National Institute of Technology, Meghalaya

About: National Institute of Technology, Meghalaya is a education organization based out in Shillong, India. It is known for research contribution in the topics: Control theory & Electric power system. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

OpenFlow-Based Scalable Routing With Hybrid Addressing in Data Center Networks

Abstract: In this letter, we propose an OpenFlow (OF)-based SCAlable Routing strategy (OSCAR) for modular data center networks (DCN) using a hybrid addressing mechanism. Each module in the DCN constitutes a segment in the network. Inter-segment routing is performed using virtual MAC (VMAC) ids assigned to the segments and intra-segment routing is done using IP addresses. OF provides central control over the network but it suffers from limited scalability in DCNs due to high control traffic. In OSCAR, the control traffic is minimized to achieve high scalability and flexibility in DCN routing.

Mechanical Contact-Less Computational Speed Sensing Approach of PWM Operated PMDC Brushed Motor: A Slotting-Effect and Commutation Phenomenon Incorporated Semi-Analytical Dynamic Model-Based Approach

Abstract: This brief proposes a mechanical contact-less speed sensing approach for a pulse width modulation (PWM) operated permanent-magnet direct current (PMDC) brushed motor. A recently reported semi-analytical dynamic model which incorporates the space-domain effects, namely slotting-effect and commutation phenomenon, has been taken into consideration to apply the proposed computational speed sensing approach. This speed sensing approach is basically an indirect estimation process and discrete in manner. The proposed method is efficiently applicable at higher range of speed. Zones of estimations with varying load torque and PWM duty cycle are represented with appropriate responses. A simulation of the proposed estimation method is applied over the dynamic semi-analytical model of 24 V, 12 teeth-slots, 100 W PMDC brushed motor, and various responses are represented in this brief.

Surface characteristics and erosion phenomena in WEDM of alumina composites

Abstract: Reinforcing the ceramic materials with a conducting filler allows the net electrical properties to increase. This makes the composites machinable by electrical discharge process. Present work identifies the influence of multi-walled carbon nanotubes (MWCNT) as conducting fillers toward the machined surface profile. Alumina composites with 5 and 10 vol. % MWCNTs are fabricated and machined by wire electrical discharge machining process. The spalling effect is found to be more dominant at lower MWCNT concentrations in the composites. Cracks, porosity, and oxidization of the surface materials are the main defects observed during the machining process. Also, a more intense cracks and porous behavior is observed at lower concentration of MWCNT (5 vol. %). A closer analysis of machined surface edges yielded some phenomena of mechanical erosion and chipping due to physical contact. This situation is brought forward by low electrical conductivity and high brittleness of the composites. The Energy Dispersi...

Comparative Analysis of Adaptive PI Controller for Current Harmonic Mitigation

Abstract: The proposed technique employs Shunt Active Power Filter (SAPF) and controller optimization technique through Ant Colony Optimization (ACO) algorithm to reduce current harmonics that appeared in the presence of non-linear loads. Non-linear load devices such as Adjustable Speed Drive (ASD), furnaces, modern power Electronics etc. cause unbound harmonics during their operation. To mitigate the harmonic components, Synchronous Reference Frame Theory (SRFT) is introduced in the controlled circuit to generate gate pulses to the SAPF, and consequently inject equal and opposite harmonics magnitude to the system. The controller parameters are optimized using the ACO algorithm. The comparison analysis shows better performance compared with existing algorithms such as conventional PI controller, Genetic Algorithm (GA), and Eagle Perching (EP).