1,720,972 research outputs found
High Efficient Hybrid Converter Using Center-tapped Clamp Circuit
No full textIn this paper, a hybrid converter combining a phase-shifted full-bridge converter and a resonant half-bridge converter with a new center-tapped clamp circuit is proposed to achieve high efficiency in electric vehicle battery charging systems. The proposed converter has the benefit of half-bridge integrated converters such as the extended zero-voltage-switching range. In addition, by using a new center-tapped clamp circuit, which consists of two diodes and two capacitors, the proposed converter can solve the drawbacks of conventional PSFB converters, such as the substantial circulating current and the severe voltage stress and the significant switching loss in the secondary full-bridge rectifier. With these advantages, the efficiency is considerably increased. In order to validate the feasibility of the proposed converter, a 3.3-kW prototype was tested
Hybrid DC-DC Converter Using Center-Tapped Clamp Circuit in Wide Range of High Output Voltage
No full textIn this paper, a hybrid converter with a new clamp circuit is presented. This hybrid converter has the structure of combining a phase-shifted full-bridge (PSFB)converter with a half-bridge (HB)LLC converter. On the primary side, the lagging-leg of PSFB converter is shared by HB LLC converter. On the secondary side, the full-bridge rectifiers of two converters are connected in series. Due to the series-connected structure on the secondary side, this hybrid converter is suitable for high output voltage applications. In addition, by using a new center-tapped clamp circuit, which consists of two diodes and two capacitors with connected to the center of the transformer, the proposed converter can solve many drawbacks of PSFB converters in wide range of output voltage. Finally, the performance in efficiency, power density, and cost can be improved. In order to validate the feasibility of the proposed converter, a 3.3-kW prototype was tested
A High-Efficiency Power Supply from Magnetic Energy Harvesters
No full textMagnetic energy harvesting is a promising technology for a self-powered sensor, because it rarely depends on the weather condition. In order to increase the power density, maximizing the harvested power is important. In this paper, the analysis for power harvesting according to varying primary current is prevailed, and a new design guideline of primary voltage for maximizing harvested power is suggested. This analysis is distinct in that the effect of magnetizing inductance was taken into the consideration. To confirm the validity of this paper, the experiments were prevailed with a prototype of 4 similar to 7 Arms primary current
A New Full-Bridge Converter with Phase-Shifted Coupled Inductor Rectifier
No full textA conventional phase-shifted full-bridge (PSFB) converter is one of the most promising topologies in high power/high efficiency applications because of its small RMS current, inherent zero-voltage switching (ZVS) capability, and clamped voltage stress of the primary switches. However, when it is designed to satisfy a hold-up time requirement, it operates with small effective duty-ratio in nominal state which causes a large RMS current in the primary side. To solve these problems, secondary-side phase-shifted controlled full-bridge converter with a new coupled inductor rectifier is proposed in this paper. In the nominal state, the proposed rectifier uses synchronous rectification to reduce the conduction loss in the rectifier. And, by shifting the phase of rectifier switches, the proposed converter obtains additional voltage gain during the hold-up state. As a result, the proposed converter can be designed regardless of the hold-up time which results in high efficiency in entire load condition. The effectiveness and feasibility of the proposed converter is verified with 320-400 V input and 56 V/12.8 A output prototype converters
A Phase-Shift Full-Bridge Converter with Novel Voltage Oscillation Clamping Circuit for Electric Vehicle on-Board Charger
No full textIn this paper, a novel clamping circuit is proposed to solve the voltage oscillation problem of the phase-shift full-bridge converter for electric vehicle on-board charger. The proposed clamping circuit, consist of a single capacitor, suppresses the voltage oscillation of the secondary diodes. Besides, this clamping circuit can reduced output filter because it applies the voltage to the output inductor even in the freewheeling period. Therefore, the proposed converter can achieve high efficiency by utilizing the higher performance diode and achieve high power density by the simple clamping circuit and reduced output filter. In the proposed clamping circuit, the amount of voltage oscillation reduction is determined by the ratio of the leakage inductors. Thus, in this paper, the design guideline of leakage inductances is also provided. The feasibility of the proposed converter has been verified with the experimental results under 270-420 VDC output voltage range at 3.3kW
Phase-Shifted Full-Bridge DC-DC Converter With High Efficiency and Reduced Output Filter Using Center-Tapped Clamp Circuit
No full textIn this paper, a phase-shifted full-bridge converter employing a new center-tapped clamp circuit is proposed to achieve high efficiency and reduced output filter in electric- vehicle battery charger applications. By using a simple center- tapped clamp circuit, which consists of two diodes and a capacitor, many limitations in conventional PSFB converters such as circulating current during the freewheeling interval, severe voltage overshoots across the full-bridge rectifier (FBR) on the secondary side, significant reverse-recovery current in the FBR, and the demand of a large output inductor are all solved. With these advantages, high efficiency can be achieved with saving the cost. In order to confirm the effectiveness of the proposed converter, a 3.3-kW prototype was tested
A New Zero-Voltage Switching Three-Level Converter with Reduced Rectifier Voltage Stress
No full textThree-level converters are an attractive structure when the high input voltage is required. Although the voltage stress of switches in the three-level converter becomes half of the input voltage, zero-voltage switching cannot be achieved at light load conditions, which degrades the light load efficiency. This paper proposes a new three-level converter with achieving zero-voltage switching over entire load conditions. In addition, in the proposed converter, the voltage stress of rectifier diodes is low, leading to a reduction of conduction loss in the rectifier circuit. Therefore, by reducing the switching losses in primary switches, light load efficiency increases, and by decreasing the conduction loss in the rectifier circuit, heavy load efficiency is improved. The proposed converter is tested by the prototype with 540-600 VDC input and 750W (48 V/15.625 A) output
ZVS Interleaved Totem-pole Bridgeless PFC Converter with Phase-shifting Control
No full textThis paper proposes an interleaved totempole bridgeless boost power factor correction (PFC) converter employing an additional inductor which has small switching loss. The main problem of conventional interleaved totem-pole bridgeless boost PFC converter is large switching loss due to the hard switching operation. And that problem becomes more serious in high switching frequency operation. In proposed converter, by utilizing the energy of additional inductor, zero-voltage-switching (ZVS) operation of the switches is achieved. Also, by using phase-shifting control between two interleaved PFC units, the flowing current on additional inductor can be controlled and only proper magnitude of current is generated. As a result, the proposed converter has higher efficiency than conventional converter. The feasibility of the proposed converter is confirmed with 50Hz, 230Vrms input and 1.6kW (400V / 4A) output prototype
A strategic control scheme of phase-shift full bridge converter for improving light-load efficiency in server power system
No full textThe phase-shifted full bridge (PSFB) converter is widely used in the middle and high power applications such as a server power system. However, due to the newly required trend for high light-load efficiency, the PSFB converter has a limitation for light-load efficiency because of a large circulating current, core losses of the transformer and inductors, and the insufficiency ZVS energy of lagging-leg switches. To achieve high light-load efficiency in PSFB converter, the circulating current in the freewheeling mode and the core loss should be reduced. Therefore, this paper proposes the strategic control scheme employing the control scheme of the two-switch forward (TSF) converter. In addition, by applying the additional one gate signal and the expanded dead-time, the switching loss can be significantly reduced. To verify the proposed method, the prototype converter with 750W (12V/62.5A) is built and tested
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