281 research outputs found
Magnetically geared induction machines
A wound-rotor induction machine is artfully coupled to a magnetic gear to achieve a high-torque-density drive system called magnetically geared induction machine (MaGIM). The high-speed rotor of MaGIM is common to both the machine and gear sides. A rotating diode rectifier electrically links the machine's wound rotor and a dc boost winding on the gear side to increase the torque-transmission capabilities of the overall system. The first investigations on a 100 kW-120 r/min MaGIM are promising, since an increase in torque of ∼ 15% could be obtained by inserting the diode rectifier. For fixed speed applications, this induction-machine-based system can be directly supplied from the main
Garhy-Generated Family of Distributions with Application
This paper introduces a new family of continuous distributions called a Garhy generated family of distributions. Some mathematical properties of this family are discussed. The derived properties are hold to any proper distribution in this family. Some special sub-models in the new family are derived. General explicit expressions for the quantile function, ordinary and incomplete moments, generating function and order statistics are obtained. The estimation of the model parameters is discussed by using maximum likelihood and the potentiality of the extended family is illustrated with one application to real data. Keywords: Kumaraswamy distribution; Exponetiated distribution; Moments; quantile function, Maximum likelihood estimation
Modelling and control of a multi-stage interleaved DC-DC converter with coupled inductors for super-capacitor energy storage system
Interleaved converters with coupled inductors are widely used to share load current in high power applications. It offers high equivalent switching frequency and reduced output current ripples using small size magnetic components. Due to smaller common-mode inductance, control system can be designed to achieve fast dynamic response. This paper proposes 8 channel interleaved DC/DC converter for interfacing super-capacitor energy storage system to a 400V DC voltage bus. Multi-stage interleaving magnetic circuit with two-phase coupling inductor as a building block is proposed. A methodology is developed to construct the model of the multi-stage magnetic circuit from the basic two-phase coupled inductor model. The derived model is successfully used to evaluate the system power losses and to design the magnetic circuit parameters and its current controller to fulfil the DC/DC converter steady state and dynamic performance specifications. A 20kW/four stage/8 channel DC/DC converter laboratory prototype has been built to connect a super-capacitor stack to 400V DC voltage bus. Experimental investigation validates the modeling, the system losses calculations and the design specifications of the system
Effect of dietary microalgae on growth performance and health in meat-type quails
The purpose of this work was to ascertain the impact of dietary inclusion of Dunaliella salina
(Ds) and Arthrospira platensis (Ap) mixture as growth promoters on growth performance,
carcass traits, liver and renal function, lipid profile, immunology and economics in quail
chicks. 240 Un -sexed seven-day quail chicks were separated into four treatment groups with
six replicates of ten chicks per group. The treatment groups are: control: basal diet; DsAp0.5:
basal diet + 0.25 g Ds+ 0.25 g Ap/kg diet; DsAp1: basal diet + 0.50 g Ds+ 0.50 g Ap/kg diet;
and DsAp2: basal diet + 1.00 g Ds+ 1.00 g Ap/kg diet. The outcomes of dietary inclusion of
Ds plus Ap revealed a significant difference in live body weight at 5 week and body weight
gain from (1-5wk) (P=0.049) and the group DsAp1 recorded the best results (191.19g, 5.69g).
The mixture of Ds plus Ap did not significantly (P>0.05) change the feed intake during the
experiment. The DsAp0.5 group significantly (P=0.019) presented the best feed conversion
ratio during (1-5 wk of age) compared to the control and other groups. The finding showed a
non-significant difference in carcass traits (P>0.05). Liver and kidney function markers were
affected by the supplements, and DsAp2 group recorded the highest levels of total protein and
albumin. The DsAp1 group significantly (P=0.003) presented the lowest level of alanine
aminotransferase (ALT) and the DsAp2 group significantly (P<0.001) presented the lowest
levels of aspartate aminotransferase (AST) and urea. Dietary supplementation of Ds plus Ap
affected the lipid profiles of the quail. Dietary supplementation of Ds plus Ap mixture
reduced the concentration of total cholesterol (TC), low-density lipoprotein (LDL),
triglyceride (TG) and high-density lipoprotein (HDL) when compared to control (P<0.001).
Furthermore, the immune parameters, complement 3 (C3) and lysozyme showed a nonsignificant
variation with Ds plus Ap supplementation. The net revenue and economic
efficiency of treated quails was significantly increased during the experiment (1-5 wks of
age); the best values were observed in DsAp0.5 group. In conclusion, the use of Ds plus Ap
mixture as growth promoters in quail diets improves the growth performance, liver functions
and lipid profile
Power management and control strategies for off-grid hybrid power systems with renewable energies and storage
This document is the Accepted Manuscript of the following article: Belkacem Belabbas, Tayeb Allaoui, Mohamed Tadjine, and Mouloud Denai, 'Power management and control strategies for off-grid hybrid power systems with renewable energies and storage', Energy Systems, September 2017. Under embargo. Embargo end date: 19 September 2018. The final publication is available at Springer via https://doi.org/10.1007/s12667-017-0251-y.This paper presents a simulation study of standalone hybrid Distributed Generation Systems (DGS) with Battery Energy Storage System (BESS). The DGS consists of Photovoltaic (PV) panels as Renewable Power Source (RPS), a Diesel Generator (DG) for power buck-up and a BESS to accommodate the surplus of energy, which may be employed in times of poor PV generation. While off-grid DGS represent an efficient and cost-effective energy supply solution particularly to rural and remote areas, fluctuations in voltage and frequency due to load variations, weather conditions (temperature, irradiation) and transmission line short-circuits are major challenges. The paper suggests a hierarchical Power Management (PM) and controller structure to improve the reliability and efficiency of the hybrid DGS. The first layer of the overall control scheme includes a Fuzzy Logic Controller (FLC) to adjust the voltage and frequency at the Point of Common Coupling (PCC) and a Clamping Bridge Circuit (CBC) which regulates the DC bus voltage. A maximum power point tracking (MPPT) controller based on FLC is designed to extract the optimum power from the PV. The second control layer coordinates among PV, DG and BESS to ensure reliable and efficient power supply to the load. MATLAB Simulink is used to implement the overall model of the off-grid DGS and to test the performance of the proposed control scheme which is evaluated in a series of simulations scenarios. The results demonstrated the good performance of the proposed control scheme and effective coordination between the DGS for all the simulation scenarios considered.Peer reviewedFinal Accepted Versio
Duobinary modulation/predistortion techniques effects on high bit rate radio over fiber systems
The work has presented duobinary modulation and predistortion techniques for the radio over fiber system enhancement for achieving security level. Duobinary modulation technique has more compact modulated spectral linewidth with standard non return to zero modulation code. Different NRZ/RZ rectangle shape employed that are namely exponential rectangle shape (ERS), and Gaussian rectangle shape (GRS) for different transmission bit rates. Switching bias voltage, and switching RF voltage based LiNbO3 modulator are changed to measure the performance parameters of the radio over fiber (RoF) system. Predistortion technique improves the linearity of transmitter amplifiers and it is considered as a power efficiency technique. The optimum values of the Q-factor, data error rate (BER), electrical power, signal gain, noise figure, and light signal/noise ratio are achieved with 8 Volt for both switching biases/switching RF signal at 100 GHz. Signal quality/BER and electrical power after the receiver enhancement ratio by using this technique at different RF signal frequencies.
High speed pulse generators with electro-optic modulators based on different bit sequence for the digital fiber optic communication links
The paper outlines the simulation of various pulse generators for the enhancement of optical fiber access transmission networks within flow rate of 10 Gbps and transmission range of 100 km. The pulse generators are gaussian, hyperbolic secant, triangle, sine, raised cosine in the transmission stage. Proposed pulse generators are mixed with both electro-absorption modulator (EAM) and mach-zehnder modulator (MZM) for efficient transmission. We have compared the max. the quality factor with using proposed pulse generators against nonreturn to zero (NRZ) return to zero (RZ) pulse generators in the previous research works for different bit sequences. The signal power amplitude is tested for both optical fiber and PIN photodetector optical time-domain visualizer and RF spectrum analyzer by using in the optimum cases for different bit sequence. It is observed that proposed pulse generators/EAM have presented an efficient increase in Q-factor value compared with proposed pulse generators/MZM for different bit sequences
The key management of direct/external modulation semiconductor laser response systems for relative intensity noise control
This study outlines the management of either direct or external modulation semiconductor laser systems for the key solution of bit rate up to 25 Gb/s under relative intensity noise (RIN) control. The bias and modulation peak currents based laser rate equations are optimized to achieve max Q factor and min bit error rate (BER) using first proposed model and optical/electrical signal power, optical/electrical signal to noise ratio are also enhanced using second proposed model. The percentage enhancement ratio in max. Q-factor and min. BER using first proposed model ranges from 53.25 % to 71.63 % in compared to the previous model. In the same way, by using second proposed model, the electrical signal power at optical receiver is enhanced within the range of 48.66 % to 68.88 % in compared to the previous model. Optical signal/noise ratio (OSNR) after optical fiber cable (OFC), signal/noise ratio (SNR) after electrical filter are measured with using different electrical pulse generators and electrical modulators at the optimization stage. The first proposed model reported better max. Q and min. BER values than the previous model. In addition to the second proposed model (direct modulation) has outlined better optical/electrical signal power than the previous model, while max. Q, min. BER values are kept constant. It is found that non return to zero pulse generator has presented better signal power than other pulse generators by using second proposed model. As well as the mixed of raised cosine pulse generator with external modulator reported max. Q, min. BER with other pulse generators by using first proposed model. OSNR at OFC is optimized by using continuous phase frequency shift keying (CPFSK) electrical modulator, While SNR at optical receiver is optimized by using phase shift keying (PSK) electrical modulator
High modulated soliton power propagation interaction with optical fiber and optical wireless communication channels
This paper has presented high modulated soliton power transmission interaction with optical fiber and optical wireless communication channels at flow rate of 40 Gbps and 20 km link range. The proposed modulation schemes are continuous phase frequency shift keying (CPFSK), Quadrature amplitude modulation (QAM), differential phase shift keying (DPSK), frequency shift keying (FSK), pulse amplitude modulation (PAM), minimum shift keying (MSK), and optical quadrature phase shift keying (OQPSK). CPFSK has presented better performance than other proposed modulation schemes for both optical fiber and optical wireless communication channels. The enhancement of optical signal/noise ratio at fiber/wireless channel, received electrical power and signal/noise ratio at optical receiver with increase of bits per symbol for different proposed modulation schemes except for CPFSK scheme. Therefore it is evident that CPFSK modulation scheme is more efficient and better performance than other modulation schemes for different communication channels. The obtained results are simulated with optisystem program version 13
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