Institutional Digital Repository (Indian Institute of Technology Kharagpu)

Reddy, Gudur Balawanth

PARAMETER ADAPTATION OF INDUCTION MACHINE DRIVE FOR 
INDUSTRIAL APPLICATION 
Abstract: 
This thesis focuses on a few real-life industrial problems of squirrel-cage induction-machine 
drive with a speed sensor and their solutions for improved steady-state and dynamic performances. 
The performance of a sensor-based rotor flux-oriented vector control induction machine drive is 
dependent on the accuracy of the machine parameters, used in the machine model of the controller. 
A study on the steady-state and dynamic performance of the drive due to the variation of the 
machine parameter is carried out. A mathematical expression is derived to assess the sensitivity of 
the models of electromagnetic torque and rotor flux to the possible variation of the machine 
parameters. The need for online adaptation of the critical machine parameter like rotor time 
constant is established in the thesis to achieve accurate control over the electromagnetic torque. 
This thesis proposes a novel and simple algorithm to estimate and adapt the rotor time constant, 
online, for a speed sensor-based field-oriented vector control drive. A current-based model is used 
to compute the rotor flux vector for the torque controller and another voltage-based model is used 
to estimate the rotor flux vector for the reference. The error between these two rotor flux vectors 
is minimized using the least-square method. In this process, the rotor time constant gets tuned to 
its actual value. The thesis also presents a simple technique to estimate the remaining parameters 
of the induction machine like the stator resistance, the net leakage inductance of the machine, and 
the initial guess of the rotor time constant in offline mode at standstill.  
Results from two practical field studies on industrial drives are presented in this thesis, 
emphasizing the online adaptation of the rotor time constant and the self-commissioning. 
Additionally, a synchronous PWM technique and dead-time compensation technique for a two-
level inverter are also included in this thesis as they are developed for these industrial studies. In 
traction drives, during over-modulation, the reduction in the number of switching pulses per 
fundamental cycle introduces low-frequency sub-harmonics currents. This results in pulsating 
torque and increased machine losses. This can be improved by adapting the synchronous PWM 
technique. In this thesis, a simple technique has been proposed to synchronize the carrier signal 
with the modulating signal using the instantaneous angular position of the traction drive. In this 
thesis, the effect of dead time has also been demonstrated and a simple dead-time compensation 
technique has been implemented for the high-power industrial drive. 
Keywords: Induction machine drive, parameter sensitivity, parameter estimation, adaptation of 
rotor time constant, traction drive, synchronous PWM, dead-time compensation. 


Parameter Adaptation of Induction Machine Drive for Industrial Application

Mondal, Jayanta

Development of Wear Resistant Carbide-Free Bainitic and Martensitic Steels

Reddy, Ravula Sudharshan

Radiation Energy Analysis in Baking Oven and Solution of Inverse Heat Transfer Problem for Estimating Energy Consumption by Bread

Hemanth, Chaduvula

Optimal Energy Management in Different Operating Modes of AC Microgrid under Uncertainties

Pal, Shreya

An Empirical Investigation of Economic Globalisation and Financial Development Nexus in Developing Regions

Mallick, Mohidul Alam

Decision Support Framework for Boomerang Hiring in Indian IT Sector

Mahato, Jagannath

Flow Instabilities Inside a Nozzle

Narendr, Aishwarya

 Aishwarya Narendr (18ID91R01)        Abstract  
 
Flood Resilient Scenario Modelling (FReSMo): for assessing coastal 
flood impact of built infrastructure 
Coastlines have played an instrumental role in the progression of human settlement due to various 
economic and ecological benefits. However, the rapidly changing climate is foreboding for both 
coasts and coastal settlements. Coastal extremes like tidal anomalies and storm surges are becoming 
more frequent, damaging built infrastructure and jeopardising coastal sustainability. Ninety-two 
percent of the world population under the severe threat of the 100-year flood lives in South and East 
Asia, mostly in China (329 million) and India (225 million). Developing nations with increased mean 
sea levels, a high density of marginalized populations near the coastline, and inadequate capacities 
for mitigating flood risk are suffering from negative consequences of climate change. About 95% of 
India's climatic extremes occur along its 7500-kilometer coastline consisting of 3288 fishing 
communities. However, such marginal communities cannot move since they depend on coastal 
regions for revenue. Thus, climate change adaptation is beneficial for resilient regional development. 
Recurring floods would destroy the local economy without a climate-resilient policy. 
India's National Action Plan for Climate Change (NAPCC) has associated the loss of residential 
structures as the primary impact of prolonged flooding, affecting coastal welfare. Cyclones Bulbul 
(2019), Aamphan (2020), and Yaas (2021) destroyed 3.44 million dwelling units in affected districts 
of West Bengal. Despite the loss, coastal flood impacts on buildings are rarely prioritised in 
developing countries due to their resource-intensive nature, lack of aboriginal damage catalogues or 
damage records, and discrete behaviour based on building typology, which prevents the adaptation 
of foreign damage curves on native buildings. Investing in flood-resilient housing requires calculating 
flood damage costs for economic assessments and optimum resource allocation for Building Back 
Better (BBB). Thus, this research seeks to prove Flood Resilient Scenario Modelling (FReSMo), an 
innovative method for designing realistic flood resilience solutions in impoverished nations.  
The current research examines an analysis, understanding, and solution-based methodology. During 
the analysis phase, the thesis had to identify and comprehend the risk profile of Sagar Island, West 
Bengal, India. In eight years, the island's built-up class has increased from 1.7% to 3.6%. (2012–
2020). The area under water rose from 6.6 to 8.6%, indicating clear evidence of a coastline breach. 
72 percent of households on the island are semi-permanent, with a low rate of literacy and 
infrastructural connection, making them extremely sensitive to flood risk. The regional hazard and 
vulnerability maps provide the overall risk map. The findings reveal the dominance of economic and 
accessibility parameters in defining vulnerability, which will increase further due to changes in 
climate, population, and landscape dynamics. 
The second part is to understand the flood behaviour of prominent building typologies in Sagar Island 
through a self-designed multivariate damage matrix. In the literature-based approach, the damage 
behaviour of mud buildings is predicted using logical assumptions based on the available scientific 
evidence. The laboratory-based technique examines flood effect via real-time exposure in an 
experimental scenario. A "multivariate damage matrix" represents flood depth and duration-related 
losses. It estimates damage stage variation using Monte Carlo simulations of synthetic flood data, 
showing its adaptability in spatio-temporal (flood character and intensity) applications. 
The final portion of the thesis recognises IPCC-defined Nature Based Solutions as the best possible 
local adaptation method for flood-resilient development in developing nations. Each key of Source – 
Pathway – Receptor – Consequence incorporates dynamic flood risk assessment. The flood return 
 Aishwarya Narendr (18ID91R01)        Abstract  
period and relative sea level rise simulate the coastal flood exposure following a high tide occurrence. 
Peak over Threshold with Generalized Extreme Value calculates the flood return period. Using 
population, physiographic, socio-demographic, and economic characteristics, FUTURES (FUTure 
Urban-Regional Environment Simulation) model predicts 2050 built-up expansion. The integration 
of flood exposure and built-up provides a picture of the probable damage in each scenario. Finally, 
the flexible multivariate damage model interprets the financial loss from the damaged building. The 
loss estimates are used to calculate the cost-benefit ratio of mangroves in terms of reducing building 
vulnerability and protecting coastal sustainability. A 100m mangrove patch along the perimeter 
reduced building damage costs by 70% for 48-hour flooding and 75% for 24-hour flooding. Thus, 
FReSMo provides a comprehensive approach for disaster-related research in developing countries 
that goes beyond regional risk assessment. Scenario-based impact assessment using the new damage 
matrix idea gives FreSMo a repeatable diagnostic viewpoint for comparable items at risk. Finally, 
DRR investments' cost-effectiveness can be proven post-disaster, making them unmatched. 
Keywords: Climate change, Coastal flood risk, Cost-benefit analysis, Flood damage matrix, Flood 
return period, Nature Based Solution, Sea level rise. 
- Aishwarya Narendr 
 
 
 
 
 


Flood Resilient Scenario Modelling (Fresmo) for Assessing Coastal Flood Risk of Built Infrastructure

Gupta, Tulika Rudra

Inference on a New Stress-Strength Index for Exponential Populations

Mukhopadhyay, Anurup

Biomimetically Patterned Smart scaffolds for Tissue Engineering and Wound Healing 
 
Anurup Mukhopadhyay 
Senior Doctoral Research Fellow, School of Medical Science and Technology, IIT Kharagpur 
Roll Number: 17MM92R01 
 
Abstract 
This thesis deals with critical and rudimentary issues in polymer material property stabilization, nature-
inspired biophysical cue-mediated drug delivery and contact guidance in cell-matrix interaction, and 
the development of a cell-type independent diabetic wound healing scaffold. The prudent attributes of 
cutaneous wound healing scaffolds emerge to switch from a solitary cellular growth-supporting model 
to a comprehensive one that can promote quick healing with minimum scar formation. To fulfil this, a 
scaffold should always provide holistic support to the tissue microambience at the wound bed by starting 
the release of growth factors, initiating rapid cellular influx, setting angiogenesis in motion, augmenting 
granulation tissue formation, and maintaining an infection-free environment. To develop such a 
scaffold, the selection of appropriate biomaterials and fabrication techniques is important. In Chapter 
2, optimization of the material properties of alginate has been reported. Dual cross-linking using 
calcium chloride and maleic anhydride is accomplished, which curbs the age-old problem of alginate’s 
erratic degradation, and an optimized concentration of honey has been incorporated into the hydrogel, 
which becomes a healing substrate. In vivo experiments using a murine wound model prove this 
hydrogel to be an acute wound healing tool. However, to achieve diabetic wound healing, external 
guidance to the cells for proliferation and migration is needed, for which biomimetic biophysical cues 
have been introduced using soft lithography and freeze-drying on honey-embedded silk fibroin 
scaffolds in Chapter 3. We show that the rose petal-inspired hierarchical surface structures on the porous 
silk fibroin scaffolds can increase proliferation, mesenchymal to epithelial transition, and multilineage 
trans-differentiation of adipose-derived mesenchymal stem cells while restraining their senescence. In 
Chapter 4, we report the influence of these hierarchical structures on fibroblast behavior and model the 
cell-matrix cross-talk. The micro-nano features present on the ampicillin-loaded silk fibroin porous 
scaffold provide biophysical cues to the fibroblasts' sensors, which help the cells form a continuous 
monolayer. Topographic patterns also render the porous silk fibroin scaffold surface hydrophobic 
without any chemical functionalization, which in turn makes multiple-dose controlled drug release 
possible. In Chapter 5, in vivo studies have been conducted in a cutaneous excisional diabetic wound 
murine model to investigate the chronic wound healing efficacy of our developed scaffold. Upon 
treating full-thickness excisional diabetic wounds with the scaffolds, the wound closure kinetics, 
ultrastructural changes of the skin due to healing, and protein and gene expressions have been studied 
using different modalities, such as stereozoom microscopy, optical coherence tomography, scanning 
electron microscopy, histopathology, immunohistochemistry, immunofluorescence, and quantitative 
real-time polymerase chain reaction. Interestingly, the rose petal-patterned, replenishable, and 
controlled ampicillin-delivering porous silk fibroin scaffold has been able to achieve regenerative 
healing of a full-thickness cutaneous excisional diabetic wound in 20 days from the day of wound 
creation. Finally, Chapter 6 concludes with a summary of the whole doctoral work and the future scope 
of work for the present research. 
Keywords: Dual-crosslinking, Honey-silk fibroin, Soft lithography, Biomimetic patterning, 
Biophysical cues, Cell-matrix cross-talk, Controlled and replenishable drug delivery, Diabetic wound 
healing 


Biomimetically Patterned Smart Scaffolds for Tissue Engineering and Wound Healing

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