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

Low complexity distributed active noise control (ANC) systems are highly demanded for industrial applications. The ANC systems based on centralized multichannel filtered s least mean square (FsLMS) and Chebyshev-functional link artificial neural network (C-FLANN) FsLMS have shown promising results in cancellation of active noise. In distributed ANC scenario, there is a possibility in reducing the complexity by incorporating constraints on secondary paths. In this paper, we present improved distributed C-FLANN FsLMS algorithm for active control of nonlinear noise process. Based upon simulation study, it has been proven that the computational complexity can be significantly reduced by considering the error introduced at the target node due to the neighboring nodes in addition with self error of that node. Without significantly degrading the noise cancellation performance, the improved constrained distributed C-FLANN FsLMS scheme can achieve complexity improvement of 33.86% for multiplications and 22.58% for additions as compared with multichannel FsLMS considering 4 nodes. © 2016 IEEE.

World University root node

2016 IEEE Region 10 Conference (TENCON)

Low complexity distributed active noise control using secondary path constraints

This paper presents a new control scheme for a single-phase PWM rectifier with Auxiliary Current Injection Circuit (ACIC) to improve the load transient response and DC bus voltage controller bandwidth. The PWM rectifier and ACIC are controlled to mitigate the 2nd harmonic ripple in the DC bus under steady-state as well as the peak undershoot and overshoot during load transients. Analytical equations governing the operation of the single phase PWM rectifier with proposed ACIC controller are derived and presented. The proposed controller is designed and simulated using MATLAB Simulink and implemented on a 100 W test setup. The simulation and experimental results are presented to validate the performance of proposed controller. © 2016 IEEE.

Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC

A new control scheme to improve load transient response of single phase PWM rectifier with Auxiliary Current Injection Circuit

In this paper, a new inverter topology is proposed for generating a multilevel dodecagonal voltage space vector structure for open-end winding induction motor (IM) using a single dc source. Dodecagonal voltage space vector structure eliminates fifth- and seventh-order harmonic voltages from phase voltage output and hence eliminates the fifth- and seventh-order harmonic currents through the motor leading to removal of the dominant sixth-order torque ripple generation in the motor over the entire modulation range. Multilevel space vector structure generates output voltage with better THD and low dv/dt. In the proposed topology, two three-level inverters drive an open-end winding IM, one inverter from each side. DC-link of primary inverter is from a dc source which delivers the entire active power, whereas the secondary inverter dc-link is maintained by a capacitor, which is self balanced during the inverter operation. The PWM scheme implemented ensures low switching frequency for primary inverter. Secondary inverter operates at a small dc-link voltage. Hence, switching losses are small for both primary and secondary inverters. Experimental results show the elimination of fifth- and seventh-order harmonic voltages over the entire modulation range, validating effectiveness of the proposed multilevel inverter scheme.

IEEE Transactions on Industrial Electronics

Multilevel Dodecagonal Voltage Space Vector Structure Generation for Open-End Winding im Using a Single DC Source

A fifth and seventh order harmonic elimination scheme for IM drive with a multilevel dodecagonal voltage space vector structure using a single DC source is proposed in this work. Single DC source requirement makes four quadrant operation of the drive system simpler compared to the multilevel do-decagonal structures presented in literatures before. The space vector structure consists of six concentric dodecagons, combining the advantages of multilevel operation as well as dodecagonal structure. The topology consists of a three-level flying capacitor (FC) inverter cascaded with a capacitor fed H-bridge (CHB) inverter. The FC inverter operating at high voltage switches in a quasi-square wave mode whereas the CHB inverter operating at a lower voltage switches at high frequency to remove the harmonics generated by the FC inverter. Switching losses are low, both in the FC and CHB inverters. Experiment results for open-loop V/f operation are included in this paper showing the effectiveness of the drive scheme.

2016 18th European Conference on Power Electronics and Applications, EPE 2016 ECCE Europe

A multilevel inverter fed im drive with dodecagonal voltage space vector structure using a single DC source with linear modulation range near to base speed

In rate-adaptive orthogonal frequency division multiplexing (OFDM) systems, limited feedback schemes are essential to reduce the number of subchannels for which the channel state information is fed back by the users. For the practically important best-M scheme, in which each user feeds back only its M strongest subchannels and their indices to the base station (BS), we derive a throughput-optimal rate adaptation policy that enables the BS to assign rates to the subchannels of every user. We present it in closed-form for the widely used exponential correlation model. The novelty of the policy lies in its exploitation of the structure of the information fed back by the best-M scheme and the correlation among subchannel gains. We also present a near-optimal, lower computational complexity approach. In effect, our approach facilitates rate adaptation and scheduling by the BS even on subchannels that are not fed back by a user due to feedback constraints. For various schedulers, we show that it improves the downlink throughput compared to several conventional approaches, without requiring any additional feedback. © 2016 IEEE.

2016 IEEE International Conference on Communications, ICC 2016

Throughput-optimal rate adaptation for best-M feedback in OFDM systems

Time-variations in wireless channels affect opportunistic selection in a multi-node wireless system in two ways. First, the selected node can become sub-optimal by the time data transmission commences. Second, the channel changes during data transmission. We develop a comprehensive and tractable analytical framework that accurately accounts for both these effects. It differs from the extensive existing literature that primarily focuses on time-variations until the data transmission starts. We first develop a novel concept of a time-invariant effective signal-to-noise ratio (TIESNR), which tractably and accurately captures the time-variations during the data transmission phase with partial channel state information available at the receiver. Thereafter, we model the joint distribution of the signal-to-noise ratio at the time of selection and TIESNR during the data transmission and analyze the average packet error rate (PER). Extensive numerical results verify the accuracy of each step of our approach and show that ignoring the correlated time-variations during the data transmission phase can significantly underestimate the average PER. © 2016 IEEE.

A tractable analytical framework for evaluating opportunistic selection in time-varying channels

This paper presents tracking control laws for two different objectives of a nonholonomic system - a spherical robot - using a geometric approach. The first control law addresses orientation tracking using a modified trace potential function. The second law addresses contact position tracking using a right transport map for the angular velocity error. A special case of this is position and reduced orientation stabilization. Both control laws are coordinate free. The performance of the feedback control laws are demonstrated through simulations. © 2016

IFAC-PapersOnLine

Geometric tracking control for a nonholonomic system: a spherical robot

For real-Time sparse systems identification applications, Proportionate-Type Least Mean Square (Pt-LMS) algorithms are often preferred to their normalized counterparts (Pt- NLMS) due to lower computational complexity of the former algorithms. In this paper, we present the convergence analysis of Pt-LMS algorithms. Without any assumptions on input, both first and second order convergence analysis are carried out and new convergence bounds are obtained. In particular, it establishes the universality of the steady-state mean square deviation. Detailed simulation results are presented to validate the analytical results.

Signal Processing - Algorithms, Architectures, Arrangements, and Applications Conference Proceedings, SPA

Performance analysis of proportionate-Type LMS algorithms

This paper focuses on Voltage Fed Dual Active Bridge (VF-DAB) bidirectional DC-DC converter modules connected Input Parallel and Output Parallel (IPOP) configuration. Modularity or parallel operation of the bidirectional DC-DC converters for energy storage application is not just an economic solution for increasing the power transfer capability, but also provides several advantages such as redundancy, reduced design cost and hot swap feature of faulty module. In this paper, an interleaved VF-DAB with phase-shedding operation at light loads are proposed for interfacing energy storage devices to a common DC bus. A modification in the conventional active current sharing technique for parallel operated converters is proposed to implement phase shedding and phase adding operation. A 12 kW interleaved IPOP based DAB converter is proposed and simulated to validate the claims. © 2015 IEEE.

INTELEC, International Telecommunications Energy Conference (Proceedings)

A new phase shedding and phase adding control scheme for interleaved DAB converter operating in IPOP configuration

This paper presents a radio frequency micro-electromechanical system (RF MEMS) based 3-bit phase shifter using MEMS single-pole-eight-throw (SP8T) switches. Devices are fabricated on 635 μm alumina substrate utilizing on the coplanar waveguide (CPW) transmission line. Single switch dimensions are 0.14 × 0.23 mm2 which is much smaller than Si-on-insulator switches. The symmetric and compact SP8T switch is the primary building block of the 3-bit phase shifter. The SP8T switch results in isolation levels of 31-15 dB, return loss of 33-18 dB and insertion loss of 0.6-1.9 dB, respectively, at 26-40 GHz. Later, two SP8T switches are connected back to back to develop the 3-bit phase shifter using different delay lines at 35 GHz. Finally, the phase shifter provides average return loss of better than 14 dB and average insertion loss of 4.4 dB over the 34.75-35.25 GHz. Measured average phase error is less than 0.98° at 35 GHz. The total area of the fabricated 3-bit phase shifter is 5.95 mm2. SP8T switches are capable of handling 0.1-1 W of power up to 100 million cycles which is sufficient power handling capability for wireless communication systems. Reliability of the phase shifter is extensively characterized with different incident RF powers at room temperature (25°C) and discussed in detail. To the best of the authors' knowledge, this is the first reported MEMS 3-bit phase shifter in the literature that has used a minimum number of switching elements per phase state. © 2016 IOP Publishing Ltd.