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 & Computer science. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

Reduced Switch Single DC Source Cascaded H-bridge Multilevel Inverter based DSTATCOM

Abstract: The application of multilevel inverters (MLIs) for the realization of Distribution Static Compensator (DSTATCOM) overcomes the requirement of higher power rating of switches. However, the high component count and multiple DC-link capacitors in conventional MLIs make the inverter design complicated. These inverters also require additional controls and circuits for DC-link capacitor voltage balancing for its satisfactory multilevel output. This paper proposes a reduced switch single DC source cascaded H-bridge multilevel inverter (RSDCHBMLI) for DSTATCOM operation. The RSDCHBMLI uses a single DC-link capacitor and hence eliminates the problem of capacitor voltage balancing. The topology also leads to reduction in component count along with inherent isolation. FCS-MPC current control is implemented to perform load compensation in presence of feeder impedance along with maintaining sinusoidal voltages at the point of common coupling (PCC). This paper also implements a current based DC-bus voltage controller which allows easier calculation of the controller gain parameters. The performance of the current based controller is found to be better than the conventional DC-bus controllers under the test conditions and results are presented for a 11-kV distribution system simulated in PSCAD/EMTDC environment.

Design and Implementation of Threshold Logic Functions Using Memristors

Abstract: In this paper, a new design to implement programmable Threshold Logic Gate (TLG) using memristors as weights combined with CMOS circuits for threshold control and comparison has been reported. In this design it is possible to program both weights and threshold of the gate that gives greater flexibility in implementing logic functions with minimum gate count. The operation of the gate has been experimentally verified through simulation by implementing some linear threshold logic functions.

PSO Method for Fitting Analytic Potential Energy Functions. Application to I–(H2O)

Abstract: In this work a particle swarm optimization (PSO) algorithm was used to fit an analytic potential energy function to I–(H2O) intermolecular potential energy curves calculated with DFT/B97-1 theory. The analytic function is a sum of two-body terms, each written as a generalized sum of Buckingham and Lennard-Jones terms with only six parameters. Two models were used to describe the two-body terms between I– and H2O: a three-site model H2O and a four-site model including a ghost atom. The fits are compared with those obtained with a genetic/nonlinear least-squares algorithm. The ghost atom model significantly improves the fitting accuracy for both algorithms. The PSO fits are significantly more accurate and much less time-consuming than those obtained with the genetic/nonlinear least-squares algorithm. Eight I–---H2O potential energy curves, fit with the PSO algorithm for the three- and four-site models, have RMSE of 1.37 and 0.22 kcal/mol and compute times of ∼20 and ∼68 min, respectively. The PSO fit for th...

Modelling and simulation-based performance study of a transformerless single-stage grid-connected photovoltaic system in Indian ambient conditions

Abstract: This paper presents a transformerless single-stage full-bridge inverter for a grid-connected photovoltaic system (GCPVS) and its performances based on power loss, efficiency, and total harmonic distortion for the conditions: (a) seasonal variations of inputs in the photovoltaic (PV) system, (b) variation of grid voltage, and (c) variation of carrier frequency and Modulation Index of sinusoidal pulse-width modulation of the inverter. A typical 2.8 kWp, 368 V nominal PV array-based GCPVS is modelled and simulated to evaluate proper load matching in Indian ambient and grid conditions prior to practical implementation. Detailed analyses on system powers, power losses, efficiency, and harmonic distortions as well as selection of parameters for the simulation model are presented. The impacts of penetrating PV power into electric grid are investigated in order to predict the possible unwanted consequences.

Monitoring and Control of MultiBus Microgrid System Using FPGA Platform

Abstract: This paper proposes a complete designing and developing the current control technique for IEEE 9 bus generation system. It describes the design of a control strategy known as decoupled controller which contains a pre-compensator and observer are added with Linear Quadratic Regulator (LQR). The proposed controller controls active and reactive power and Pulse Width Modulation (PWM) for generation of appropriate switching signals are employed in the performance analysis of individual DG unit to acquiesce the operation of Multibus Microgrid system. The effectiveness of the suggested controller was justified experimentally by using Xilinx System Generator (XSG) via MATLAB/Simulink along with the consideration of the Multibus Microgrid system under grid connected and islanded mode operations.