Can, Erol

The integration of solar energy into electronic devices and battery-charging systems is highly valued due to its status as a clean, environmentally friendly power source. To satisfy energy demands while minimising environmental impact, it is essential to adopt efficient, sustainable technologies. This study introduces a multi-output (dual-inductor, single-capacitor) LLC DC-DC converter designed for battery charging applications, capable of independently charging multiple batteries while reducing input voltage fluctuations from photovoltaic (PV) sources. The proposed converter features independently operated coils for each output channel, preventing long-duration short circuits in the inductors. It achieves high-voltage conversion with reduced output voltage variation, offering greater safety and stability compared to conventional converter designs. A key advantage of this system is its ability to deliver different voltage levels across outputs, enabling flexible, simultaneous charging of various batteries and loads. Initially, circuit modelling and system definition are performed to illustrate these benefits. The dual-inductor, dual-output converter is then evaluated under varying temperatures and irradiance levels during the application phase. Results show reduced ripple levels and increased PV output voltage with lower oscillation while maintaining electrical isolation between batteries and loads.

Can, Erol; Sayan, Hasan Hüseyin

Pulse width modulation (PWM) is a very important application in the switch control of inverter and converter circuits in power electronics. In order to make a quality energy conversion, the control of the switches in multi-level inverters is usually done with Sinus Pulse Width Modulation (SPWM). With this PWM structure while creating high-level voltages, unnecessary operation of the switches and sources that make up the lower level is provided at some time intervals. This causes shortening of switch life and power losses due to extra source and switch operation. To solve this problem, a new Fractional Sinus Pulse Width Modulation (FSPWM) development with (Formula presented.) gap on a signal processing method in three steps is presented. In the MATLAB Simulink application, after the development of the FSPWM is presented, the developed Fractional Sinus Pulse Width Modulation (FSPWM) is compared with the traditional SPWM, and it is shown how to mute switches and sources during unnecessary operating times.

Ilgin, Fatih Yavuz

This study investigate statistical properties of Bayes cost, it proposes new group-based detection models for Cognitive Radios (CR) systems using this statistic. In commonly used spectrum sensing applications, multi-user or multi-antenna detection scenario with different optimisation methods are recommended to increase the detection under high SNRs. In this study, the optimum threshold for Covariance Absolute Value detection methods is determined using the Bayesian Cost. Thus, the detection scenario is given for the proposed method and the results are compared with the traditional Covariance Absolute Value method. Simulations based on random communication signals are presented to verify the methods.

Can, Erol

It is very important that the quality of the energy obtained is at a high level while alternating energy is obtained from the direct current energy source. In order to improve the energy quality by reducing the harmonics in the generation of the alternating current, numerous studies have been done on multi-level inverter hardware structures and switching techniques. However, the effect of the slope formed by the difference between the levels in the generated multi-level alternating voltage structure on the resulting harmonic distortions has not been studied so far. So, the paper researches the effects of the inclination between the levels of the alternating voltage generated on load by the inverter. Firstly, after the multi-level inverter structure which can produce four levels of voltage is determined, the operation of this inverter is given in the tabular form. The value of voltage formation gradients (VFG) is calculated according to a generation of multi-level voltages with different amplitude sizes between the levels of the voltage on the R L load after simulation of the system is performed at the Matlab Simulink. After that, obtained load voltages at the simulation are validated in the experiment. The effects of these gradients on the quality of the voltages are determined by measuring harmonic distortions. When the distortion values obtained according to the slope of the alternating voltage structures are analysed, it is seen that the distortion values change significantly as the slope changes. Harmonic distortion caused by VFGs gives the appropriate source values that form voltage levels for the system. Therefore, if the harmonic distortion of the current produced in the load is to be reduced or eliminated, voltage levels of alternating must be generated according to the proposed VFG method.

Can, Erol

After renewable energy generated, a direct current value is converted to a direct current value at another level for a power electronics and power system application that is often considered. In this article, the design and application of a new generation multi-time cascaded DC-DC converter are discussed. The dc-to-dc converter is three-levels, and the switches for each step have a working time and a non-working time. Mathematical models are established depending on the relationship between current and voltage according to the operating and non-operating states of the switches at each stage. After these mathematical models are creating, the new generation multi-timed DC-DC converter is run in Matlab Simulink and simulation results are validated in experimentation. The output voltage and inductor current are observed with a scope. Then, the results from the proposed converter are compared with the results of the traditional converters. The results show the effectiveness of the proposed dc-dc converter.