-
High-Performance Multilevel Inverter Drive of Brushless DC Motor
Yousif Ismail Al Mashhadany
Issue:
Volume 4, Issue 3-1, May 2015
Pages:
1-7
Received:
15 October 2014
Accepted:
20 October 2014
Published:
25 October 2014
DOI:
10.11648/j.ijrse.s.2015040301.11
Downloads:
Views:
Abstract: The brushless DC (BLDC) motor has numerous applications in high-power systems; it is simple in construction, is cheap, requires less maintenance, has higher efficiency, and has high power in the output unit. The BLDC motor is driven by an inverter. This paper presents design and simulation for a three-phase three-level inverter to drive the BLDC motor. The multilevel inverter is driven by discrete three-phase pulse width modulation (DPWM) generator that forced-commuted the IGBT’s three-level converters using three bridges to vectored outputs 12- pulses with three levels. Using DPWM with a three-level inverter solves the problem of harmonic distortions and low electromagnetic interference. This topology can attract attention in high-power and high-performance voltage applications. It provides a three-phase voltage source with amplitude, phase, and frequency that are controllable. The proposed model is used with the PID controller to follow the reference speed signal designed by variable steps. The system design is simulated by using Matlab/Simulink. Satisfactory results and high performance of the control with steady state and transient response are obtained. The results of the proposed model are compared with the variable DC-link control. The results of the proposed model are more stable and reliable.
Abstract: The brushless DC (BLDC) motor has numerous applications in high-power systems; it is simple in construction, is cheap, requires less maintenance, has higher efficiency, and has high power in the output unit. The BLDC motor is driven by an inverter. This paper presents design and simulation for a three-phase three-level inverter to drive the BLDC mo...
Show More
-
Performance Enhancement of PV Array Based on Water Spraying Technique
Salih Mohammed Salih,
Osama Ibrahim Abd,
Kaleid Waleed Abid
Issue:
Volume 4, Issue 3-1, May 2015
Pages:
8-13
Received:
19 October 2014
Accepted:
7 November 2014
Published:
11 November 2014
DOI:
10.11648/j.ijrse.s.2015040301.12
Downloads:
Views:
Abstract: This paper experimentally presents water spraying technique to improve photovoltaic (PV) array efficiency and enhance the net power saving. A forced-water spraying and cooling technique with constant flow rate of water on PV array surface is designed and implemented. The decreasing rate in the panel surface temperature has a direct proportional relation with PV efficiency. Simultaneously, the output hot water is very beneficial for houses, buildings etc., as water heating system, specifically in the remote areas. The electrical performance of PV array was also studied. The cooling rate of panel surface for 5 min.= 4 in midday. The electrical performance of PV array also was studied. As a final point, the economical results were achieved as result of the power saving increases 7w/degree at midday.
Abstract: This paper experimentally presents water spraying technique to improve photovoltaic (PV) array efficiency and enhance the net power saving. A forced-water spraying and cooling technique with constant flow rate of water on PV array surface is designed and implemented. The decreasing rate in the panel surface temperature has a direct proportional rel...
Show More
-
High Performance for Real Portable Charger through Low-Power PV System
Yousif I. Al-Mashhadany,
Hussain A. Attia
Issue:
Volume 4, Issue 3-1, May 2015
Pages:
14-18
Received:
29 October 2014
Accepted:
10 November 2014
Published:
12 November 2014
DOI:
10.11648/j.ijrse.s.2015040301.13
Downloads:
Views:
Abstract: This paper proposes a novel design for a solar-powered charger for low-power devices. The level of the charging current is controllable and any residue power is saveable to a rechargeable 9V battery. Two power sources (AC and solar) are used, and two charging speeds are possible. Quick charging is 20% of the battery output current (almost 180mA/hr) so the current is limited to 34 mA. Two types of cellular batteries (5.7V and 3.7V) can be charged. Normal charging is 10% of the cellular battery output current (almost 1,000mA/hr), so the charging current is limited to 100mA. The design uses only a few components so the system is cost effective besides being highly portable. It was simulated on MultiSim Ver. 11 before being implemented practically to validate it. The results from the simulation and the experiment show the design’s sufficient feasibility for practical implementation.
Abstract: This paper proposes a novel design for a solar-powered charger for low-power devices. The level of the charging current is controllable and any residue power is saveable to a rechargeable 9V battery. Two power sources (AC and solar) are used, and two charging speeds are possible. Quick charging is 20% of the battery output current (almost 180mA/hr)...
Show More
-
Experimental Analysis on Thermal Efficiency of Evacuated Tube Solar Collector by Using Nanofluids
Hashim A. Hussain,
Qusay Jawad,
Khalid F. Sultan
Issue:
Volume 4, Issue 3-1, May 2015
Pages:
19-28
Received:
22 October 2014
Accepted:
7 November 2014
Published:
24 November 2014
DOI:
10.11648/j.ijrse.s.2015040301.14
Downloads:
Views:
Abstract: This research is to study performance of a evacuated tube solar collector when silver (Ag(30nm)) + distilled water and oxide titanium (ZrO2(50nm)) + distilled water nanofluids was taken as the working fluid. With higher thermal conductivity of the working fluid the solar collector performance could be enhanced compared with that of distilled water. The two types of nanoparticles are used to investigate at different concentration (i.e. 0, 1, 3 and 5 % vol), mass flow rate (30,60 and 90 lit/hr m2) and the based working fluid was distilled water. The effect of different nanoparticle concentrations of Ag and ZrO2 mixed with distilled water as base fluid was examined on solar collector efficiency for different mass flow rates (30, and 90 lit/hr m2). The area under the curve as an index was used for comparing the effects of mass flow rates and nanoparticle concentrations on the collector total efficiency. The experimental results indicated that the concentration at 1%vol showed insignificant results compared with distilled water. As well as The nanofluids (Ag + DW), at concentrations (1, and 5%vol) and mass flow rates (30, and 90 lit/hr m2), the thermal solar characteristics values of FR(τα), – F RUL were 0.488, 1.168 W/m2.k , 0.593 and 1.252 W/m2.k, while the nanofluid (ZrO2 + DW) 0.437,1.025 W/m2.k ,0.480 and 1.140 W/m2.k respectively. Whereas in the case of distilled water at mass flow rates 30 lit/hr m2 and 90 lit/hr m2 were 0.413,0.973 W/m2.k,0.442 and ,1.011 W/m2.k respectively. Moreover use of nanofluids (Ag(30nm) + + distilled water) and( ZrO2(50nm) + distilled water) as a working fluid could improve thermal performance of flat plate collector compared with distilled water, especially at high inlet temperature. The solar collector efficiency for nanofluid (Ag(30nm) + distilled water) was greater than nanofluid (ZrO2(50nm) + distilled water) due to small particle size for the silver compared with zirconium oxide as well as high thermal conductivity for silver. The type of nanofluid is a key factor for heat transfer enhancement, and improve performance of evacuated tube solar collector.
Abstract: This research is to study performance of a evacuated tube solar collector when silver (Ag(30nm)) + distilled water and oxide titanium (ZrO2(50nm)) + distilled water nanofluids was taken as the working fluid. With higher thermal conductivity of the working fluid the solar collector performance could be enhanced compared with that of distilled water....
Show More
-
Simulation of Solar Off- Grid Photovoltaic System for Residential Unit
Issue:
Volume 4, Issue 3-1, May 2015
Pages:
29-33
Received:
27 October 2014
Accepted:
4 December 2014
Published:
19 December 2014
DOI:
10.11648/j.ijrse.s.2015040301.15
Downloads:
Views:
Abstract: The aim of this study is to design a solar off-grid PV system to supply the required electricity for a residential unit. A simulation model by MATLAB is used to size the PV system. The solar PV system is simulated with the case of maximum solar radiation on a sunny day. The results show that the average daily load requirement of the selected residential unit is 36 kWh/day. This load requirement can be meet by using an array of 44 solar panels. During the day time, the PV system supplies the desired 12.4 kWh of energy. During the night time, a battery storage system of 23.6 kWh (48V, 350 Ah) is used to meet the night load.
Abstract: The aim of this study is to design a solar off-grid PV system to supply the required electricity for a residential unit. A simulation model by MATLAB is used to size the PV system. The solar PV system is simulated with the case of maximum solar radiation on a sunny day. The results show that the average daily load requirement of the selected reside...
Show More
-
Behaviour of Ferrocement SlabsContaining SBR Under Impact Loads
Abdulkader Ismail A. Al-Hadithi,
Khalil Ibrahim Aziz,
Mohammed Tarrad Nawar Al-Dulaimi
Issue:
Volume 4, Issue 3-1, May 2015
Pages:
34-50
Received:
27 December 2014
Accepted:
30 December 2014
Published:
14 January 2015
DOI:
10.11648/j.ijrse.s.2015040301.16
Downloads:
Views:
Abstract: The main aim of this work is to investigate the behavior of Ferrocement slabs under impact loading. A total of 48 Ferrocement slabs were constructed and tested, 36 slabs tested under low velocity impact and 12 slabs tested under high velocity impact, in addition,the main parameter considered in the present investigation was number of wire mesh layers, content of (SBR) polymer andheight of falling mass (falling velocity). For low velocity impact,This test was performed in terms of the number of blows required to cause first crack and ultimate failure. The test was applied on square slabs of dimensions (500 × 500 × 50 mm) subjected to repeated impact blows by falling mass (1300 gm) dropped from three heights (2.4 m) , (1.2 m) and (0.83 m) at 56 day age. The number of required blows for the first crack and final failure was recorded. The mode of failure and the crack pattern were also observed. For high velocity impact test, a (500×500×50 mm) slabs were tested by 7.62 mm bullets fired from a distance of (15m) with a striking velocity of (720m/sec.). The spalling, scabbing and perforation were observed and discussed. The results exhibited that the number of blows which were required to make the first crack and failure, increased with increase of polymer content and number of wire mesh layers. Also for high velocity impact test, it can be noted that the area of scabbing and area of spalling decreased with the increase of polymer content and number of wire mesh layers compared with reference mixes. The compressive strength, splitting tensile strength and flexural strength increased with increase the polymer content. Based on extensive works , found that low velocity impact resistance of polymer modified Ferrocement slabs was greater than the reference mix slabs, it was found that the number of blows that needed to produce the first crack and ultimate failure increased with increase the polymer ratio of 3% to 5% and to 10%, and with increased the number of layers of reinforcing with wire mesh when comparing these results reference mix.
Abstract: The main aim of this work is to investigate the behavior of Ferrocement slabs under impact loading. A total of 48 Ferrocement slabs were constructed and tested, 36 slabs tested under low velocity impact and 12 slabs tested under high velocity impact, in addition,the main parameter considered in the present investigation was number of wire mesh laye...
Show More
