Faculty Publications
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Publications by NITK Faculty
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Item Three-phase three-level boost-type front-end PFC rectifier for improving power quality at input AC mains of telecom loads(Korean Institute of Power Electronics editor@kipe.or.kr, 2018) P, P.; Kalpana, R.; Singh, B.A three-phase, three-switch, and three-level boost-type PWM rectifier (Vienna rectifier) is proposed as an active front-end power factor correction (PFC) rectifier for telecom loads. The proposed active front-end PFC rectifier system is modeled by the switching cycle average model. The relation between duty ratios and DC link capacitor voltages is derived in terms of the system input currents. Furthermore, the feasible switching states are identified and applied to the proposed system to reduce the switching stress and DC ripples. A detailed equivalent circuit analysis of the proposed front-end PFC rectifier is conducted, and its performance is verified through simulations in MATLAB. Simulation results are verified using an experimental setup of an active front-end PFC rectifier that was developed in the laboratory. Simulation and experimental results demonstrate the improved power quality parameters that are in accordance with the IEEE and IEC standards. © 2018, Korean Institute of Power Electronics. All rights reserved.Item Inclusive Design and Development of Front-End Multiphase Rectifier with Reduced Magnetic Rating and Improved Efficiency(Institute of Electrical and Electronics Engineers Inc., 2020) P, P.; Kalpana, R.; Singh, B.This article proposes a 20-pulse asymmetric multiphase converter (AMPC) suitable for medium-and high-power applications. Unlike the other state-of-the-art 20-pulse delta-connected autotransformers, the proposed delta-connected AMPC has an ability to reduce input harmonics, maintains high efficiency, and requires a magnetic rating of only 30.12% of the nominal load; thereby, a significant reduction in space, weight, and overall cost required is the salient features of the proposed AMPC. A detailed power quality performance analysis and an efficiency calculation are discussed. First, the proposed AMPC configuration is simulated in MATLAB/Simulink environment for evaluating its viability under different loading conditions, and the results are illustrated. A detailed comparison of the proposed AMPC configuration with other multipulse transformers is included, which confirms the merits of the proposed system. Also, a prototype is developed, and the experimental measurements obtained are presented to validate the feasibility and operability of the proposed AMPC. The proposed AMPC offers a total harmonic distortion of 3.7% and can operate at near-unity power factor complying with the IEEE and IEC standards. © 2013 IEEE.Item New Bit Pattern Based IPv6 Address Compression Techniques for 6LoWPAN Header Compression(Institute of Electrical and Electronics Engineers Inc., 2022) Geetha, V.; Bhat, A.; Thanmayee, S.Things in the world can be connected to the Internet through various technologies such as Wi-Fi, Bluetooth, IEEE 802.15.4 etc. Among all IPv6 over IEEE 802.15.4 looks promising for outdoor environments for connecting a very large number of resource constrained sensor nodes. 6LoWPAN is an adaptation layer to support IPv6 over IEEE 802.15.4 to overcome the challenge of the physical layer with respect to the limitation of 127 bytes of payload. 6LoWPAN supports header compression as one of its functions to reduce the number of bits in header by using compression techniques. Static Context Header Compression (SCHC) provides RuleID based header compression. This paper proposes further compression of address bits based on compressing leading zeros in IPv6 addresses. The proposed work is analysed with respect to Header compression HC1 of 6LoWPAN and SCHC techniques. The simulation results show compression of address bits are 10% to 40% more compared to traditional address compression of the 6LoWPAN address compression when continuous zeroes are present in the address. The compression of address bits provides sufficient space for sending data payload in one frame during communication. © 2013 IEEE.Item An integrated PMU architecture for power system applications(De Gruyter Open Ltd, 2022) Aalam, M.K.; Shubhanga, K.N.Time synchronized phasors obtained using Phasor Measurement Units (PMU) spread across wide areas have revolutionized power system monitoring and control. These synchronized measurements must be accurate and fast in order to comply with the latest IEEE standards for synchrophasor measurements. The speed at which a PMU provides an output depends on the group delay associated with that PMU and the permissible group delay in-turn decides the utility of a PMU for either control or measurement application. Based on the group delay compensation techniques, in the literature, two individual types of PMUs, such as causal and non-causal PMUs have been introduced. This paper presents an approach where both causal and non-causal PMUs are combined in an integrated PMU architecture. This method not only illustrates the group delay performance of two PMUs in a single module, but also can be used for multiple functions. In this environment several PMU algorithms have been compared with respect to their group delays and their effect on the response time. Application of the integrated PMU architecture to a four-machine 10-bus power system has been demonstrated using a six-input PMU with three-phase voltage and current signals as inputs. Different causal compensation schemes are introduced due to the availability of voltage and current-based frequency and ROCOF signals. Impact of these compensation schemes on PMU accuracy is evaluated through the Total Vector Error (TVE) index. The influence of these compensation schemes on measurements like power and impedance is also investigated. Finally, outputs from the integrated PMU architecture are fed into a Power System Stabilizer (PSS) to control the small-signal stability performance of a power system during dynamic conditions. © 2021 Walter de Gruyter GmbH, Berlin/Boston.Item Hop count, ETX and energy selection-based objective function for image data transmission over 6LoWPAN in Internet of Things(Inderscience Publishers, 2024) Bhat, A.; Geetha, V.Internet of Things (IoT) is a technology which connects millions of things to the internet for collecting data and controlling things. 6LoWPAN is designed with the idea to connect resource-constrained IoT devices. The current design of 6LoWPAN poses several challenges to support multimedia IoT devices such as cameras and audio recorders. This paper addresses one of the challenges in the area of parent selection with a new hop count, ETX and energy selection-based Objective Function (OF) for multimedia data traffic. The performance of the proposed OF is compared with existing OF with respect to packet delivery ratio, control traffic overhead, energy consumption and latency running simulations on different topologies in Cooja. The results of the simulations indicate the proposed OF performs better than existing methods in all the areas measured. Experimental results mention that the proposed HEE-OF improves PDR, overhead and energy parameters by 4%, 6% and 3%, respectively. © 2024 Inderscience Enterprises Ltd.Item Multi-Agent-Based Coordinated Voltage Regulation Technique in an Unbalanced Distribution System(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Tangi, S.; Gaonkar, D.N.; Nuvvula, R.S.S.; Ali, A.; Riyaz Ahammed, S.R.Unbalanced active distribution networks must be carefully analyzed to minimize undesirable implications from internal unbalances and the incorporation of intermittent sources, such as DG (Distributed Generation). A coordinated voltage regulation mechanism is being created employing a MAS (Multi-Agent System) control structure to solve the difficulties mentioned earlier. The proposed technique increases coordination between DGs and Shunt capacitors (SCs) to optimize the voltage profile and reduce overall power losses, along with voltage and current unbalanced factors in the proposed unbalanced 3-phase radial distribution network. To ensure improved real-time monitoring, PMUs (Phasor Measurement Units) measure the state parameters of the above-regulated distribution network in realtime. Because it does not necessitate the placement of PMUs at all nodes for total network observability, it is a cost-effective technique for estimating network state. The IEEE standard, a 25-bus unbalanced 3-phase distribution network feeder, is used to assess the viability of the recommended technique. MATLAB R2024a programming is used to simulate the case studies. © 2025 by the authors.Item CAR-BRAINet: Sub-6 GHz aided spatial adaptive beam prediction with multi head attention for heterogeneous vehicular networks(Institute of Physics, 2025) Menon, A.G.; Krishnan, P.; Lal, S.Heterogeneous Vehicular Networks (HetVNets) play a crucial role by integrating different communication technologies, such as sub-6 GHz, mm-wave, and DSRC, to meet the diverse connectivity requirements of 5G/B5G vehicular networks. HetVNet helps address humongous user demands, but maintaining a steady connection in highly mobile, real-world conditions remains challenging. Though ample studies have been conducted on beam prediction models, a dedicated solution for HetVNets has been sparsely explored. Hence, developing a reliable beam prediction model, specifically for HetVNets, is necessary. This paper introduces a lightweight deep learning-based model termed ‘CAR-BRAINet’, which consists of convolutional neural networks with a powerful multi-head attention (MHA) mechanism. Existing literature on beam prediction is primarily studied under a limited, idealised vehicular scenario, often overlooking the real-time complexities and intricacies of vehicular networks. Therefore, this study aims to mimic the complexities of a real-time driving scenario by incorporating key factors, such as prominent MAC protocols (3GPP-C-V2X and IEEE 802.11BD), the effect of Doppler shifts under high velocity and varying distance, and SNR levels, into three high-quality dynamic data sets for urban, rural, and highway vehicular networks. CAR-BRAINet achieves a steady improvement of 11.6467% in spectral efficiency, with a 93.1638% lighter architecture compared to existing methods, resulting in a 94.7103% reduction in prediction time. Therefore, demonstrating a precise beam prediction across all vehicular scenarios, with minimal beam overhead. Thus, this study justifies the effectiveness of CAR-BRAINet in complex HetVNets, offering promising performance without relying on mobile users’ location, angle, and antenna dimensions, thereby reducing redundant sensor latency. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.