Department of Electrical Engineering

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.

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IIT Palakkad

This work presents a novel antipodal endfire broadband antenna incorporating paddle like shape and a frustum shaped dielectric for microwave imaging applications. Ten paddle shaped stubs with different lengths are attached to the feed structure, and their dimensions are optimized to obtain the optimum performances. Seven frustum shaped dielectrics of same dimensions are loaded to the structure to improve the gain at higher frequencies. The proposed structure demonstrates simulated return loss of <10 dB over 3.1-14 GHz with a simulated peak gain of 12.2 dBi. © 2020 IEEE.

World University root node

Asia-Pacific Microwave Conference Proceedings, APMC

Novel UWB Antipodal Antenna with Paddle Shaped Stubs and Frustum Shaped Dielectric Loading for Microwave Imaging Applications

Conventional predictive controller selects the optimal switching state out of the available switching states by appropriate cost function optimisation. The direct application of the optimal switching state without a modulator restricts the use of carrier interleaving techniques with predictive control of parallel converters. The paper proposes a constant switching frequency predictive controller for parallel AC/DC converters with an intermediate modulation stage. The paper combines the generalised discontinuous pulse width modulation (GDPWM) technique with carrier interleaving for reducing both the switching losses of the converter and the harmonic distortion of grid currents. The parallel converter operate with separate DC loads for mitigating the flow of circulating currents. The controller guarantees good and quick dynamic response. The performance of the proposed controller-modulation is evaluated using MATLAB/SIMULINK. The paper analyses the performance of the parallel rectifier with individual converters operating at different DC load voltages and different power factor angles. © 2020 IEEE.

2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy, PESGRE 2020

Predictive Control of Parallel AC/DC Converter with Interleaved Generalised Discontinuous PWM

Conventional pulse width modulation (PWM) schemes for dual inverter fed drive synthesise the reference voltage as a switched average of minimum three voltage vectors from individual inverters. As a result, the number of transitions in the inverter increases. This paper introduces a family of PWM methods, where the reference voltage is synthesised as a switched average of only two voltage vectors from individual inverter. This leads to simultaneous clamping of two phases, thus reducing the number of switching transitions in the inverter. The concept and realisation of the proposed PWM are discussed and compared with conventional bus clamping PWM methods on the basis of inverter power loss and common mode voltage generation. The proposed PWM is experimentally validated on an open end winding induction motor drive operating with open loop control. Synchronised carrier modulation is considered for PWM generation. © 2020 IEEE.

9th IEEE International Conference on Power Electronics, Drives and Energy Systems, PEDES 2020

Clamping modulation scheme for low speed operation of dual inverter fed drives

The presence of regulated power converter in the three-phase microgrid system makes it vulnerable to interactions with the grid and causes instability. Because, the regulated converters exhibits negative impedance characteristics and acts like constant power loads (CPLs). To ensure the system stability, adaptive controller can be used in the system controller design. However, to design these adaptive controllers real-time grid impedance information is required and this is a challenging task. In this paper a Hall Binary Sequence (HBS) which is a class of pseudo random binary sequence (PRBS) is proposed for real-time impedance measurement. The HBS perturbation is computationally very effective compared to conventional multi-sine perturbation methods. Perturbation signals for impedance measurement should have low crest factor and less measurement time. The proposed HBS has low crest factor and the impedance can be measured within 3-5 perturbation cycles. To extract the impedance of the grid, the HBS is added to the inner loop currents (d-axis and q-axis) components of the energy storage system (ESS). Next, the Generalized Nyquist Stability Criteria (GNC) is applied to the return ratio matrix to check the system stability. The effectiveness of proposed impedance measurement algorithm using the HBS has been tested on three-phase microgrid system in MATLAB/Simulink environment. Simulations results are validated by conducting experiment on a 2kW laboratory test bed and results proved the robustness of the proposed impedance measurement algorithm. © 2020 IEEE.

Small signal stability analysis of three-phase microgrid in the presence of energy storage system

In this paper, a multi-port hybrid nine-arm modular multilevel converter is proposed for integration of an offshore wind farm into the HVDC subsea power transmission system feeding an offshore subsea oil and gas processing load. A detailed analysis of circulating current of the proposed converter is performed and accordingly, a control architecture based on a synchronous rotating reference frame is developed. The proposed control architecture regulates the circulating current at an optimal value in order to achieve a stable and efficient operation of the multi-port hybrid nine-arm modular multilevel converter. The proposed architecture incorporates control of phase angle difference between the source port and load port voltages, which is the key to regulate the circulating current magnitude. A system level simulation model has been developed on PLECS simulation software to demonstrate the performance of the proposed control architecture. © 2020 IEEE.

A new architecture for circulating current control in a multi-port hybrid nine-arm modular multilevel converter

2020 7th International Conference on Signal Processing and Integrated …

DSP Implementation of Hilbert Transform for Voltage Variation Tracking

This work presents a circularly polarized Fabry- Perot cavity antenna (FPCA) using a new uniplanar electro- magnetic bandgap (EBG) superstrate. Proposed EBG poses a frequency bandgap in the sub-6 GHz frequency range from 3.07-4 GHz. Unit cell has overall dimension of 0.071 λ0 × 0.071 λ0 × 0.018 λ0, where λ0 is the free space wavelength at center frequency of 3.53 GHz. A 7 × 7 EBG lattice is used as partially reflective surface (PRS) over a metamaterial based circularly polarized (CP) antenna to improve the directivity. Peak gain of the primary CP antenna is 7.51 dBic at 3.66 GHz and that of the EBG superstrate loaded FPCA is 9.67 dBic. © 2020 IEEE.

Proceedings of the 2020 International Symposium on Antennas and Propagation, APSYM 2020

EBG Superstrate Loaded Circularly Polarized Fabry-Perot Cavity Antenna at Sub-6 GHz for Satellite and 5G Cellular Communications

This paper presents a wide band six port network (SPN) with two input ports and four out ports. The designed network consists of conventional wideband Lange couplers and a Wilkinson power divider having features of out of band harmonic suppression over a wide frequency. Operation band of the SPN extends from 2.3 - 4.0 GHz covering IEEE 802.11 WLAN band at 2.4 GHz and sub-6 GHz band from 3.3 - 3.8 GHz for 5G application. A good matching at the input ports are achieved with return loss of better than 20 dB for the entire frequency range with minimum isolation between the ports is 12 dB. At frequency 3.5 GHz the output powers at the four ports are -5.56 dB, -5.47 dB, -7.07 dB, -7.16 dB with input at port-1 and the powers are -6.05 dB, -7.8 dB, -5.02 dB, -6.56 dB with input at port-2. Differential phase between two adjacent output ports are ± 90 degree. © 2020 IEEE.

IEMTRONICS 2020 - International IOT, Electronics and Mechatronics Conference, Proceedings

Compact six-port network using lange coupler for sub-6 GHz fifth generation communication

A wide-width clamped-clamped beam (CC-beam) resonator and a filter realized using mechanically-coupled resonator tanks have been extensively characterized to attain mixler (i.e., mixer-filter) functionality for a chip-scale frequency translation. Such a resonator has been driven into the nonlinear regime to explore its effect on the mixler operation as well as to obtain the best phase noise performance using the phase-feedback method. The proposed electrostatically transduced mixler operates by utilizing the local oscillator (LO) signal generated from the resonator itself, thus eliminating the need of a function generator or an external quartz crystal oscillator. This technique implemented with all the components on the same silicon substrate shows great potential for miniaturization in wireless communication while achieving 14.4 dB overall mixler loss. © 2019 Elsevier B.V.

Sensors and Actuators, A: Physical

A chip-scale frequency down-conversion realized by MEMS-based filter and local oscillator

We propose a Simulation Program with Integrated Circuit Emphasis (SPICE)-based multiphysics framework to model ferroelectric negative-capacitance-electrostatic microelectromechanical systems (MEMS) hybrid actuators. Our approach couples the nonlinear dynamics of both the ferroelectric capacitor and the MEMS actuator. Using this framework, we examine the dynamic response and the energy consumed during pull-in switching of the hybrid actuator. We predict a significant reduction in the dynamic pull-in and pull-out voltages and the energy consumed by the hybrid actuator compared with the standalone MEMS actuator. We also predict that the pull-in time of the hybrid actuator is, however, larger than that of the standalone actuator. Nevertheless, we show that one can tradeoff a small part of the reduction in actuation voltage to achieve identical pull-in times in the hybrid and standalone MEMS actuators while still consuming substantially lower energy in the former compared with the latter. Our analysis approach is compatible with standard circuit simulators and is, hence, suitable for analysis and evaluation of various heterogeneous systems consisting of hybrid MEMS actuators and other electronic devices. © 1963-2012 IEEE.