Browsing by Author "Şehirli E."

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Comparison of a single phase linear and a buck-boost led driver
(2015-01-01) Şehirli E.; Altınay M.; Cakır B.
This paper presents a comparison of LED driver topologies that include linear and buck-boost converters. Both topologies are connected to grid over a single-phase diode rectifier and designed for 8 W power. Further, buck-boost converters work on a discontinuous conduction mode (DCM) with 63 kHz switching frequency. Finally, power factor and total harmonic distortion (THD) of current and voltage, power LED voltage and current are shown for both topologies over implementations, and a comparison is made. Furthermore, voltage-current characteristic, current and voltage- illuminance characteristics are derived.
Comparison of Average Current Controlled PFC SEPIC and CUK Converter Feeding Current Controlled SRM
(2022-10-29) Şehirli E.; Çetinceviz Y.
In this paper, current control of 6/4 switched reluctance motor (SRM) fed by both power factor correction (PFC) SEPIC and CUK converter is realised and asymmetric bridge converter is used to drive SRM. Furthermore, SEPIC and CUK DC-DC converters are connected in series to diode bridge rectifier in order to build PFC converters. Average current control of PFC converters is carried out by PI algorithm and both converters are operated at continuous conduction mode (CCM). Besides, switching frequency of PFC and asymmetric bridge converters is 62, 9 kHz with 5750 W power. Studies are conducted by using MATLAB/Simulink software. Total harmonic distortions (THD)s of grid current, grid power factor (PF) and output voltages of the converters are compared. Also, THDs of grid current of each converter are compared by IEEE 519-2014 standard. In addition, current waveform and flux of SRM phases are shown. It is validated by simulations that PFC CUK converter gives better result with 9.08% THD, 0.998 PF than PFC SEPIC converter having 9.61% THD and 0.997 PF. Furthermore, both converters provide the limit defined by standards.
Comparison of DC-DC SEPIC, cuk and flyback converters based LED drivers
(2020-01-01) Şehirli E.; Sehirli, E
This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.
Comparison of DC-DC SEPIC, cuk and flyback converters based LED drivers
(2020-01-01) Şehirli E.
This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.
Comparison of single phase buck-boost and sepic LED driver
(2017-01-01) Şehirli E.; Altınay M.; Üstün Ö.; Çakır B.
This paper presents the comparison of LED driver topologies that include buck-boost and SEPIC converters. Both topologies are connected to grid over single phase diode rectifier and designed for 8W power. Furthermore, buck-boost and SEPIC converters operate with 63 kHz switching frequency and inductors of SEPIC are wounded as coupled. By means of the implementations, power factor (PF) and total harmonic distortion (THD) of current and voltage, power LED voltage and current are shown for both topologies. Comparison is also made between IEC61000-3-2 standard, buck-boost and SEPIC converters. Besides, electrical circuit model of power LED is derived by using its current-voltage characteristic.
Comparison of the input filter effect to PV panel by SEPIC MPPT converter
(2023-09-01) Şehirli E.
PV panel with front end converter for MPPT purpose is always employed for solar energy. The current that front end converter draws from PV panel are generally includes ripple regarding to operation mode of the converter and the type of converter. Such current ripple when it has higher magnitude is so harmful for the PV panel, it either shortened lifetime or results faults on PV panel. To overcome such drawbacks, input filter must be used with front end converter for PV panel connection. Although, in the literature, there are a few types of input filter, the effect of the filter and input current ripple and current noises are not compared for PV panel integration. The original contribution of the study is the analysis of input filter types for PV panel integration. As an input filter, LCL, LCL with damping, LC, C filters are used, and their effects are compared for PV panel. In addition, as a front-end converter SEPIC converter is chosen because of having lower or higher output voltage regarding to input voltage. Besides, using LCL based filters as input filters of SEPIC converter are another contribution of the paper. By means of the applications with up to 15 W SEPIC converter and simulations with DC source and PV panel, it is shown that LC filter ensures better results using DC source by applications regarding current ripple and noise level. However, C filter is better for PV panel by simulations than DC source, it is because PV panel exhibits current source character, and LC filter has lower current ripple. Also with PV source, LCL with damping filter transfers higher energy to the load than the others. Furthermore, LCL type filter reduces inductor by 35% and capacitor by 4.7 times in total. Moreover, LCL filter has higher efficiency with 88% than others in the applications and lower ripple for simulations with DC source.
Comparison of the input filter effect to PV panel by SEPIC MPPT converter
(2023-09-01) Şehirli E.
PV panel with front end converter for MPPT purpose is always employed for solar energy. The current that front end converter draws from PV panel are generally includes ripple regarding to operation mode of the converter and the type of converter. Such current ripple when it has higher magnitude is so harmful for the PV panel, it either shortened lifetime or results faults on PV panel. To overcome such drawbacks, input filter must be used with front end converter for PV panel connection. Although, in the literature, there are a few types of input filter, the effect of the filter and input current ripple and current noises are not compared for PV panel integration. The original contribution of the study is the analysis of input filter types for PV panel integration. As an input filter, LCL, LCL with damping, LC, C filters are used, and their effects are compared for PV panel. In addition, as a front-end converter SEPIC converter is chosen because of having lower or higher output voltage regarding to input voltage. Besides, using LCL based filters as input filters of SEPIC converter are another contribution of the paper. By means of the applications with up to 15 W SEPIC converter and simulations with DC source and PV panel, it is shown that LC filter ensures better results using DC source by applications regarding current ripple and noise level. However, C filter is better for PV panel by simulations than DC source, it is because PV panel exhibits current source character, and LC filter has lower current ripple. Also with PV source, LCL with damping filter transfers higher energy to the load than the others. Furthermore, LCL type filter reduces inductor by 35% and capacitor by 4.7 times in total. Moreover, LCL filter has higher efficiency with 88% than others in the applications and lower ripple for simulations with DC source.
Control of LCL filter based Voltage source converter
(2010-12-27) Şehirli E.; Altinay M.
In this paper, the control of Voltage source converter which consists of six IGBT power switches is realized. Grid connection of VSC is provided through LCL filter and sinusoidal pulse width modulation (SPWM) technique which has 9 kHz switching frequency, is used for switching. Three different way of control including a - b - c, d - q and input - output linearization nonlinear control, are analyzed and achieved with simulations in Matlab/Simulink. The effects of control methods to the grid and dc - link are examined. © 2010 IEEE.
Current controlled SRM fed by three-phase voltage source converter
(2015-11-30) Şehirli E.; Kuyumcu F.; Çakir B.
In this paper, simulation of current controlled switched reluctance machine (SRM) which has 6 stator and 4 rotor poles is realized. Furthermore, SRM machine is fed by three phase voltage source converter (VSC) which has six IGBT power switches. The reason of using controlled rectifier is to have higher power factor and also less current harmonics on grid. The current control algorithm of SRM machine is both hysteresis and PI structures. Besides, VSC is controlled by input-output linearization nonlinear control algorithm. Simulations are carried out with Matlab/Simulink. By the simulations, power factor and currents harmonic of grid, current, flux and torque of SRM are presented.
Examining the Design of Different Types of DM EMI Filters and Their Effect on EMI Noise and Control Characteristics for Cuk DC-DC Converter
(2023-01-01) Şehirli E.; Rosas-Caro J.C.
In this paper, DM EMI filters including LC, LC with damping, and Pi and LCL filters are designed for DC-DC Cuk converter operated in BCM. Although, DM EMI is so important for any power converter, the effect of DM filter is not investigated in detail in literature with respect to control characteristics and DM noise reduction. The main contribution of this paper is comparisons of DM EMI filter topologies regarding control characteristics and EMI noise reduction which is not presented in the literature. Another contribution is to give a practical design methodology for EMI filter design avoiding complex mathematical procedures. Besides, the paper designs an LCL filter, popular for inverter applications, for Cuk converter that is not introduced in the literature. Examining the filter effect on the converter from the control point of view is a very complicated issue because a linearized model of the converter which is naturally nonlinear should be obtained. To do so, the converter’s small signal analysis must be derived. Therefore, for examining the effect of filters, a small signal analysis of the Cuk converter is made through an average state-space model. After that, transfer functions of each filter topology are obtained. Lastly, the entire transfer functions of the system using both the Cuk converter and each filter are acquired, separately. By using the transfer functions of overall systems, the effect of each filter topology is investigated by root locus and bode plots. Moreover, experimental verification of all filters is realized over a 15 W Cuk converter with a 25 kHz switching frequency. It is validated by applications that the LCL filter provides better control characteristics on the Cuk converter, the total inductor value is reduced by 30% and the total capacitor value is reduced by 25% compared to other filters. However, with respect to DM noise Pi and LC filters give better results.
Examining the impacts of DM filters to PFC isolated Ćuk converter for DCM operation by comparing Si and SiC MOSFET
(2023-12-01) Şehirli E.
Examining impacts of differential mode (DM) filter topologies covering pi, LC with damping, LC, LCL filter through isolated Ćuk single phase PFC converter is realized in this paper regarding to power factor, THD and efficiency. Application of PFC isolated Ćuk converter is conducted with 42 kHz switching frequency and 50 W power. Each filter is modeled, designed, and applied experimentally via isolated PFC Ćuk converter. Average model derivation based on state-space, for DCM operation of input side inductor of isolated PFC Ćuk converter that is not introduced in literature is the main contribution of the paper. Second main contribution is to analyze filter types by linear methods for the transfer functions cascading the converter and filter transfer functions, which is not presented for PFC converters. It is also presented that solely LCL filter which is not analyzed for PFC converters in detail in literature, does not give desired results. So, increasing the effectivity of LCL filter, new filter structure LCL with parallel C filter is proposed and modeled in this paper. Thanks to the applications, presented results of LCL with parallel C filter is better than others with 4.9% current THD and ‘1’ power factor. Proposed LCL filter ensures 45% reduction of total inductor value, comparing to LC filter. Besides, LCL with C filter provides better control characteristics with maximum allowable gain for stability as 0.7585 higher than other topologies. Moreover, practical design methodology of filter types avoiding complex mathematical procedure is given in this paper. Applications with each filters provide THD requirements, obtained 4.9% as a best value, lower than IEC61000-3-2 standard. Maximum percentage improvement comparing to the IEC61000-3-2 is 27.5% for third harmonic. Furthermore, SiC and Si Mosfets are employed separately in the converter and compared by using each DM filters regarding to power factor, THD, efficiency through applications. As a result, better efficiency with SiC Mosfet as 83% and better THD with Si Mosfet as 4.9% are conducted.
Examining the impacts of DM filters to PFC isolated Ćuk converter for DCM operation by comparing Si and SiC MOSFET.
(2023-03-23T00:00:00Z) Şehirli, Erdal
Examining impacts of differential mode (DM) filter topologies covering pi, LC with damping, LC, LCL filter through isolated Ćuk single phase PFC converter is realized in this paper regarding to power factor, THD and efficiency. Application of PFC isolated Ćuk converter is conducted with 42 kHz switching frequency and 50 W power. Each filter is modeled, designed, and applied experimentally via isolated PFC Ćuk converter. Average model derivation based on state-space, for DCM operation of input side inductor of isolated PFC Ćuk converter that is not introduced in literature is the main contribution of the paper. Second main contribution is to analyze filter types by linear methods for the transfer functions cascading the converter and filter transfer functions, which is not presented for PFC converters. It is also presented that solely LCL filter which is not analyzed for PFC converters in detail in literature, does not give desired results. So, increasing the effectivity of LCL filter, new filter structure LCL with parallel C filter is proposed and modeled in this paper. Thanks to the applications, presented results of LCL with parallel C filter is better than others with 4.9% current THD and '1' power factor. Proposed LCL filter ensures 45% reduction of total inductor value, comparing to LC filter. Besides, LCL with C filter provides better control characteristics with maximum allowable gain for stability as 0.7585 higher than other topologies. Moreover, practical design methodology of filter types avoiding complex mathematical procedure is given in this paper. Applications with each filters provide THD requirements, obtained 4.9% as a best value, lower than IEC61000-3-2 standard. Maximum percentage improvement comparing to the IEC61000-3-2 is 27.5% for third harmonic. Furthermore, SiC and Si Mosfets are employed separately in the converter and compared by using each DM filters regarding to power factor, THD, efficiency through applications. As a result, better efficiency with SiC Mosfet as 83% and better THD with Si Mosfet as 4.9% are conducted.
Input - Output linearization control of three - Phase voltage source PWM rectifier using L and LCL filter
(2010-12-01) Şehirli E.; Altinay M.
In this paper, simulations of three - phase voltage source rectifier using L and LCL filter under input - output linearization nonlinear control, are realized. The control algorithm requires transformations between a-b-c and d-q frames. A bridge rectifier having six IGBT power switches has been employed. For switching, compared triangular wave sinusoidal pulse width modulation (SPWM) technique has been utilized and switching frequency is adjusted to 9 kHz. Simulations are carried out with Matlab/Simulink. A major advantage of using LCL filter compared with the L filter which is the attenuation of harmonics caused by the PWM rectifier, is showed by the simulations. The feature of attenuation can be achieved only if the LCL filter properly damped, in this paper the damping process is carried out with a resistor connected series to filter capacitor. The effects of using L and LCL filter on unity power factor, line currents harmonic distortions and dc - link voltage are presented by the simulations.
Simulation of three-phase voltage source pulse width modulated (PWM) LCL filtered rectifier based on input-output linearization nonlinear control
(2010-08-24) Şehirli E.; Altinay M.
Control of three - phase voltage source pulse width modulation (PWM) LCL filtered rectifier based on input - output linearization nonlinear control is realized. This control algorithm needs to transformation between a - b - c and d - q coordinates. In this paper, grid connection of rectifier which consists of six IGBT power switches, is provided through LCL filter and sinusoidal pulse width modulation (SPWM) technique which has 9 kHz switching frequency, is used for switching. All simulations are carried out with Matlab/Simulink. By the simulation results, line currents' harmonic distortions, and dc - link voltage and the obtaining of unity power factor are shown under load and reference changes. ©2010 IEEE.
WPT Charging System with Average Current Controlled PFC Sepic Converter
(2023-01-01) Oruçož U.; Şehirli E.