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This work presents the operation of an autonomous direct current (DC) DC microgrid for residential house controlled by an energy management system based on low complexity fuzzy logic controller of only 25-rules to manage the power flow that supply house load demand. The microgrid consists of photovoltaic (PV), wind turbine, fuel cell, battery energy storage and diesel generator. The size of the battery energy storage is determined based on the battery sizing algorithm depending on the generation of renewables during all seasons of the year in the eastern region of Saudi Arabia. Two scenarios are considered in this work. In the first scenario: the microgrid consists of solar PV, wind turbine, battery energy storage and fuel cell. The fuzzy logic controller is optimized using an artificial bee colony technique in order to increase the system energy saving efficiency and to reduce the cost. In the second scenario: wind turbine is replaced by a diesel generator, also the rated power of the fuel cell is reduced. In this scenario, a new method is proposed to reduce the generation cost of the dispatchable sources in the microgrid by considering economic dispatch within the optimized fuzzy logic energy management system. To obtain the most suitable technique for solving the economic dispatch problem, three optimization techniques were used which are particle swarm optimization, genetic algorithm and artificial bee colony based on real environmental data and real house load demand. A comparison in terms of energy saving between the two scenarios and a comparison in terms of cost reduction between conventional economic dispatch method and the proposed method are presented.

Environmental dust particles repelling from a hydrophobic surface under the electrostatic influence are considered and the dynamics of the dust particles are analyzed incorporating the high speed camera. The velocity of the repelled dust particles are formulated using the force balance incorporating the forces associated with the electrostatic repulsion, particle adhesion, particle drag, and the inflight particles interaction under the charge influence. The functionalized silica particles are deposited on the glass surface towards achieving a hydrophobic wetting state on the surface. An electronic circuitry is designed and built while generating the electrostatic effect, in the pulse form, on the dust particles located on the surface of the hydrophobic plate. Findings revealed that functionalized silica particles deposited surface results in hydrophobic wetting state with contact angle in the order of 158° ± 2° and contact angle hysteresis of 2° ± 1°. The electrostatic impulsive force generated on the plate surface enables to repel most of the sizes of the dust particles; however, some of the small dust particles remain as the residues on the surface after the electrostatic influence. The dust particle velocity predicted from the analytical formulation agrees with that obtained from the high speed camera data. The pinning force of the small size particles (0.6 µm≤), due to adhesion on the surface, is found to be larger than the average size particles (∼1.2 µm), which in turn, suppresses these particles repelling from the surface under the electrostatic influence. The residues of the dust particles on the as received glass surface after dust repelling are more than those residues on the hydrophobic surface. This behavior is associated with the dust particles adhesion on the surface. Consequently, hydrophobic wetting state on the plate surface improves the dust particle repelling from the surface.

Saudi Arabia is characterized with high temperature, humidity, and dust storms. The air conditioning systems are an essential component in daily life. 60% of the energy consumed in the residential area is used by air conditioning systems. The aim of this paper is to build a residential thermal HVAC model, which could predict the amount of energy consumption required to get the comfort level using Matlab/Simulink. In this model the different physical properties of the building, weather, and heating gains are taken to account. The results of energy consumption obtained from Matlab/Simulink model are based on using the actual hourly outdoor temperature for a selected day of 2012 compared to the average outdoor temperature of the same selected day. The results of energy consumption for the actual and average temperatures are almost identical. For this reason, the results of total energy consumption are presented in this paper for every day of the annual year of 2012 based on the average hot and warm outdoor temperatures (7 1/2 months), and cool and cold temperatures (4 1/2 moths).

The ferro-liquid droplet manipulation on hydrophobic surfaces remains vital for various applications in biomedicine, sensors and actuators, and oil–water separation. The magnetic influence of ferro-liquid droplets on the hydrophobic surface is elucidated. The mechanisms of a newborn droplet formation under the magnetic force are explored. The sliding and rolling dynamics of the ferro-liquid droplets are assessed for the various concentrations wt % of ferro-particles. High-speed recording and a tracker program are used to evaluate the droplet sliding and translational velocities. It is demonstrated that the mode of droplet motion changes from sliding to rolling as the magnetic Bond number increases, in which case, the droplet position becomes close to the magnet surface. The translational velocity of the droplet under rolling mode increases as the ferro-particle concentration in the droplet fluid increases. A further increase of the magnetic Bond number results in the creation of a newborn droplet attached to the magnet surface.

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A novel speed controller for the trapezoidal three-phase Brushless DC (BLDC) Motor Drive is proposed using a hybrid fuzzy logic/proportional plus integral (PI) control. The structure of the fuzzy logic controller is different from conventional fuzzy logic implementations such that it only uses three simple rules based on speed error being either in the positive, negative or zero regions. The controller outputs a reference current, that is enforced through the motor phases by pulsewidth modulation (PWM) control. The proposed fuzzy logic controller can be used individually in applications requiring lower computation load and tolerating small steady state offset. For high performance applications requiring offset free tracking, a PI controller is augmented with the fuzzy logic controller and a simple switching scheme is devised based on error variance to select the active controller based on operating conditions. The response of the drive system under the proposed composite control structure is compared with the conventional PI based and the sliding mode controllers to demonstrate its improved performance. Simulations studies using detailed models in MATLAB/Simulink's SimPowerSystems toolbox are carried out to show the validity of proposed control.Nov i jednostavan hibridni neizraziti/PI regulator za istosmjerne motore bezčetkica. U ovome radu predlaže se nov regulator brzine za trapezoidalne trofazne istosmjerne motore bezčetkica zasnovan na hibridnom regulatoru. Hibridni regulator sastoji se od dijela s neizrazitom logikom i proporcionano-integracijskog regulatora. Struktura neizrazitog regulatora razlikuje se od konvencionalnih implementacija neizrazitih regulatora po tome što koristi samo tri jednostavna pravila zasnovana na pogrešci brzine u pozitivnom, negativnom ili nultom području. Izlaz regulatoračini referentna struja, koja se šalje na faze motora pomoću širinsko-impulsne modulacije. Predloženi neizraziti regulator može se koristiti i zasebno u primjenama koje zahtijevaju manju računsku složenost i toleriraju malu pogrešku u stacionarnom stanju. Za slučajeve kada je potrebna visoka učinkovitost bez pogreške u stacionarnom stanju, s neizrazitim dijelom proširuje se PI regulator te je razvijen jednostavan postupak promijene regulatora zasnovan na varijanci pogreške. Odziv razmatranog sustava usporeen je s konvencionalnim PI regulatorom i regulatorom u kliznom režimu rada kako bi se pokazala njegova učinkovitost. Izvršene su simulacije u Matlab/Simulinkovom SimPowerSystems alatu kako bi se pokazala ispravnost predloženog postupka.Ključne riječi: istosmjerni motor bezčetkica, neizrazita logika, upravljanje brzinom, hibridno upravljanje