Showing 7 results for Efficiency
H. Jamali Rad, B. Abolhassani, M. Abdizadeh,
Volume 8, Issue 3 (9-2012)
Abstract
In this paper, we study the problem of power efficient tracking interval management for distributed target tracking wireless sensor networks (WSNs). We first analyze the performance of a distributed target tracking network with one moving object, using a quantitative mathematical analysis. We show that previously proposed algorithms are efficient only for constant average velocity objects however, they do not ensure an optimal performance for moving objects with acceleration. Towards an optimal performance, first, we derive a mathematical equation for the estimation of the minimal achievable power consumption by an optimal adaptive tracking interval management algorithm. This can be used as a benchmark for energy efficiency of these adaptive algorithms. Second, we describe our recently proposed energy efficient blind adaptive time interval management algorithm called Adaptive Hill Climbing (AHC) in more detail and explain how it tries to get closer to the derived optimal performance. Finally, we provide a comprehensive performance evaluation for the recent similar adaptive time interval management algorithms using computer simulations. The simulation results show that using the AHC algorithm, the network has a very good performance with the added advantage of getting 9 % closer to the calculated minimal achievable power consumption compared with that of the best previously proposed energy efficient adaptive time interval management algorithm.
T. Baldawi, A. Abuelhaija,
Volume 15, Issue 4 (12-2019)
Abstract
A model of a low noise high quantum efficiency n+np Germanium Photodiode utilizing ion implantation technique and subsequent drive-in diffusion in the n layer is presented. Numerical analysis is used to study the influence of junction depth and bulk concentration on the electric field profile and quantum efficiency. The performance of the device is theoretically treated especially at the wave-length region 1.55μm where the Silica optical fiber has minimum attenuation loss. It has been found that at this wave-length and for the optimum device design the quantum efficiency approaches about 90%.
H. Shayeghi, S. Pourjafar, F. Sedaghati,
Volume 17, Issue 2 (6-2021)
Abstract
This work introduces a new non-isolated buck-boost DC-DC converter. Interleaved configuration of the suggested structure increases the voltage conversion ratio. The voltage rate of the suggested converter can be stepped-up and stepped down for lower values of duty-cycle, which causes to decrease in the conduction losses of the system. The voltage conversion ratio of the recommended structure is provided with low maximum voltage throughout the semiconductor elements. Additionally, utilizing only one power switch facilitates converter control. Using a single power MOSFET with small conducting resistance, RDS-ON, increases the overall efficiency of the recommended topology. To verify the performance of the presented converter, technical description, mathematical survey, and comparison investigation with similar structures are provided in the literature. Finally, a laboratory scheme with a 100W load power rate at 50 kHz switching frequency is carried out to demonstrate the effectiveness of the proposed converter.
S. K. Gudey, S. Andavarapu,
Volume 17, Issue 3 (9-2021)
Abstract
A three-phase dual-port T-type asymmetrical multilevel inverter (ASMLI) using two sources, solar forming the high voltage level and the battery forming the low voltage level, is considered for grid interconnection. A vertical shifted SPWM is used for the ASMLI circuit. A transformerless system for grid interconnection is achieved for a 100-kW power range. A well-designed boost converter and a Buck/Boost converter is used on the front side of the inverter. Design of battery charge controller and its controlling logic are done and its SOC is found to be efficient during charging and discharging conditions. A closed-loop control using PQ theory is implemented for obtaining power balance at 0.7 modulation index. The THD of the current harmonics in the system is observed to be 0.01% and voltage harmonics is 0.029% which are well within the permissible limits of IEEE-519 standard. The power balance is found to be good between the inverter, load, and the grid during load disconnection for a period of 0.15s. A comparison of THD’s, voltage, current stresses on the switches, and conduction losses is also presented for a single-phase system with respect to a two-level inverter which shows improved efficiency and low THD. Hence this system can be proposed for use in grid interconnection with renewable energy sources.
S. Saeedinia, M. A. Shamsi-Nejad, H. Eliasi,
Volume 18, Issue 2 (6-2022)
Abstract
This paper proposes a grid-connected single-phase micro-inverter (MI) with a rated power of 300 W and an appropriate control strategy for photovoltaic (PV) systems. The proposed MI is designed based on a two-stage topology. The first stage consists of a SEPIC DC-DC converter with high voltage gain to step up the voltage of the PV panel and harness the maximum power, while the second stage includes a full-bridge DC-AC converter. The advantages of the proposed MI are the use of fewer components to provide suitable output voltage level for connection to a single-phase grid, continuous input current, limited voltage stress on the switch, high efficiency, long operational lifetime, and high reliability. Lower input current ripple and the presence of film capacitors in the power decoupling circuit increase the lifetime and reliability of the proposed MI. In the proposed MI, the active power decoupling circuit, which is normally used in a typical single-stage SEPIC-based MI, is eliminated to achieve both a long lifetime and high efficiency. The operating principles of the proposed MI are analyzed under different conditions. The results of design and simulation confirm the advantages and proper performance of the proposed MI.
M. Soruri, S. M. Razavi, M. Forouzanfar,
Volume 18, Issue 3 (9-2022)
Abstract
Power amplifier is one of the main components in the RF transmitters. It must provide various stringent features that can lead to complicating the design. In this paper, a new optimizing method based on the inclined planes system optimization algorithm is presented for the design of a discrete power amplifier. It is evaluated in a 2.4-3 GHz power amplifier, which is designed based on “Cree’s CGH40010F GaN HEMT”. The optimization goals are input and output return losses, Power Added Efficiency, and Gain. Large signal simulation of the optimized power amplifier shows a good performance across the bandwidth. In this frequency range, the input and output return losses are about lower than -10 dB, the Power Added Efficiency is greater than 51%, while the Gain is higher than 13.5 dB. A two-tone test with a frequency space of 1 MHz is applied for the linearity evaluation of the designed power amplifier. The obtained result shows that the power amplifier has good linearity with a low memory effect.
Yanawati Yahya, Nor Shafiqin Shariffuddin, Muhammad Khairul Hisyam Jarail, Dina Maizana, Phd Ibrahim Alhamrouni, Mohd Khairil Rahmat,
Volume 21, Issue 2 (6-2025)
Abstract
Induction motors are highly favored in industrial applications for their ease of operation, compactness, lightweight, efficiency, low maintenance, and cost-effectiveness. They are widely used in conveyors, compressors, crushers, drills, fans, escalators, refrigerators, and electric vehicles. In Malaysia, industrial motors account for about 48% of energy consumption. This research introduces an improved rotor design with optimized rotor bars. Using MotorSolve (IM) software and theoretical calculations, the study found that the new design boosts energy efficiency. The new rotor bar design achieved an energy efficiency of 76.92%, compared to 74% for the current design. In terms of energy efficiency, this research found that adopting high-efficiency motors in industrial applications can save a significant amount of energy. These motors can also be used in a variety of horsepower ranges. The research suggests a maintenance plan for malfunctioning motors that attempts to reduce energy consumption, motor losses, and CO2 emissions in any apparatus. These results offer valuable insights for policymakers to refine energy policies for induction motors. In the future, real-time estimation of the motor's actual operating loss will be required to properly predict the trend in motor efficiency loss under various failure scenarios, which is consistent with the research goal of reducing energy losses in induction motors.
