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.

Low Match-Line Voltage Swing Technique for Content Addressable Memory

Abstract: A novel pre-charge mechanism is presented to design an energy efficient content addressable memory (CAM) with improved search performance. This scheme reduces the match-line (ML) power dissipation by lowering the loading capacitance and ML voltage swing. A $\mathbf{256}\times \mathbf{64-bit}$ NOR-based CAM has been designed with the incorporation of this scheme with predictive 45-nm CMOS technology and post layout simulations are carried out in SPECTRE at 1 V supply. This scheme reduces the energy dissipation by 38% compared to the traditional precharging with 4.7% improvement in search speed.

Frequency control of autonomous hybrid power system using smart controllable load

Abstract: In recent years, penetration of renewable energy technologies in electrical power systems have increased the system complexity and therefore require efficient controlling methods to ensure stable operation of the whole system. In present study, the frequency control of autonomous hybrid power system consisting of various generators such as wind turbine generator, diesel engine generator, fuel cell and solar photovoltaic is investigated in integration with aqua electrolyzer and smart controllable water heater. The intermittent nature of wind and solar power may cause a serious problem of frequency fluctuation. Therefore, a new robust PID controller with filtering technique (PIDF) has been designed for the proposed system to minimize the frequency deviation to zero. Proposed controller is provided with derivative filter to improve the performance when there is noise or random error in the measured process variables. Nature-inspired firefly algorithm (FA) based optimization is employed to search for optimal controller parameters and the corresponding dynamic performance are compared with conventional PI controller. Initially investigation has been carried out considering 1% step load perturbation (SLP) and then against random load pattern. Furthermore, performance of proposed controller against random variation of wind input power has been tested. Critical investigation reveal that firefly optimized PIDF controller is far superior to conventional PI controller in terms of settling time, reduced overshoots, undershoots and oscillation.

A low-cost microcontroller-based prototype design for power factor improvement in transmission line using thyristor switched capacitor scheme

Abstract: When the reactive power demand increases it leads to poor power factor and thus increasing the losses more. So reducing losses as well as for improvement of power factor, a low cost arrangement is presented in this paper which utilizes static VAR compensation (SVC) scheme. SVC consists of two structures i.e., thyristor switched capacitor (TSC) and thyristor switched reactor (TCR). TSC scheme is employed here which is a cost effective method because it doesn't generate any harmonics and thus eliminates the filtering requirement. Fast acting thyristors, resistive-inductive loads, and ATmega 16 microcontroller are taken for designing the circuit. The microcontroller drives the bidirectional thyristor present in the TSC by generating required pulses. The prototype is developed using Proteus software environment and results are verified with experimental design which shows improvement in power factor. Both simulation and hardware results are validated under different loading conditions.

Performance Analysis of Twin-Rotor Axial Flux Permanent Magnet Synchronous Motor for In-Wheel Electric Vehicle Applications with Sensorless Optimized Vector Control Strategy

Abstract: The operating characteristics of double rotor axial flux permanent magnet synchronous motor with sensorless optimized vector control strategy is analysed in this paper for in-wheel electric vehicle applications. Double rotor single stator configuration of the axial flux motor designed using 3D finite element analysis based on a standard electric bicycle motor specifications is used for the analysis. Sensorless vector control strategy based on higher order sliding mode observer with super twisting algorithm is implemented for the performance analysis of the motor. Adoption of this method aids in the elimination of mechanical sensors from the system resulting in reduction of size and cost of the overall system which is desirable for electric vehicle application. The gains of proportional-integral speed controller in vector control strategy are optimized to reduce the speed as well as the torque ripples in the performance characteristics using particle swarm optimization algorithm. Simulation study of the sensorless motor drive system formulated on higher order sliding mode observer shows good motor performance through accurate rotor position and speed estimation which can be inferred from results. Hence the drive system is more suitable for hub motor electric drive applications.