Can, Erol; Gülnahar, Murat

DC-DC converters are circuits that are widely used in energy distribution systems, in industry and technology applications, as well as in household appliances such as computers and televisions, and in uninterruptible power supplies used to feed all these systems. For the design and optimization of DC-DC converter circuits, it is important to create and analyze mathematical models according to the load it is connected to. Simple load structures and circuit structures have been examined and control units have been designed in studies carried out to date. In this study, while the DC-DC converter with a more complex load structure is discussed, mathematical analysis and PID control of DC-DC converters with Buck-Boost feature are performed with the same modulation index in different time periods. In the results obtained, it is shown how to create the mathematical models of a system that provides DC-DC energy conversion with a complex load structure and how to formulate the PID control in a system with this complex load structure.

Akgül, I˙smail; Yavuz, Ömer Çağrı; Yavuz, Uğur

Diabetic retinopathy (DR) is an important disease that occurs because of damage to the retinal blood vessels in the human eye due to diabetes and causes blindness. If diagnosed correctly, the treatments to be applied increase the possibility of preventing vision loss or blindness. This study aims to present an evaluation of deep learning methods to detect diabetic retinopathy from retinal images. In this direction, the VGG16 model was considered, and two different versions of this model were obtained by making improvements. Besides, a model has been proposed, the first layers are dense, the next layers have decreasing convolution, and have fewer layers. According to the results, the VGG16 model, which reached 75.48% accuracy, reached 76.57% accuracy due to the dropout layer added to the classification layers, and 77.11% accuracy due to the dropout layer added to all blocks. The highest accuracy was obtained in the proposed model with 81.74%.

Can, Erol

The paper presents an application of power control by couple half wave LPWM rectifiers processing at the energy distribution line. The switching method with the components of semiconductor for alternating energy control in the energy distribution line is used on alternating energy sources. In three-phase power line and load, power control and regulation are done with the proposed modulation correction index (MCI). Therefore, the simulation model of 3-phase energy distribution is established after the relationships between the energy sources and the circuit elements are determined by the circuit analysis method. The controls of the current and the voltage are done by trying at the different loads in the line at the simulation. According to the modulation correction index (MCI), currents of unbalanced loads are balanced by the proposed method on the power line. Then, the balance currents and powers that MCI provides are calculated. Finally, a power line of 15 km at length that is created by connecting the model of RLC is tested. Obtained results show the effectiveness of the proposed method.

Can, Erol

The design and development of DC-DC converter circuits are important for increasing and decreasing the direct current energy sources at operating the loads and systems. In this study, a multi DC-DC converter structure is described. The purpose of creating this circuit structure is to create a more effective circuit by offering a different circuit structure. For the proposed DC-DC converter, a circuit structure with five switches is created. This circuit structure is described by mathematical models according to the operation of the four parts PWMs in different time periods. After the mathematical analysis of the circuit structure, the proposed circuit and conventional circuit are operated in the Matlab Simulink. The obtained results are compared. According to the comparisons, the proposed circuit produces a higher output voltage than the traditional one and has a higher performance. Additionally, the circuit is operated for values of different loads using different switching times. Finally, voltages and currents are observed on loads.

Can, Erol

This article deals with the energy transmission line system which feeds from solar energy at the MATLAB Simulink. So, direct voltage is considered to be converted as an alternating voltage by a 35-level inverter after the solar power plant which has the power of 110 MW produce 360 kV of direct voltage. A line which covers 240 km of distance is preferred to transmit electrical power from the A1 point to an A2 point. Due to this, the required mathematical equations are calculated with a circuit analyzing method for the line modeling in the simulation. Experiments on the model are carried out at the MATLAB Simulink after the creation of an energy transmission line. After that, when measurements are made taking into consideration the A2 node; the capacitor voltage, the transformer current, the A2 node current, and the fault current, values are given according to the converted voltage at the frequencies of 100 Hz, 80 Hz, and 50 Hz. The obtained results demonstrate the success of the proposed line system, while power is distributed with eliminated fault at a long distance at different frequencies.

Can, Erol; Sayan, Hasan Huseyin

This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulation for a boost converter switch because the needed voltage is provided for a DC motor. After that, the PID controlling direct current (DC) to a direct current boost converter running the DC motor is implemented at the Matlab Simulink. In addition to that, the only constant source running the DC motor is simulated at the Matlab Simulink. The DC motor operated by the PID controlling converter that has a low input voltage is compared to the DC motor operated by the high constant DC voltage. A low voltage input converter controlling the DC motor has a high performance according to the high constant DC source running the DC motor.

Can, Erol; Sayan, H. Huseyin

In this study, dc-dc boost converter circuit is described as transformer circuit for direct form of energy in the electrical machine driver system of electrical and electronic engineering. First, mathematical equations of the converter circuit are created when circuit switch opened and closed controlling two states. Then, the equations are resolved for common equation so that the state space equation is formed in matrix form. A mathematical model of the converter circuit is performed at the Matlab Simulink.