasets and benchmarks\, and finally studies about the impact of various factors on human annotations.\n\n\nSPEAKER BIO:\nRoshan Sharma is a Research Scientist with Google in New York\, USA. He earned his Ph.D. in March 2024 from Carnegie Mellon University\, USA for his thesis titled “End-to-End Modeling for Abstractive Speech Summarization”. He has diverse experiences across multiple areas of speech and language processing\, including speech recognition\, spoken language understanding\, noise suppression\, multimodal machine learning\, and more recently in large-scale foundation models.
URL:https://ee.iisc.ac.in/event/talk-end-to-end-modeling-for-abstractive-speech-summarization-dr-roshan-sharma-google-usa-november-8-today-2-3-pm/
LOCATION:MMCR\, Hall C 241\, 1st floor\, EE department
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20241111T150000
DTEND;TZID=Asia/Kolkata:20241111T170000
DTSTAMP:20260526T183527
CREATED:20241028T052528Z
LAST-MODIFIED:20241028T052528Z
UID:241806-1731337200-1731344400@ee.iisc.ac.in
SUMMARY:PhD Defense
DESCRIPTION:NAME OF THE STUDENT:     Meenu Jayamohan \nDEGREE REGISTERED      :     PhD \nADVISOR                            :    Dr. Sarasij Das \nDATE                                  :    11th November 2024 \nTIME                                  :    3:00 PM \nVENUE                               :    C 241\, MMCR\, Electrical Engg Dept \nMeeting Link                    :   Click Here for Link   \n\n ———————————————————————————————- \nTitle: Power Swing Blocking Protection in Presence of Large Scale Grid Following PV Generation    \n——————————————————————————– \nAbstract:   \nThe penetration of Inverter-Based Resources (IBRs) is increasing in power grids due to environmental concerns. The fault behaviour of IBR is quite different than that of Synchronous Generators (SGs). In addition\, IBRs usually do not have inherent inertia. As a result\, the existing protection schemes\, which are traditionally developed for SG-dominated systems\, can become ineffective. Stable power swings (SPS) and Unstable Power Swings (UPS) caused by oscillations generated during system disturbances may trigger undesired relay operations. Power swing Blocking (PSB) and Out-of-Step Tripping (OST) techniques have been employed to stop distance relays from malfunctioning during SPS and UPS\, respectively. PSB schemes commonly use the magnitude of the rate of change of positive sequence impedance (|dZ/dt|) for SPS detection. This research work focuses on the PSB protection issues in the \npresence of large-scale Grid-Following (GFOL) PV generation. A modified IEEE-39 bus system is used for all the studies presented in this thesis.\n\nAs the converter controls determine how PV generators behave during transients\, the behaviour of SGs used in conventional power systems differs significantly from that of PVs. As a result\, existing protection methods\, including PSB methods\, must be modified to protect the IBR-integrated power systems. This work examines how integrating GFOL PV generation affects power swing impedance (Z) trajectories and |dZ/dt|. The research reveals that the\nGFOL PV systems can significantly alter the Z trajectories observed during power swings compared to that of an SG-dominated system. The results presented demonstrate that the penetration of GFOL PV may increase the speed of Z trajectories and\, hence\, |dZ/dt|\, which may\, in turn\, cause maloperations of the PSB and OST functions. The findings emphasize the critical need to revisit and potentially adapt existing PSB and OST schemes to account for the growing presence of IBRs in power grids.\n\nIn the GFOL control strategy\, the injected power is controlled with respect to the grid voltages measured at the terminal by the Phase-Locked Loop (PLL). Considering a PLL bandwidth in the range of 2−15 Hz for a weak grid\, the PLL dynamics play a significant role in the power swing dynamics. In this work\, the impact of various types and control parameters of PLLs on |dZ/dt| and Z trajectories are analyzed using mathematical analysis. Synchronous Reference Frame PLL with additional Low pass filter (LSRF PLL)\, Multiple Reference Frame (MRF) PLL and Dual Second-Order Generalized Integrator (DSOGI) PLL are used for the study. The impacts of varying penetration of PV and relay locations are also investigated. This study shows that the PLL parameters and bandwidth influence the operation/maloperation of the PSB during SPS.\n\nDuring Fault Ride-Through (FRT)\, the PV system can provide additional reactive power to the grid to maintain the voltage at its terminals. This is achieved through the dynamic voltage or reactive power support and is provided in proportion to the drop in terminal voltage using the K-factor. The study also highlights the importance of considering the active power recovery rate to mitigate the oscillatory behaviour of IBR during the fault recovery process. The findings reveal that\, following fault removal\, the dynamic behaviour of inverters would be significantly influenced by both the K-factor and the active power recovery rate\, which may affect the power swing characteristics. This work emphasizes the need for a comprehensive understanding of how dynamic voltage support features and active power recovery interact with the power swing dynamics and influence PSB operation.\n\nAuto-Reclosing (AR) of a circuit breaker is a technique that attempts to re-energize the faulted line after a predetermined time delay. While IEEE Std C37.104-2012 provides guidelines for minimum AR dead time based on arc de-ionization\, these may not be sufficient for grids with a high penetration of IBRs. This work explores how varying the three-phase AR dead time can influence the severity of power swings that may occur after consecutive Low-Voltage Ride-Through (LVRT) events in a GFOL PV plant. This finding highlights the potential need to revise\nexisting minimum AR dead time standards for grids with high IBR penetration levels to ensure reliable system operation.\n\nThe studies presented in the previous sections show that existing impedance-based PSB methods might fail in the presence of GFOL PV generation. The lack of inherent inertia of the GFOL PV is one of the reasons behind the increased |dZ/dt| which may cause maloperation of the existing impedance-based PSB schemes. Hence\, a novel PSB method is proposed\, which uses nodal inertia to re-evaluate the |dZ/dt| values. The effectiveness of the proposed method is verified for both the SG-dominated system and the GFOL PV-integrated system using PSCAD simulations.
URL:https://ee.iisc.ac.in/event/phd-defense/
LOCATION:Multi-Media Class Room (MMCR)\, EE Department (Hybrid mode)
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