Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

&nbsp;

IIT Palakkad

Increase in the deployment levels of inverter-interfaced renewable energy resources (IIRERs) in the existing power systems have increased concerns among the protection engineers regarding the reliable operation of classical protection schemes presently existing in the system. This paper aims to do a comprehensive performance evaluation of directional relaying philosophies. In this regard, both the inverter control scheme along with the sequence based directional relaying schemes (SBDRS) are modeled in detail in PSCAD environment. The unpredictability observed in the values of sequence component contributions from IIRERs during faults have led to the mal-operations of SBDRS to correctly identify the direction of fault. A comparative assessment of the performance of SBDRS have been done considering contributions from conventional generators and IIRERs, in the presence and absence of grid codes. The performance of positive sequence based directional relaying scheme improves with the inclusion of grid codes with inverter control used being positive sequence current control. The performance of negative sequence based directional relaying scheme mal-operates whereas the performance of zero sequence based directional relaying scheme is dependent on interconnecting transformer connection and type of fault. © 2023 IEEE.

World University root node

Department of Electrical Engineering

2023 2nd International Conference for Innovation in Technology, INOCON 2023

A Comprehensive Performance Evaluation of Sequence Component based Directional Relaying Philosophies for Inverter Integrated Power System

This letter proposes a technique for estimating the damping ratio and frequency of oscillatory modes with high accuracy. Traditional linear techniques such as the Prony Analysis (PA), matrix pencil (MP) method and Eigensystem realization algorithms (ERAs) are used to accurately estimate the damping ratio and damped frequency of the oscillatory modes through a window selection algorithm. The letter ensures the best damped (positive or negative) sinusoid representation of the modal components of the oscillatory power signals observed by the phasor measurement unit (PMU) through the consensus of traditional linear techniques applied to various scenarios from Kundur two-area system, ISO-NE and WECC 179 bus system. © 1963-2012 IEEE.

IEEE Transactions on Instrumentation and Measurement

Linear Estimation of Low-Frequency Modal Oscillations Parameters Through Nonlinear Characterization

This article evaluates the performance of a signal similarity index (SSI) based relaying scheme for fault detection in lines connected to inverter-based resources (IBRs). During fault events, the IBRs respond differently than conventional synchronous machine based sources. Due to various control schemes and power electronic protection implemented for IBRs, fault current is limited leading to failure in fault detection and isolation by traditional protection methods. In this article, six different SSIs are calculated using time-domain current signals at both the ends of the protected line and the performance of SSI-based line protection philosophy is evaluated for various operating conditions. The relaying schemes are extensively tested on two different test systems. The test results are utilized to perform a comparative assessment of the SSI-based protection scheme. The tradeoff between the performance of the relaying scheme based on processing time, fault resistance, threshold selection, presence of noise and presence of missing data are demonstrated thoroughly on three different test systems. © 2007-2012 IEEE.

IEEE Systems Journal

Assessment of Signal Similarity Index Based Line Protection Scheme for Systems With Inverter Based Resources

Modern wearable or portable health monitoring devices are capable of photoplethysmogram (PPG) sensing, processing, analyzing, storing and transferring signal and parameters wirelessly but are generally energy constrained and have more false alarms under noisy PPG recordings. In this paper, we present computationally-efficient reliable pulse rate (PR) estimation in compressed sensing (CS) domain. The proposed CS-PPG based PR estimation method consists of measurement generation, high-pass filtering, average magnitude difference function (AMDF) features based signal quality assessment (SQA), and AMDF based quality-aware PR estimation. The proposed unified framework is evaluated using a wide variety of normal and pathological PPG signals taken from five standard databases. The proposed framework had an average sensitivity (SE) of 98.75% and specificity (SP) of 63.35%. Results show that the CS-PPG based quality-aware PR estimation method had a mean absolute error (MAE) of 3.1 ± 4.6%, Bland-Altman ratio (BAR) of 9.2% and root-mean-square error (RMSE) of 5.6 which are not only comparable with the results of the PR estimation method with the original PPG signals but also the proposed framework reduces 80% of the overall computational load. The proposed unified framework has great benefits in reducing processing time and energy consumption and thus can maximize battery lifetime of battery-operated health monitors. © 2023 IEEE.

15th International Conference on Electronics, Computers and Artificial Intelligence, ECAI 2023 - Proceedings

Fast Quality-Aware AMDF Based Pulse Rate Estimation from Compressed PPG Measurements for Wearable Vital Signs Monitor

In recent years, memristive neuromorphic systems have gained significant attention. In our previous work, we developed a physics-based framework to model transport in electrochemical metallization (ECM)-based memristors with layered materials as switching layers, which was implemented in VerilogA. In this work, we demonstrate the efficacy of this model in a crossbar array/neural network for pattern classification. The performance of the system is analyzed based on classification accuracy in ideal and non-ideal conditions. Through the use of these simulations, the system-level performance can be predicted, along with its potential degradation, owing to variability. © 2023 IEEE.

PRIME 2023 - 18th International Conference on Ph.D Research in Microelectronics and Electronics, Proceedings

Variability-aware electrochemical metallization based memristive neural network for pattern classification

A novel multifunctional frequency selective surface (FSS) based switchable absorber&#x002F;reflector is demonstrated. The design consists of a resistor-loaded resonating patch, p-i-n diodes loaded inductive grid (IG) printed on different substrates and a ground plane separated by air spacers. In the diode&#x0027;s <sc>on</sc> state, it works as a wideband absorber from 2.30 to 5.95&#x00A0;GHz &#x005B;88.48&#x0025; fractional bandwidth (FBW)&#x005D; and 3-dB reflector at different air-spacers thicknesses between FSS and IG. It also behaves as a band-notch absorber at 3.5&#x00A0;GHz (sub-6&#x00A0;GHz) and a perfect reflector for a similar configuration in the diode&#x0027;s <sc>off</sc> state. In the absence of the ground and air spacers, it works as a spatial bandpass filter with a 3-dB insertion loss from 5.50 to 7.58&#x00A0;GHz and a bandstop filter with a transmission zero at 4.5&#x00A0;GHz (3-dB return loss with 124.65&#x0025; FBW) for the <sc>on</sc> and <sc>off</sc> conditions, respectively. The design periodicity is compact (0.068&#x00A0;&#x00D7;&#x00A0;0.068<inline-formula><tex-math notation="LaTeX">${\bm{\lambda }}_{\bm{L}}^2$</tex-math></inline-formula>) and performance is obliquely stable. The authors strongly believe that the proposed design performs multiple operations, such as absorbing, reflecting and filtering with stable angular performance. The miniaturized architecture makes this design a potential candidate and can be easily integrated for radar cross section, electromagnetic interference shielding and real-time wireless applications in the Sub-6&#x00A0;GHz range. IEEE

IEEE Transactions on Electromagnetic Compatibility

Wideband Reconfigurable Multifunctional Absorber/Reflector With Bandpass/Bandstop Filtering and Band-Notch Absorption for RCS and EMI Shielding

This paper demonstrates the initial stage of developing a 1-18GHz five port frequency multiplexer. The design details of 1-6GHz and 6-10GHz bandpass filters are discussed along with their results. Modified optimum short-circuited stub technique is used for designing a 1-6GHz bandpass filter and cascading high pass filter with low pass filter is used for the design of a 6-10GHz bandpass filter. Both filters achieve a passband return loss <-15dB, passband insertion loss <2dB and stopband attenuation > 50 dB. © 2023 IEEE.

2nd International Conference on Wireless, Antenna and Microwave Symposium, WAMS 2023

Ultra broadband 1-6GHz and 6-10GHz Bandpass Filters for Frequency Multiplexer

This study demonstrates a reconfigurable wideband reflective polarizer from X to Ka-band applications. The design unitcell consists of a single PIN diode integrated metallic patch printed on a grounded dielectric substrate. When the PIN diode is reversely biased, the designed polarizer effectively converts a linearly polarized incident wave into a circular one with an effective 3 dB Axial Ratio (AR) from 8.88-9.82 GHz, 12.61-20.17 GHz and 23.67-25.08 GHz. In addition, it also performs linear-cross conversion with a minimum 90% Polarization Conversion Ratio (PCR) from 10.43-11.68 GHz and 21.27-22.78 GHz. While in the forward bias, this polarizer behaves as a perfect reflector in the lower frequency region, linear-cross conversion (21.90-23.38 GHz) and linear-circular from 19.85-21.08 GHz and 24.44-26.77 GHz. No performance degradation for oblique incidences is observed in the elevation plane up to 45°. The dual functionality is due to several surface plasmonic resonances supported by the patterns seen in the local electric field. The polarizer/reflector unitcell is very compacted (0.053λL×0.077 λL) and has a low-profile thickness of 0.047λL. Dual operation is of paramount importance in real-time applications and angular stable linear-cross, linear-circular polarizers and perfect reflectors at distinct frequency bands in a single design would be ideal in these cases. © 2023 IEEE.

Wideband Reconfigurable Linear-Linear and Linear-Circular Polarizer/Reflector Integrated With RF PIN Diodes for X/Ku/Ka-Band Applications

The dual active bridge (DAB) converter is one of the widely explored topologies in recent years due to its remarkable features, such as inherent soft-switching characteristics, galvanic isolation, and high power density. However, the conducted electromagnetic interference (EMI) analysis of the DAB converter is seldom reported. In this article, the common-mode (CM) and the differential-mode (DM) equivalent circuits of the isolated DAB converter are presented to understand the propagation mechanisms of the conducted EMI noise in the converter. In particular, the mixed-mode DM (MMDM) noise component of the DM noise is quantified for the DAB converter. Furthermore, an experimental measurement method based on an external impedance-matched circuit is proposed to quantify the DM current due to capacitive coupling between the primary and secondary windings of the transformer. The quantified MMDM noise and the DM noise through the transformer are estimated using the proposed equivalent circuits in MATLAB-Simulink and validated experimentally on a prototype DAB converter. © 2022 IEEE.

IEEE Journal of Emerging and Selected Topics in Power Electronics

Analysis of Common-Mode Noise and Mixed-Mode Differential-Mode Noise in Dual Active Bridge Converter

Dual active bridge (DAB) dc-dc converter with integrated transformer is explored in recent years due to its advantages of the low component count, high power density and high efficiency. Although the operational performance of the DAB converter is well reported, the common-mode (CM) noise with the integrated transformer is yet to be thoroughly analyzed. Hence, this paper presents a detailed analysis of the CM noise performance of the DAB converter employing integrated transformer. Moreover, the conventional CM chokes incorporated to mitigate the CM noise cause a deleterious impact on volume and power density of the converter. This paper proposes a concentric CM choke that occupies less volume compared to its equivalent conventional CM choke of the same CM impedance. The analysis and design guidelines for the proposed concentric CM choke are presented. The above-mentioned analyses of the integrated transformer and the concentric CM choke are experimentally validated on a DAB converter prototype. IEEE