Sürdürülebilir Kalkınma Amaçları
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- ArticleYalnız künye2026A Cost-Effective Ultra-High-Gain Single-Switch DC–DC Converter with Direct Power Transfer for Low-Voltage PV Applications
Sahin, Yakup; Ozgenel, Mehmet Cihat; Ting, Naim Suleyman
This paper presents a novel cost-effective, nonisolated ultra-high-gain single-switch DC–DC converter (UHGS2C) employing a voltage lift (VL) cell and a direct power transfer (DPT) mechanism, specifically designed for low-voltage photovoltaic (PV) applications. The proposed topology achieves an 8× voltage gain at a duty cycle of 0.5 using only a single active switch, three inductors, three capacitors, and five diodes, thereby reducing component count and control complexity compared with conventional high-gain converters. Through the DPT mechanism, a portion of the input energy is transferred directly to the load during the switch-on interval, thereby reducing the energy processed by the magnetic elements and lowering both switch current stress and capacitor voltage ratings. The steady-state analysis confirms that the maximum capacitor voltage is limited to half of the output voltage (VCmax = VO/2), enabling the use of compact, low–voltage-rated capacitors that improve power density and reduce cost. Both continuous and discontinuous conduction modes (CCM/DCM) are analyzed in detail, and a systematic design procedure, along with a comprehensive power loss model, is provided. To validate the theoretical analysis, a 200-W experimental prototype operating at 25-V input, 200-V output, and 50-kHz switching frequency was implemented. The prototype achieves a peak efficiency of 96.4%, while the closed-loop PI control verifies stable line- and load-regulation performance. Comparative results demonstrate that the proposed UHGS2C provides a favorable trade-off among voltage gain, efficiency, component stress, and compactness, making it a strong candidate for renewable energy applications such as PV systems.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2026Compact and Cost-Efficient Dual-Buck NPC Inverter with Dead-Time Elimination and Shoot-Through Suppression
Sahin, Yakup; Blaabjerg, Frede; Hatas, Hasan; Ting, Naim Suleyman; Bakan, Ahmet Faruk; Ahmed, Md Rishad
Dead-time insertion is the conventional method for preventing shoot-through faults in neutral-point-clamped inverters (NPCIs), but it inevitably degrades output-voltage quality, lowers efficiency, and increases control complexity due to dead-time compensation. This article presents a novel transformer-based dual-buck NPCI (T-DB-NPCI) cell that inherently solves this problem at the topology level. The proposed structure not only eliminates the need for dead-time during normal switching transitions but also provides robust hardware suppression of destructive, long-duration shoot-through faults. The proposed cell is designed to safely withstand forced shoot-through faults of up to 2 μs, ensuring high reliability without requiring complex detection algorithms. The topology features a remarkably compact structure comprising only a single high-frequency transformer and one auxiliary diode, enabling all semiconductor devices to operate at only half the DC-link voltage. Furthermore, the streamlined structure allows for the use of standard sinusoidal pulse width modulation (SPWM), significantly reducing control complexity. Comprehensive results from a 425-W prototype achieving 97.4% peak experimental efficiency confirm excellent performance. A comparative analysis reveals an 8% improvement in power density (683 W/kg) and a 6% cost advantage over its closest counterpart. The T-DB-NPCI topology emerges as a highly promising solution where reliability and simplicity are critical.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2025Design, analysis, and implementation of DC-DC boost converter with new active snubber cell
Gecmez, Hilal Sebnem; Ting, Naim Suleyman; Sahin, Yakup
In this paper, a new active snubber cell for DC-DC boost converters is introduced for the purpose of soft switching. The introduced snubber cell ensures lossless turning-on by zero-voltage transition (ZVT) and turning-off by zero-voltage switching (ZVS) of the main switch. Besides, it enables turning-on by ZVS and turning-off by zero current switching (ZCS) of the main diode. None of the semiconductor power devices are subjected to extra voltage stress, and all of them operate by soft switching (SS). The converter can successfully maintain the SS even under light loads. Furthermore, the proposed converter structure is advantageous in terms of simplicity and low cost. The operating modes and theoretical analysis of the introduced converter are presented and it is validated using a prototype with a 500 W output power and at the 100 kHz switching frequency. Owing to the proposed active snubber cell, the converter efficiency is achieved as 97.2%.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2025Efficient Soft-Switching Snubber Cell Design for PWM DC-DC Boost Converters: Enhanced Load-Independent Performance
Sahin, Yakup; Ting, Naim Suleyman
Soft-switching (SS) boost converters are extensively utilized in applications such as renewable energy systems, electric vehicles, and high-efficiency power supplies, as they offer reduced switching losses and enhanced overall efficiency. Zero-voltage transition (ZVT) snubber cells that used SS operation perform poorly in zero-voltage switching (ZVS) turn-off at light load, although they perform well at heavy load. This study proposes a novel SS snubber cell for the PWM-DC boost converter, ensuring excellent ZVS turn-off performance under all load conditions. The main switch is turned off with ZVS at heavy and light load, so the turn-off performance is independent of the load conditions. In addition, the main switch is switched on with ZVT, and the main diode is switched with SS. The main and auxiliary semiconductor components do not expose additional voltage. In addition, the semiconductor switches are switched on with zero-current switching (ZCS) and switched off with ZVS, whereas the auxiliary diode is switched with SS. The theoretical analysis of the converter is presented, and an experimental study is conducted to demonstrate the analysis. The proposed converter is operated with an output power of 500 W and a switching frequency of 100 kHz.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2025Enhanced soft-switched T-type neutral-point clamped (T-NPC) inverter with reduced component number
Ozgenel, Mehmet Cihat; Ting, Naim Suleyman; Sahin, Yakup
This paper presents an enhanced soft-switched T-type neutral-point clamped inverter featuring a compact active snubber cell that delivers zero-voltage transition turn-on and zero-voltage switching (ZVS) turn-off for the main switches, while auxiliary switches operate with zero-current switching turn-on and ZVS turn-off. Unlike prior designs, four auxiliary-path diodes are eliminated, reducing component count, conduction path length, and reverse-recovery losses, which in turn lowers cost, eases thermal management, and boosts power density. The proposed topology maintains full soft switching (SS) for all active devices without introducing additional voltage or current stress. The theoretical analysis of the inverter is clarified, and the operating modes for steady-state analysis are presented in detail. Experimental validation on a 400 V, 1 kW, and 100 kHz prototype demonstrates consistent SS across load conditions and a peak efficiency of 97.2%. The combination of higher efficiency, structural simplicity, and cost-effectiveness makes the proposed inverter a strong candidate for high-performance, compact T-type applications in renewable energy, and electric drive systems.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2023A novel capacitor-voltage reduced bidirectional PWM DC-DC buck-boost converter for renewable energy battery charge system
Sahin, Yakup; Ting, Naim Suleyman; Yesilyurt, Huseyin
A novel capacitor-voltage reduced bidirectional (CVRB) PWM DC-DC buck-boost converter is presented in this study. Compared to the conventional bidirectional buck-boost converter, the proposed converter has a lower voltage rating filter capacitor. Accordingly, the given converter has a lower cost and higher power density than the conventional buck-boost converter. Additionally, the proposed converter is more efficient due to the direct power transfer feature. Besides, the semiconductor switches have no extra voltage/current stress. The theoretical analysis of the converter is made, and its mathematical analysis is presented. The novel converter is experimentally operated in both the buck and boost modes. The experimental waveforms are shown for both operations. The proposed converter is operated in 100 W output power and 20 kHz switching frequency conditions. The efficiency of the proposed converter is 95.6% for the boost mode operation and 95.1% for the buck mode operation at the nominal output power.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2023Design and Implementation of a Flyback-Assisted Wide-Range Fully Soft-Switched T-Type Inverter
Ting, Naim Suleyman; Sahin, Yakup; Ozgenel, Mehmet Cihat
A novel soft-switched three-level T-type inverter is proposed in this article. The proposed inverter provides turning-on by zero-voltage transition and turning-off by zero-voltage switching (ZVS) for main switches without any voltage or current stresses. The switching energies are transferred to the snubber capacitors, so the turning-off process of the main switches is improved by these snubber capacitors. Besides, the auxiliary switches are turned on by zero-current switching and turned off by ZVS. Furthermore, all snubber diodes are operated by soft-switching (SS), and the proposed SS snubber cell decreases the electromagnetic interference noises. The novel snubber cell has a simple structure, ease of application, common-ground switches, and low-cost features. The theoretical analysis of the inverter is clarified, and the operating modes for steady-state analysis are presented in detail. The experimental results rated 1-kW output power and 100-kHz switching frequency are provided to justify the theoretical analysis. The proposed unique snubber cell can be easily implemented in other three-level inverters, and the practice is demonstrated in the article.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2023Fully soft-switched half-bridge DC–DC converter for hybrid electric vehicle battery charge applications
Yesilyurt, Huseyin; Sahin, Yakup; Ting, Naim Suleyman
This paper proposes a soft-switching (SS) active snubber cell for half-bridge (HB) DC–DC converters, which are utilized in hybrid vehicle battery charge applications. The proposed converter has an advantage over conventional HB DC–DC converters, which suffer from transformer leakage inductance issues. The new snubber cell performs SS operation using the energy stored in the leakage inductance. Thus, the leakage inductance, which creates troubles for HS DC–DC converters, is beneficial to the proposed converter. The proposed SS HB DC–DC converter is compared with the conventional HB DC–DC converter under 100 kHz and 110 W output power operating conditions. The efficiency of the proposed converter is 7.3% and 4.8% higher than the conventional HB converter at light and heavy loads, respectively. The proposed active snubber cell provides complete SS for the main and auxiliary semiconductor switches. The new snubber cell has a basic structure, low-cost, ease of application, and simple control features.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2022A novel zero voltage transition boost converter and artificial neural network-based estimation of converter efficiency
Ting, Naim Suleyman; Aslay, Fulya; Sahin, Yakup
In this paper, a novel zero voltage transition (ZVT) boost converter is proposed, and the overall efficiency of the converter is predicted with an artificial neural network (ANN) model. In the proposed converter, the main switch is turned on by ZVT and turned off by zero voltage switching (ZVS). Also, the other semiconductor elements operate by soft switching (SS). Besides, the proposed snubber cell has the bidirectional direct power transfer feature. The theoretical analyzes of the converter are verified by an prototype having 50 VDC input voltage, 100 VDC output voltage, 250 W output power, and 100 kHz switching frequency. The overall efficiency of the converter in hard switching (HS) condition is increased from 87.2% to 95.4% thanks to proposed snubber cell. Moreover, the efficiency of converter at HS operation is estimated with ANN. For this estimation, 110 efficiency values are obtained based on the different switching frequency and the output power values. When the actual efficiency measurements and the estimation results obtained with the ANN model are compared, it is seen that the results overlap and is obtained very close result to the truth by ANN. Thus, owing to the ANN model, the semiconductor power elements will not need to be operated at high frequencies and overheating, and the damaging to the elements will be prevented. Finally, the efficiency curve measurement of the converter takes long time in the experimental study when it takes highly short time as a few minutes in the estimation with ANN.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2021Zero-voltage switching half-bridge pulse width modulation DC–DC converter with switched capacitor active snubber cell for renewable energy applications
Bodur, Haci; Yesilyurt, Huseyin; Ting, Naim Suleyman; Sahin, Yakup
In this paper, soft switching isolated half-bridge converter with a new active snubber cell that uses switched capacitor for renewable energy applications is proposed. The proposed snubber cell does not consist any magnetic element so that its structure is quite simple. Furthermore, the auxiliary switches in the proposed active snubber cell are exposed to only half of the input voltage. There is no additional voltage and current stress on any semiconductor devices. All semiconductor power devices in the proposed converter are operated by soft switching. The proposed converter is analyzed thoroughly, and the theoretical analyzes are affirmed by an implementation having 300-VDC input, 20-VDC output, 75-W output power, and 150-kHz switching frequency. The overall hard switching efficiency of the converter is increased from 86.4% to 92.9% by aid of the proposed soft switching snubber cell.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2019Design and application of a novel snubber cell for soft switched pwm dc–dc converters
Sahin, Yakup; Ting, Naim Suleyman
This paper introduces a novel active snubber cell for soft switching PWM DC–DC converters. In the proposed converter, the main switch is turned on under zero voltage transition (ZVT) and turned off under zero voltage switching (ZVS). The auxiliary switch and all of the other semiconductors in the converter are turned on and off with soft switching (SS). There is no extra voltage stress on the semiconductor devices. Besides, the proposed converter has simple structure and ease of control due to common ground. In this treatise, the theoretical and mathematical analysis of the proposed converter are presented and the design procedure of converters is also provided. The simulation study at 100 kHz switching frequency and 600 W output power are conducted. The experimental prototype of converter is operated under same conditions. Both the simulation and the experimental prototype exhibits similar performances. Ultimately, the efficiency of the proposed converter is 95.7% at nominal power.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2019Design and implementation of an IBC reduced voltage across output capacitor
Ting, Naim Suleyman; Sahin, Yakup; Yetgin, Halil
Interleaved boost converter (IBC) is equal to two-boost converter operating in parallel. IBCs are more advantageous than conventional boost converters. Input current of the interleaved converter is less fluctuated compared to that of the boost converter. In this paper, a new IBC structure is introduced unlike the conventional IBC structure. In the presented converter, the place of output filter capacitor is changed unlike the conventional IBC and thus, the voltage across the output filter capacitor is reduced about Vi. The proposed IBC performs similar experimental results compared to that of the conventional IBC. Besides, the proposed IBC enables the utilization of an output filter capacitor even with lower voltage, and thus the cost of IBC is reduced. The analysis of operating stages of the presented converter is conducted for D < 50% and D > 50% modes. Finally, an experimental setup of the presented converter is realized along with the parameters of 640 W and 20 kHz.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2018A Novel Soft Switching Passive Snubber Cell for Pulse Width Modulation DC-DC Converters
Sahin, Yakup; Ting, Naim Suleyman
A new soft switching passive snubber cell for pulse width modulation (PWM) DC-DC converters is proposed in this paper. In the new converter, the switch is turned on with zero current switching (ZCS) and is turned off with zero voltage switching (ZVS). Besides, the main diode is turned on and off with ZVS and ZCS, respectively. Thus, the switching losses both of switch and main diode are reduced. In addition, the reverse recovery losses of main diode are significantly minimized. The auxiliary semiconductors in the snubber cell are completely operated with soft switching. The proposed converter has a simple structure, low cost and ease of application. In this study, the detailed theoretical analysis of new converter is made and a 200 W laboratory prototype is implemented. Finally, the theoretical analyses are verified with the experimental results.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2018Soft switching passive snubber cell for family of PWM DC–DC converters
Sahin, Yakup; Ting, Naim Suleyman
In this paper, a novel soft switching passive snubber cell for family of isolated/non-isolated pulse width modulation DC–DC converter is proposed. In this proposed converter, the switch is turned on with zero current switching (ZCS) and is turned off with zero voltage switching (ZVS). Besides, the main diode is turned on and off with ZVS and ZCS, respectively. In addition, the reverse recovery losses of main diode are minimized. The auxiliary diodes in the snubber cell are operated with soft switching. The proposed converter has a simple structure, low cost and ease of application. The detailed theoretical analysis of new converter is made, and a 200-W laboratory prototype is implemented. The theoretical analysis is confirmed with the experimental results. Finally, the proposed passive snubber cell is applied to family of other isolated/non-isolated DC–DC converter in order to provide soft switching.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2018A soft switching with reduced voltage stress ZVT-PWM full-bridge converter
Sahin, Yakup; Ting, Naim Suleyman; Acar, Fatih
This paper introduces a novel active snubber cell for soft switching pulse width modulation DC-DC converters. In the proposed converter, the main switch is turned on under zero voltage transition and turned off under zero voltage switching (ZVS). The auxiliary switch is turned on under zero current switching (ZCS) and turned off under zero current transition. The main diode is turned on under ZVS and turned off under ZCS. All of the other semiconductors in the converter are turned on and off with soft switching. There is no extra voltage stress on the semiconductor devices. Besides, the proposed converter has simple structure and ease of control due to common ground. The detailed theoretical analysis of the proposed converter is presented and also verified with both simulation and experimental study at 100 kHz switching frequency and 600 W output power. Furthermore, the efficiency of the proposed converter is 95.7% at nominal power.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2018Design, analysis and application of high set-up ZVT DC–DC converter with direct power transfer
Sahin, Yakup; Ting, Naim Suleyman
In this paper, a new snubber cell for soft switched high set-up DC–DC converters is introduced. The main switch is turned on by zero-voltage transition and turned off by zero-voltage switching (ZVS). The main diode is turned on by ZVS and turned off by zero-current switching. Besides, all auxiliary semiconductor devices are soft switched. Any semiconductor device does not expose the additional current or voltage stress. The new snubber transfers some of the circulation energy to the output side when it ensures soft switching for main semiconductor devices. Thus, the current stress of auxiliary switch is significantly reduced. Besides, the total efficiency of converter is high due to the direct power transfer feature of new converter. A theoretical and mathematical analysis of the new converter is presented, and also verified with experimental set-up at 500 W and 100 kHz. Finally, the overall efficiency of new converter is 97.4% at nominal output power.
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