-
Fiber Fuse Simulation in Hollow-Core Photonic Crystal Fibers
Issue:
Volume 10, Issue 3, June 2022
Pages:
71-79
Received:
2 May 2022
Accepted:
17 May 2022
Published:
26 May 2022
DOI:
10.11648/j.jeee.20221003.11
Downloads:
Views:
Abstract: Recently great interest has been aroused by the development of photonic crystal fibers (PCFs). Hollow-core photonic crystal fibers (HC-PCFs) can guide light inside the hollow core by photonic bandgap or inhibited-coupling mechanisms. HC-PCFs exhibit low propagation losses at 1.064 μm and the 1.51-1.60 μm range. The HC-PCFs are now implemented as an important tool of laser beam delivery in place of traditional single mode optical fibers. One of the problems arising from high-power injection in the optical fiber is the probability of triggering the fiber fuse effect. This effect is related to a heat conduction process in optical fibers. The unsteady-state thermal conduction process in several HC-PCFs (revolver fibers) for high-power transmission was studied theoretically by the explicit finite-difference method using the thermochemical SiOx production model. For heat conduction analysis, the complicated inner structure of revolver fiber was simplified using the model composed of silica-ring and air-hole layers. The calculated velocities of fiber fuse propagation in two types of polymer-coated revolver fibers were in fair agreement with the experimental values. If the polymer coating of the revolver fiber is removed, the Fresnel reflection at the outer surface of the support tube occurs and the back-reflected light wave is incident upon the silica capillaries and the hollow core. To clarify the in-phase condition, we estimated phase changes of optical routes in the uncoated revolver fiber. It was found that the reflected waves from the outer surfaces of the silica capillary and support tube are in phase at the core-capillary boundary, and they are mutually enhanced as a consequence of the constructive interference. As a result, the power in the hollow core and the silica capillary was improved for the uncoated revolver fiber compared with the polymer-coated one. The calculated velocity of fiber fuse propagation in the uncoated revolver fiber was in fair agreement with the experimental value.
Abstract: Recently great interest has been aroused by the development of photonic crystal fibers (PCFs). Hollow-core photonic crystal fibers (HC-PCFs) can guide light inside the hollow core by photonic bandgap or inhibited-coupling mechanisms. HC-PCFs exhibit low propagation losses at 1.064 μm and the 1.51-1.60 μm range. The HC-PCFs are now implemented as an...
Show More
-
Implementation of Fractional Voltage and Current Based MPPT Techniques Using PLC and HMI
Maytham Ali Fadhil,
Jawad Radhi Mahmood
Issue:
Volume 10, Issue 3, June 2022
Pages:
80-85
Received:
26 October 2021
Accepted:
16 November 2021
Published:
31 May 2022
DOI:
10.11648/j.jeee.20221003.12
Downloads:
Views:
Abstract: This paper presents the implementation of the two-famous maximum power point tracking (MPPT) techniques used in photovoltaic (PV) system, namely fractional open-circuit voltage (FOCV) and fractional short circuit current (FSCC) based on PLC and HMI in laboratory platform. The real-time operation of these two algorithms in the proposed platform has been done with the help of the DC-DC converter and other components. The main feature of this implementation is using all facilities of the PLC and HMI by the user to control all the essential keys of the two techniques like reference voltage and current sources, PID controller parameters, tracking speed, tracking accuracy, and power curve plotting utility. The purpose of this paper is to clear that, the user or researcher can be used the PLC and HMI to implement any topic related to the PV system such as the implementation of maximum power point tracking techniques or any other subject such as PV modeling or PV simulation even PV panels testing. PLC "programmable logic controller" is a special microprocessor-based controlled system, and it is a special type of computer capable of withstanding the industrial environment like vibration and high temperature. HMI "human interface machine" is used to create a user-friendly interface with the help of its base screens or popup screens. The combination of PLC and HMI is a powerful tool to use in PV system implementation.
Abstract: This paper presents the implementation of the two-famous maximum power point tracking (MPPT) techniques used in photovoltaic (PV) system, namely fractional open-circuit voltage (FOCV) and fractional short circuit current (FSCC) based on PLC and HMI in laboratory platform. The real-time operation of these two algorithms in the proposed platform has ...
Show More
-
A Method of Determining the Recombination Centre Level in High-Speed Power Devices
Yong Taek Pak,
Nam Chol Yu,
KyongIl Chu,
Kum Jun Ryang
Issue:
Volume 10, Issue 3, June 2022
Pages:
86-94
Received:
23 March 2022
Accepted:
10 May 2022
Published:
8 June 2022
DOI:
10.11648/j.jeee.20221003.13
Downloads:
Views:
Abstract: Rational adjusting 3 main parameters of fast p+nn+ structure such as the forward voltage drop, reverse recovery time and reverse current means to control rationally the carrier lifetime of high and low level and the space-charge generation carrier lifetime. In other words, we should make the lifetime of the high-level carrier and the space charge generation carrier as long as possible but the low-level carrier lifetime as short as possible. The best way to satisfying these relations is forming the optimal recombination center level. In this paper, we analyze of optimal recombination center level to adjust rationally the 3 main parameters of fast p+nn+ structure - forward voltage drop, reverse recovery time and reverse current. Forward voltage drop of p+nn+ structure is affected strongly by the high-level carrier lifetime. Reverse current is affected strongly by the low-level lifetime and reverse recovery time is affected strongly by the space-charge generation lifetime. These 3 carrier lifetimes influence 3 main parameters of p+nn+ structure differently. When we decrease the low-level carrier lifetime in order to decrease the reverse recovery time, the forward voltage drop increases and when we increase the high-level carrier lifetime for reducing the forward voltage drop, the reverse recovery time increases. So, in order to adjust these conflicting relations, we will illuminate about the recombination center level formed in the basic floor of p+nn+ structure. On the other hand, to determine the recombination center level coincide with practical recombination center level, we suggest the analytic method of determination the recombination center level formed by 2 carrier lifetime regulation sources.
Abstract: Rational adjusting 3 main parameters of fast p+nn+ structure such as the forward voltage drop, reverse recovery time and reverse current means to control rationally the carrier lifetime of high and low level and the space-charge generation carrier lifetime. In other words, we should make the lifetime of the high-level carrier and the space charge g...
Show More
-
Implementation and Performance Analysis of Z Source Inverter with Space Vector PWM Technique with Low THD Factor and High Gain
Talha Rauf,
Muhammad Furqan,
Saboor Zulifqar,
Saad Rafiq
Issue:
Volume 10, Issue 3, June 2022
Pages:
95-103
Received:
14 April 2022
Accepted:
6 June 2022
Published:
20 June 2022
DOI:
10.11648/j.jeee.20221003.14
Downloads:
Views:
Abstract: In this paper we implement the methodology of three phase Z- source inverter with space vector PWM technique. This inverter has a unique impedance network coupled between the power source and converter circuit to provide the buck boost voltage at the output. This Z network has the ability to boost the input voltage and convert it into alternating current. However, conventional inverters needs the special boost circuit with input to boost up the voltage. That’s why Z source inverter is more efficient than normal inverters because of its single stage boosting and converting. The topology of Z-source inverter can easily be merge with the Renewable resources like Photovoltaic Cells, Fuel cell, wind and motor drives applications. The Advanced techniques like SPWM (Sinusoidal Pulse Width Modulation) and SVM (Space Vector Modulation) enhance its boost capacity and modulation index. To facilitate the understanding of Z source Inverter in this paper we implement this methodology on the system of the 100kW. We compare the output voltage with no load condition and also design the LC filter for the system. The MATLAB simulation and hardware implementation of ZSI with SVPWM on 100kW system gives the output with low THD factor and high voltage gain.
Abstract: In this paper we implement the methodology of three phase Z- source inverter with space vector PWM technique. This inverter has a unique impedance network coupled between the power source and converter circuit to provide the buck boost voltage at the output. This Z network has the ability to boost the input voltage and convert it into alternating c...
Show More
-
Comparative Analysis of the Solar PV Power Plant Efficiency and Output Power at Navrongo in Ghana
Morrison Amenyo Vehe,
Joseph Cudjoe Attachie,
Christian Kwaku Amuzuvi
Issue:
Volume 10, Issue 3, June 2022
Pages:
104-113
Received:
20 May 2022
Accepted:
8 June 2022
Published:
20 June 2022
DOI:
10.11648/j.jeee.20221003.15
Downloads:
Views:
Abstract: In this paper, a comparative analysis of a 2.5 MW grid-connected solar photovoltaic (PV) power plant in Navrongo, Ghana is presented. The measured data from the plant was compared with that of the modelled and simulated results. The modelling was carried out using a genetic algorithm in MATLAB/Simulink. The comparison was based on power and solar irradiation as well as the efficiency of the plant under study. The results showed that, the model yielded increased output power compared with the power output determined from the measured data. This increase in power was observed in all three months; March, July and November 2014. PV module maximum power was more pronounced at a Fill Factor (FF) ranging from 0.5 to 0.8 at higher solar irradiation. Moreover, the efficiency of the modelled PV modules recorded a significant improvement in performance over that of the measured efficiencies for the same period. The monthly daily average measured efficiency value for March was 9.9% compared to 11.4% in the model, indicating a 1.5% increase. In July, however, efficiency increased by 1.0% by comparing the measured and modelled values of 9.6% and 10.6% respectively. November realised a 2.1% rise with a measured value of 11.2% against 13.3% being the modelled value. Conclusively, the study verifies the model’s accuracy to a large extent.
Abstract: In this paper, a comparative analysis of a 2.5 MW grid-connected solar photovoltaic (PV) power plant in Navrongo, Ghana is presented. The measured data from the plant was compared with that of the modelled and simulated results. The modelling was carried out using a genetic algorithm in MATLAB/Simulink. The comparison was based on power and solar i...
Show More
-
Application of Single Channel Blind Source Separation Based-EEMD- PCA and Improved FastICA algorithm on Non-intrusive Appliances Load identification
Gisele Beatrice Sonfack,
Philippe Ravier
Issue:
Volume 10, Issue 3, June 2022
Pages:
114-120
Received:
21 May 2022
Accepted:
8 June 2022
Published:
20 June 2022
DOI:
10.11648/j.jeee.20221003.16
Downloads:
Views:
Abstract: The deployment of NILM systems and others embedded systems in the residential sector provides a large amount of data to better understand the electricity consumption habits of occupants in order to provide energy optimization solutions. The Fast Fixed-Point Algorithm for Independent Component Analysis (FastICA) can be used in the identification of loads through the separation of aggregated current and voltage waveforms from devices in the operating conditions that ensure the time and/or frequency independence between the sources. However, in addition to being less suitable for under-determined systems, the FastICA algorithm is sensitive to the initial weight vector, which affects the convergence of the algorithm. In order to solve this problem, a combination of Signal processing methods has been proposed to extract individual current curves representing load profiles from the single channel observation. First, the current mixed signal was decomposed using the EEMD algorithm to obtain IMFs for use in the BSS. As the number of IMFs is very large, the PCA algorithm was used to reduce the number of IMFs from n to r. Selected principal components were whitened and an over-relaxation factor was incorporated into the iterative Newton algorithm to process the randomly generated initial weight vector. The improved FastICA algorithm was used to separate the source components, selected the best current source from the mixed observation. Finally, the individual current analyzes and compares to the original signal. The advantage of this approach lies in the fact that it applies perfectly to NILM applications where very often only one observation is available, which is the aggregated signal. Moreover, it reveals the importance of the data sampling frequency for an accurate characterization of the load profile.
Abstract: The deployment of NILM systems and others embedded systems in the residential sector provides a large amount of data to better understand the electricity consumption habits of occupants in order to provide energy optimization solutions. The Fast Fixed-Point Algorithm for Independent Component Analysis (FastICA) can be used in the identification of ...
Show More
-
Possibility of Bending-Induced Fracture in Curved Double-Clad Fibers
Issue:
Volume 10, Issue 3, June 2022
Pages:
121-127
Received:
12 June 2022
Accepted:
24 June 2022
Published:
29 June 2022
DOI:
10.11648/j.jeee.20221003.17
Downloads:
Views:
Abstract: Rare-earth-doped optical fibers are one of the most promising solid-state lasers. In these fiber lasers, a cladding-pumping scheme using large-mode-area double-clad fibers (DCFs) is utilized to increase the overall conversion efficiency of pumping light and to overcome the restriction owing to the onset of stimulated Raman scattering. On the other hand, it is extremely challenging to increase the fiber core size while retaining the excellent beam quality because fibers with large core size allow propagation of several higher-order modes (HOMs), except for the fundamental mode (FM). In order to suppress HOMs, DCFs are bent with a relatively small bend radius. For the bent DCFs, the fracture behavior, including delayed fracture, was investigated on the basis of the fracture mechanics concept. When a bent DCF is subjected to a high applied stress, failure occurs by the extension of a crack from the surface of the inner cladding (silica glass) layer of the DCF. When DCFs with core diameters of 20 and 40 μm were curved to be stored in the apparatus to maintain large bending radii of > 245 and 275 mm, respectively, it was found that both instantaneous and delayed fracture of bent DCFs could not occur in either air or distilled water. When a DCF is homogeneously curved in air and in water, bending loss occurs in the core and the optical power lost in the core is emitted from the outer interface (or boundary) between the inner cladding (silica glass) and outer cladding (low-index polymer) layers. As the transmittance of the polymer is not 100%, the leaked light is absorbed and heat accumulates in the polymer. The heat generated in the polymer through the absorption of optical power is transferred to the neighboring cladding (silica glass) layer. When the temperature of the outer wall of the cladding layer is higher than that of the inner wall, tensile stress is generated on the inner wall and compressive stress is generated on the outer wall. The thermal stress generated on the inner wall was estimated. It was concluded that the instantaneous fracture of curved DCFs could not occur in air or in distilled water under high-power laser operation.
Abstract: Rare-earth-doped optical fibers are one of the most promising solid-state lasers. In these fiber lasers, a cladding-pumping scheme using large-mode-area double-clad fibers (DCFs) is utilized to increase the overall conversion efficiency of pumping light and to overcome the restriction owing to the onset of stimulated Raman scattering. On the other ...
Show More
