Majlesi Journal of Energy Management
Volume:7 Issue: 4, Dec 2018

Refractory materials are non-metallic materials with high melting point, inert to chemical corrosion and maintain their structural properties at high temperature. This research evaluated the physical properties such as bulk density, apparent porosity, linear shrinkage, cold compressive strength, thermal shock resistance, loss on ignition and refractoriness of Alkaleri clay with rice husk ash (RHA) admixture using design expert 7.1.6 Central Composite Design (CCD). The physico-chemical properties of Alkaleri clay and rice husk ash ( RHA ) from Rafin zurfi, Yelwa in Bauchi State was characterized using Energy Dispersive X-ray Fluorescence Spectrometry (ED-XRFS), the result show that Alkaleri clay has 33.3wt% of aluminum oxide (Al2O3) and 46.35wt% of silicate oxide (SiO2), hence the clay belongs to alumino-silicate clay while the RHA has 74.2wt% of silicate oxide  and 8.52wt% of potassium oxide (K2O) that is responsible for its pozzolanic effect, 2.0% of magnesium oxide (MgO) and 4.09% of calcium oxide (CaO) that is responsible for its  increase in bonding strength with the clay. From the optimization results, desirability of 0.617 suggested an optimum refractory property at 88.75g of Alkaleri clay and 14.22g of RHA. The refractory properties corresponding to this desirability is apparent porosity of 22.3536%, cold crushing strength (CCS) of 2.0838kN/cm2, firing shrinkage of 3.214%, bulk density of 1.92084g/cm3, loss on ignition (L.O.I) of 9.3099%, thermal shock resistance of 14.7424 cycles and refractoriness of 1595.99OC. These results fall within ASTM standard of refractory material for ferrous casting.

In this paper, we present a comparative study between pulse width modulation (PWM) and new space vector pulse width modulation (SVPWM) technique in fuzzy sliding mode control (FSMC) of reactive and active power command of a doubly fed induction generator (DFIG) for wind turbines. Two commands approches using FSMC-SVPWM and FSMC-PWM are proposed and compared. The validity of the proposed commands schemes is verified by simulation tests of a DFIG. The reactive power, stator current and active power is determined and compared in the above techniques. The obtained results showed that, the proposed FSMC with SVPWM technique have reactive and active power with low powers ripples and low stator current harmonic distortion than PWM technique.

One of the problem facing developing countries and particularly an urban city like Lagos in Nigeria is the issue of poor waste management by citizen. This definitely affects the standard of living of both the humans being and animals. Spread of diseases, foul smell in the air and unpleasant look of the city are few of its consequences. The cause of this can be trace to either non availability of Dustbins within the vicinity or their addresses and locations are not known. In the development of smart city dustbin mobile application for android, such problems are taking in to consideration. Its result generates a mobile Android app called Smart Dustbin that have Database which contain the proposed names and addresses for different dustbins. These are displayed on the screen of any Android mobile Smartphone’s the app is installed on and can then be used to locate the dustbin within the user’s vicinity. If a particular address is not descriptive enough or the precise location of the dustbin is proofing difficult for the user, such dustbin can be click. This will launch a goggle map, search with the address and bring the precise location of the dustbin with other relevant information that will guide the user.

Unreliability in continuous production poses challenges for deploying renewable sources in a real- time power delivery system. Output intermittency, and reliability issues can be potentially addressed by employing suitable combination of the two RE sources technologies (PV and WT) together with the use of an energy storage system, such as battery energy storage system (BESS), as a type of power balancing medium. Different storage options could address this unreliability issue, but they consume electrical energy and create significant costs and carbon emissions. An alternative is using electric vehicles and plug-in electric vehicles, with two-way power transfer capability (Grid-toVehicle and Vehicle-to-Grid), as temporary distributed energy storage devices. In this paper, first the benefits of two solar and wind resources is investigated by each other in a weak Low Voltage Distribution Grid and It is shown that these two resources together can eliminate the challenges of generating stochastic nature of renewable resources. Also, the behavior a weak power distribution grid at the Point of Common Coupling (PCC) in the presence of a photovoltaic generator, wind and electric vehicle has been analyzed. Finally, transient stability has been analyzed in different fault conditions. Simulative analysis is performed in the DIgSILENT PowerFactory software.

In this work, we present a new super-twisting sliding mode controller (STSMC) for wind turbine based on a doubly-fed induction generator (DFIG) using fuzzy logic (FL) and artificial neural network (ANN). This work presents a direct torque control (DTC) and intelligent STSM algorithm of a DFIG-based wind turbine for independent control of rotor flux and electromagnetic torque. For a comparative study, the independent control of rotor flux and torque is ensured in the first step by DTC with neural STSM controllers (DTC-NSTSMC) and the second step by DTC with fuzzy STSM controllers (DTC-FSTSMC). Finally, the performance of the system is tested and compared by simulation in terms of robustness tests, and pursuit tests based on Matlab/Simulink software.

At present, the whole world is going through a severe energy crisis due to the non replenish able nature of fossil fuels which are major sources of conventional energy. In addition to limited availability of conventional energy sources, they also contribute heavily towards environmental pollution. In this scenario, renewable energy sources has got significant role to play in meeting global energy demand. Solar and wind energy systems are the most popular types of grid connected renewable energy systems. We are presenting a new system configuration for interfacing the hybrid solar and wind energy system to the grid. This configuration is flexible and it allows these two renewable energy sources to supply the load together or independently depending upon their availability. The configuration proposed here uses a modified five-level inverter for converting DC voltage generated from renewable energy sources to AC voltage at desired frequency. The usage of five-level inverter reduces Total Harmonic Distortion (THD) in output voltage and helps in eliminating bulk filters required at the output side. Simulation study of the proposed system is carried out using MATLAB Simulink.