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X-WR-CALNAME:EE
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:20230101T000000
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20230304T143000
DTEND;TZID=Asia/Kolkata:20230304T223000
DTSTAMP:20260528T233920
CREATED:20230226T231315Z
LAST-MODIFIED:20230301T001554Z
UID:240474-1677940200-1677969000@ee.iisc.ac.in
SUMMARY:Open Day 4th March 2023
DESCRIPTION:Events are to be held in the Electrical Engineering Department on an open day. \nSPECTRUM  LAB DEMOS \nGenerative Models\, XAI for Optical Coherence Tomography\, AI Assisted Wireless-Capsule Endoscopy Analysis\, Neuromorphic Cameras\, Foreign Object Debris (FOD) Detection\, Real Time Human Pose Detection\,How to get into IISc?\, AI-assisted echocardiography                      Spectrum Lab at Open Day \nCOMPUTER VISION \nImage Analysis and Computer Vision Laboratory                                                                        IACV_Lab_Poster \nCONTROL SYSTEM \nReinforcement Learning Aided Efficient and Distributed Planning for Multi-Agent Systems                   cns-pt_open-day-2023 (3) \nDIGITAL SIGNAL PROCESSING \nINDIAN SIGN LANGUAGE\, AI VS HUMAN\, RPS GAME\, NON-CONTACT MEASUREMENT                    DSP Open Day Poster \nPower SYSTEM \nPOWER SYSTEM OPERATION AND CONTROL                                                   FIST_Lab_Open_Day23_Poster \nSignal Processing Interpretation and Representation (SPIRE) Lab\n\nWatch Me Speak                                                                                                      Demo1 \nMake computer speak in Indian Languages                                                             Demo2 \n Wanna be a sound engineer?                                                                                  Demo3 \nCan your breath sound reveal your gender?Mystery                                               Demo4 \nSpeed up to launch up!                                                                                             Demo5 \n Mimic your favorite actor                                                                                         Demo6 \nDo you hear what they say?                                                                                    Demo7 \nVisualize your vocals                                                                                              Demo8 \nCan you recognize correct pronunciation of an English word?                              Demo9. \nLanguage engineering and processing Lab \nAuditory perception Illusions                                                 LEAP_openday_BAI_2023 \nWho spoke when in a conversation?                                    openday_diarization_poster \nMultimodal Conversational Emotion Recognition                 open_day2023_soumya \nSound Based COVID-19 Diagnosis                                     open_day_poster2023_COSWARA \nAutomatic Speech Recognition                                            Introduction_To_ASR_Srikanth
URL:https://ee.iisc.ac.in/event/open-day/
LOCATION:EE\, IISc
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20230309T143000
DTEND;TZID=Asia/Kolkata:20230310T043000
DTSTAMP:20260528T233920
CREATED:20230308T225946Z
LAST-MODIFIED:20230309T000550Z
UID:240527-1678372200-1678422600@ee.iisc.ac.in
SUMMARY:Thesis Defense of Shubham Rawat
DESCRIPTION:Title: A Novel Passive Regenerative Snubber for the Phase-Shifted Full-Bridge Converter:  Analysis\, Design and Experimental Verification. \nResearch  Supervisor: Prof. Kaushik Basu \nMeeting Link \n\nAbstract: \nThe development of Wide Bandgap (WBG) devices has enabled power electronic converters to operate at much higher frequencies\, voltages and power. Working at a higher switching frequency minimises the size of magnetics but results in significant switching losses and electromagnetic interference (EMI) noise. Thus\, it necessitates the use of soft-switching techniques to reduce these losses. Phase-Shifted Full-Bridge (PSFB) Converter is the most widely used soft-switching topology in the high-voltage and high-power\, unidirectional DC-DC conversion. The phase shift PWM control utilises the converter parasitic to achieve zero voltage switching (ZVS) turn ON. The gating technique allows the magnetic energy stored in the leakage inductance of the isolation transformer to charge and discharge the output capacitances of the inverter leg. \n\nHowever\, the converter suffers from severe voltage overshoots across the rectifier bridge during the zero to the active state transition. The resonant circuit formed between the transformer leakage inductance and the parasitic diode capacitance of the rectifier is responsible for the high-voltage ringing.  Many passive and active snubbers are presented in the literature to mitigate the high voltage overshoots across the diode bridge. While passive snubbers are relatively simple to implement than active snubbers\, they are lossy. On the other hand\, the active snubbers require additional gate driver circuitry and complex control. \nThe first part of the thesis proposes a novel passive regenerative snubber to overcome the mentioned drawbacks of the existing snubbers. The proposed snubber is ideally lossless with no control complexity. The work covers a detailed analysis of the PSFB operation with the proposed snubber while obtaining closed-form expressions for the converter state variables at the end of each topological stage. The study considers all the major converter parasitic\, such as transformer leakage and magnetising inductances\, and parasitic capacitances of the converter. Given the new snubber\, the thesis also lays out a step-by-step PSFB design procedure utilising the analysis carried out in the first part of the work. The design aimed to develop a 100 kHz PSFB for an input voltage of 360-400 V and the output power range of 0.5-1.5 kW at a fixed output voltage of 48 V. The design approach focuses on the two design objectives. All inverter switches must achieve ZVS turn ON\, and the converter gain must achieve the necessary gain to maintain desired constant output voltage for all possible operating conditions. \nA hardware prototype is built and tested as per the given specification. The experimental results validate the effectiveness of the snubber in reducing the voltage overshoot. Further\, the analysis and design accuracy is verified using the measured state variables. Finally\, the work presents the overall efficiency and the loss distribution among the converter components.
URL:https://ee.iisc.ac.in/event/thesis-defense-of-shubham-rawat/
LOCATION:Online\, India
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BEGIN:VEVENT
DTSTART;TZID=Asia/Kolkata:20230310T163000
DTEND;TZID=Asia/Kolkata:20230313T183000
DTSTAMP:20260528T233920
CREATED:20230309T234144Z
LAST-MODIFIED:20230309T234240Z
UID:240537-1678465800-1678732200@ee.iisc.ac.in
SUMMARY:MTech (Research) Colloquium of Vishwabandhu Uttam
DESCRIPTION:Title: A Unified Modeling Approach for Design and Performance Improvement of Triple Active Bridge Converter\n\nResearch Supervisor: Vishnu Mahadeva Iyer\n\n Meeting link\n\nAbstract:Triple Active Bridge (TAB) converter is a multi-port DC-DC converter. This converter is an extension of the popular Dual Active Bridge converter. It features desirable traits of the DAB converter\, such as high power density\, galvanic isolation\, and bi-directional power flow between any of the ports. As in other multi-port converters\, redundant power conversion is minimized through component sharing among the ports in a TAB converter. All the switches in a TAB converter can undergo soft-switching over a wide range of operating points\, reducing switching losses and the size of auxiliary components. The multiple degrees of freedom in modulating a TAB converter offer several design and operational flexibilities.However\, this converter has yet to come into the limelight despite these advantages. One of the reasons is the lack of a unified analytical framework for the design and operation of this converter. The existing models for the TAB converter are limited in scope and cannot be easily used for the design and operational optimization of the converter. This work focuses on developing simple\, unified models for analyzing the TAB converter.Firstly\, the popular Fundamental Harmonic Approximated (FHA) large-signal and small-signal models are evaluated to understand their limitations. Improved large-signal and small-signal Generalised Harmonic Models (GHM) are developed by incorporating the impact of higher-order harmonics. While the GHM is shown to be superior for small-signal analysis of the converter\, it is not suitable to analyze the soft-switching bounds of the TAB converter. To overcome the limitations of GHM\, a Unified Model that incorporates the impact of the magnetising inductance of the three-winding transformer is proposed. The Unified Model can accurately predict the AC port currents at the switching instants and is used to study the soft-switching bounds of the TAB converter. The GHM and Unified Model are validated through extensive switching circuit simulations and experimental results from a 1 kW hardware prototype developed in the laboratory.Further\, a new design algorithm for the TAB converter is proposed. The proposed algorithm leverages the FHA model’s simplicity and the Unified Model’s accuracy. Finally\, a new modulation scheme based on Penta Phase Shift with five degrees of freedom is proposed to achieve soft-switching across the operational range of the TAB converter.\nWe request your presence at the colloquium.\nAll are welcome.
URL:https://ee.iisc.ac.in/event/mtech-research-colloquium-of-vishwabandhu-uttam/
LOCATION:EE\, MMCR
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DTSTART;TZID=Asia/Kolkata:20230327T210000
DTEND;TZID=Asia/Kolkata:20230327T230000
DTSTAMP:20260528T233920
CREATED:20230326T224428Z
LAST-MODIFIED:20230326T225234Z
UID:240559-1679950800-1679958000@ee.iisc.ac.in
SUMMARY:Thesis Defense of Mr. Manish Tathode
DESCRIPTION:Title:  Fast and Compact Voltage Equalizer for Satellite Applications. \nAdvisor: Prof. Vinod John.Date and Time: Monday\, 27th March 2023\, 3.30 pm.Location: EE-B304\, EE Department.Meeting Link: \nAbstract:Lithium-ion batteries have now become an inevitable constituent of the Electrical Power System of solar-powered satellites due to their high energy density\, wider operating temperature range\, and better radiation tolerance. For the compact realization and better space utilization\, the series-parallel connected Li-ion batteries are operated with currents close to the design limit of the cells\, speeding up the increase in the inherent initial imbalance in the individual cell voltages in a series-connected stack\, demanding fast equalization to avoid underutilization and reduced lifetime. Active multicell-to-multicell equalization achieves fast equalization by efficient simultaneous charge transfer among multiple cells in the series connected stack. PS-MAHB equalizer is one such multicell-to-multicell equalizer with the ability to maintain higher equalization currents irrespective of decreasing differences in the cell voltages. Its open loop\, soft-switched operation\, and modularization abilities make it an attractive choice for space applications. However\, it needs to be modified with the necessary protective features and required redundancy essential for its use in space applications. Hence\, the Modified PS-MAHB (M-PS-MAHB) equalizer is developed by incorporating necessary protection features and redundancy in the PS-MAHB equalizer. The flow of development of M-PS-MAHB equalizer is discussed. The Failure Mode Impact Analysis of the M-PS-MAHB equalizer reveals that during the most likely switch short circuit failure mode\, the faulty part of the equalizer is disconnected by the protective device and the redundancy does not let the cell get out of the equalization. Simulation results of FMIA considering transient and steady state impact of the failure are discussed.The existing static phase shift-based control of the equalizer causes direct dependency of the equalization currents on the cell voltages and limits the equalization current levels to lower than the design equalization current value when the cell voltages are lower. Thus\, the control works with a reduced rate of equalization and causes the under-utilization of the equalizer hardware for a significant duration of time in the charge-discharge cycle. A dynamic phase shift-based control is proposed to maximize the equalization current through the cells irrespective of the cell voltages which further increases the rate of equalization and improves the equalizer hardware utilization. In the simulation\, a significant improvement in the equalization rate compared to the static phase shift control is verified with the proposed dynamic phase shift-based control.The compact hardware realization of the equalizer hardware and the voltage sensor board addresses the space-volume constraints put by satellite applications. The equalizer hardware is realized as 4-cell equalizer modules\, and the compactness of the equalizer hardware is achieved by pushing the switching frequency to 1MHz reducing the values of the passive components. A non-isolated high-precision op-amp-based voltage sensing scheme is developed to target the equalization band close to 10mV. The concept of an easy-to-design motherboard-based interface is introduced\, which does not require any changes in the design of the 4-cell equalizer module and the voltage sensor board\, irrespective of the cell connector geometry.The experimental results verify the operation of the equalizer demonstrating the convergence of cell voltages from the initial imbalance of 300mV to the band of 10mV. The impact of the non-ideal dynamic response of the Li-ion cell voltage to a step change in current and its impact on the voltage-sensing-based control algorithm is discussed along with the necessary modifications brought in the control to reduce the impact.We request your presence at the thesis defence.
URL:https://ee.iisc.ac.in/event/thesis-defense-of-mr-manish-tathode-330pm/
LOCATION:EE-B304\, EE Department.
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