ملخص البحث :

This paper discusses various aspects of a single-ended primary inductance DC-DC converter (SEPIC). The focus is on design, modelling, and simulation results of a SEPIC converter. The study analyses the principle of SEPIC operation when operated in continuous conduction mode (CCM). Additionally, the mathematical equations for the design modules are calculated as per converter requirements. State-space equations are used to formulate the state-space model of the SEPIC converter. To satisfy the bestperformance criterion of the system, the parameters for controller (Kp, Ki, Kd) should be tuned or optimized using the genetic algorithm (GA) optimization technique. Controller parameters are determined using an objective function that minimises the integral time absolute error (ITAE). Simulations performed on a closed-loop system reveal that the step response with a PID controlled based GA displayed superior performance. A closedloop system has a substantially bigger stability region compared to an openloop system. The simulation optimised performance metrics like maximum overshoot percentage (Mp), rise time (tr), and settling time (ts). MATLAB/Simulink R2018a® and m-file code are used for the system modelling, simulation, and optimization of the PID controller parameters based on the GA

ملخص البحث :

In power electronics, it is necessary to select the best converter circuit topology that has good performance among different converters. The singleended primary inductor converter (SEPIC) has good performance and is advantageous among different direct DC/DC converters. In this paper, a design of a SEPIC converter is made by selecting the values of its components according to the required output voltage and power. The design is made by an assumption that both of its inductors have the same value. The converter is tested by using MATLAB/Simulink successfully. Later, its output voltage is regulated by using a proportional integral (PI-controller) through tuning its proportional and integral gains. Finally, the SEPIC converter is connected to a single-phase full-bridge inverter to supply its required DC voltage. The role of the SEPIC converter is to regulate the dc-link voltage between its output side and the inverter. The results showed the success of this connection to supply alternating current (AC) loads with low total harmonic distortion (THD).

ملخص البحث :

: Grid-connected hybrid energy systems (HESs) represent a very promising option for addressing the problem of power outages worldwide. The selection of a suitable optimization approach and operational strategy are important aspects of the optimal design and operation of these HESs. This study aimed to find the optimal grid-connected PV/battery system sizes to supply electricity for a residential house in Karbala, Iraq, using two control strategies, load following (LF) and cycle charging (CC). The optimization was performed using HOMER software with and without the multi-year effects. The comparison analysis was carried out by considering the techno-economic and environmental performance of the feasible systems. The simulation results indicate that optimal configuration is achieved by using the CC strategy. Furthermore, the multi-year module affects the optimal results dramatically. Under the CC strategy, the multi-year effects increase the required PV size from 6 kW to 7 kW and the required number of batteries from 18 to 20, leading to an increase in the net present cost from $26,750 to $33,102 and a decrease in CO2 emissions from 7581 kg/year to 7379 kg/year. The results also show that the optimization results are highly affected by the variations of some critical parameters, such as solar radiation, average load, and battery degradation limits. The achievements indicate the higher effectiveness of the multi-year effects and control strategy on the optimal design of HESs.

ملخص البحث :

In the present time, a profoundly request for the fractal antenna which have the following attributes (1) Packed extent (2) Multiband or broad band as well as (3) Less profile. Also we need to sustain the boundaries of the antenna (for example Efficiency, Directivity, Gain, Return misfortune, also so on). Along headway in correspondence innovation along the previous 10 years, an ascending interest has been found for, cost powerful, miniaturization, broadband, also multiband antennas. The synthesis of fractal antenna might uphold to achieve such prerequisites. Such antennas give a few benefits also yet performance and miniaturization of the fractal antennas might be more improved utilizing decomposition idea. The theory of fractal antenna is worked, similarly with traditional theory of antenna, upon the theory of classic electromagnetic. Actually, the theory of the fractal antenna utilizes a (fractal) or cutting edge calculation which is a zoom augmentation of the Euclidian computations. Furthermore, have important implementation have been found for the fractal antenna in microwave engineering as well as cell communication. Yet, the descending in the antenna extent will cause a moreover decrease in the support bandwidth. Modern topologies of fractal mathematics has been introduced in this paper for miniature strip antennas. The fractal antenna has been planned utilizing three-sided Koch bend with Sierpinski gasket fractal calculations in this article. Also, the work has have been contemplated with dual synthesis proposals of fractal antennas.