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.

Performance Analysis of N-CAM, P-CAM and TG-CAM Using 45-nm Technology

Abstract: Content addressable memory (CAM) is widely used in many applications, wherever we need fast memory access CAM provides a provision. CAM is faster due to the arrangement of core cells that allows parallel access, it searches total memory array in single clock cycle. CAM plays a crucial role in network applications because of its parallel access. In this paper, we explored and described about CAM architectures based on N-type, P-type and TG-type comparison circuitry. For faster memory search, we used a latch-type match-line (ML) sensing scheme. Search operations and results of the CAM designs have been verified using a 45-nm CMOS process at 27°C with 1 V supply in SPECTRE simulator. Based on the post-layout results of 32×32-bit arrays, the P-CAM provides the best performance comparatively.

Novel Reduced Switch Multilevel Inverter Suitable for Photovoltaic Application with Selective Harmonic Elimination Control

Abstract: Design and application of optimized multilevel inverter (MLI) with reduced components count in different applications is the present focus among the Power electronics research community. This paper presents a novel reduced switch level doubling (RSLD) MLI. Due to the inclusion of a level doubling circuit, proposed MLI produces 4n+1 voltage levels instead of 2n+1 at the output. The design consideration is justified with performance comparison among few recently developed MLI topologies in view of switch count, source count, standing voltage, and loss. Selective harmonic elimination (SHE) technique is used to control the proposed thirteen-level RSLD MLI by determining optimal switching angles. Moreover, the objective evaluation and harmonic minimization in MLI are delineated through SHE-PWM control. MATLAB/SIMULINK platform is used for simulation of the proposed MLI under a dynamic change in modulation index as well as varying load conditions. Furthermore theoretical and simulated findings are validated experimentally by similar tests on a developed prototype of the proposed thirteen-level MLI.

Numerical Investigation to Study Effect of Number of Blade in Propeller Loading with Composite Material

Abstract: In the advancement phase of science and technology, it becomes an important issue to opt for non-traditional resources to save fuel or energy. Due to increasing trend in oil price, restrictions on air pollutions, and additionally, to have more financial gains, researchers are concentrating on replacing conventional material with some other substitute material. In this paper, conventional marine propeller material is replaced by glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP) to investigate their effect on the blade loadings with respect to the number of blades. Here, four propellers are considered with one, two, three and four number of propeller blades for numerical investigation, and the obtained results are analysed. It may be noted here that the number of propeller blades is limited up to four keeping in mind about the increase in manufacturing cost and additionally, the blockage effect due to increased number of blades. It has been noticed that stress, strain and deflection produced are less in a GFRP propeller in comparison to those obtained for a CFRP propeller, and it gradually decreases with the increase of number of propeller blades.

Modelling and Control of the Hydraulically Actuated Horizontal Axis Wind Turbine Pitch System

Abstract: The advantages of renewable energy sources are available freely in nature, inexhaustible, produce either no or little pollution and low gestation period. Among all renewable energy sources, wind energy has become one of the leading resources for power production in the world as well as in the India. According to WWEA, the wind turbine installation capacity in the world has been reached over 539.291GW by the end of 2017. The entire wind power installed capacity by the end of 2017 covers more than 5% of global demand of electricity. In India, the present wind power installation capacity on October, 2017 was over 32.7GW and wind energy contribution is 55% of the total renewable energy capacity in the country. Inspite of having sharp growth rate in wind in India, only a fraction of wind energy has been tapped until now out of 302 GW wind potential which is available above 100 m height on shore. Practical horizontal axis wind turbine converts kinetic energy in the wind into useful energy by using airfoil blades. Blade element momentum (BEM) theory becomes very popular due to its simplicity in mathematical calculation as well as accuracy. Hydraulic pitch actuation system has certain advantages due to its versatility, ability to produce constant force and torque irrespective of the disturbances outside of the system, ease and accuracy of control, simplicity, safety and economy. In the present study a semi rotary actuator has been utilized for turbine pitch actuation. In order to extract maximum power from available wind, fractional order PID controller (FOPID) has been developed for pitch control of wind turbine rotor blade. The performances of PID as well as FOPID controller have been compared with available wind data. The performance of FOPID controller was satisfactory compare to PID controller.