Influence of the Rectifier’s Output Capacitance on the ZVS Transition in Asymmetrical Half-Bridge PWM Converters

B. Kohlhepp,M. Barwig,T. Duerbaum 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

High sales quantities and an ongoing miniaturization of notebook power supplies require an improvement of their efficiency. In order to achieve a high power density, a high switching frequency in combination with low losses is necessary. The asymmetrical half-bridge PWM converter fits perfect for these requirements, as it allows zero voltage switching (ZVS) for the half-bridge MOSFETs, which is necessary for an efficient design. Furthermore, high efficiency requires the use of a synchronous rectifier. Unfortunately, measurements on a test setup reveal, that the parasitic output capacitance of the rectifier has a significant influence on the ZVS transition. This is due to the comparably very large output capacitance accompanied with low ohmic MOSFETs. For this reason, the paper examines the ZVS process of the input half-bridge considering the rectifier’s parasitic output capacitance. Furthermore, the required dead time of the half-bridge is predicted, taking the parasitic capacitance into account.

A New Half-bridge Resonant Inverter with Load-Freewheeling Modes

Jae-Eul Yeon,Kyu-Min Cho,Hee-Jun Kim 대한전기학회 2007 Journal of Electrical Engineering & Technology Vol.2 No.2

This paper presents a new circuit topology and its digital control scheme for a half-bridge resonant inverter. As the proposed half-bridge inverter can be operated in load-freewheeling modes, the pulse-width modulation (PWM) method can be used for the output power control. The proposed half-bridge inverter is based on the resonant frequency-tracking algorithm with the goal of maintaining the unity of the output displacement factor of the load impedance even in varying conditions. In this paper, the operation principle, electrical characteristics, and detailed digital control scheme of the proposed half-bridge resonant inverter are described. The experimental results of the prototype experimental setup to verify the validity of the proposed half-bridge inverter are presented and discussed.

Impact effect analysis for hangers of half-through arch bridge by vehicle-bridge coupling

Shao, Yuan,Sun, Zong-Guang,Chen, Yi-Fei,Li, Huan-Lan Techno-Press 2015 Structural monitoring and maintenance Vol.2 No.1

Among the destruction instances of half-through arch bridges, the shorter hangers are more likely to be ruined. For a thorough investigation of the hanger system durability, we have studied vehicle impact effect on hangers with vehicle-bridge coupling method for a half-through concrete-filled-steel-tube arch bridge. A numerical method has been applied to simulate the variation of dynamic internal force (stress) in hangers under different vehicle speeds and road surface roughness. The characteristics and differences in impact effect among hangers with different length (position) are compared. The impact effect is further analyzed comprehensively based on the vehicle speed distribution model. Our results show that the dynamic internal force induced by moving vehicles inside the shorter hangers is significantly greater than that inside the longer ones. The largest difference of dynamic internal force among the hangers could be as high as 28%. Our results well explained a common phenomenon in several hanger damage accidents occurred in China. This work forms a basis for hanger system's fatigue analysis and service life evaluation. It also provides a reference to the design, management, maintenance, monitoring, and evaluation for this kind of bridge.

Operation Characteristic Analysis of an Asymmetrical Half-Bridge Converter with Half-Wave Rectifier

Yerin Lee,Jungho Jeon,Paul Jang 전력전자학회 2023 ICPE(ISPE)논문집 Vol.2023 No.-

Generally, when designing a symmetrical half-bridge converter, the rectifier on the secondary side is composed of a full-bridge rectifier or a center-tap rectifier to take advantage of the full-wave rectifier (FWR). However, when driving with asymmetrical PWM, the benefit of full-wave rectification due to symmetric operation is lost, so a half-wave rectifier (HWR) can be introduced to cope with low-voltage and high-current applications. Furthermore, if an HWR is used with an asymmetrical half-bridge converter (AHBC), the soft switching characteristics of the AHBC can be improved while maintaining appropriate conduction loss. It is because the transformer current has a negative average with the reduced duty cycle loss due to the operation characteristics of HWR. Accordingly, this study examines the superiority of an AHBC with HWR in an efficiency aspect compared to the case of using FWR through the operation characteristic analysis. The validity of the analysis is verified through experiments with a 360-W prototype.

A New Zero-Voltage Switching Half-Bridge Converter with Reduced Rectifier Voltage Ringing

Yu-Ri Lim,Jun-Ho Kim,Jae-Kuk Kim,Gun-Woo Moon 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

Symmetric half-bridge (SHB) converter has been widely used in PC power supply application since it has no DC offset of magnetizing current and it has symmetric device stress. However, it is difficult for SHB converter to get high efficiency due to significant switching loss. To solve this problem, a variety of Zero-Voltage Switching (ZVS) half-bridge converters have been proposed including an asymmetric half-bridge (AHB) converter. They can reduce switching loss with ZVS. However, ZVS half-bridge converters have serious voltage oscillation problem across the secondary rectifier, which would require the snubber circuit. This oscillation is increasingly severe when large resonant inductance is used for wide ZVS range. The proposed converter solves this problem by separating resonant inductance for ZVS from resonance with the rectifier junction capacitance. It reduces energy dissipation on snubber and decreases conduction loss on rectifier. In addition, it has wide ZVS range with series-connection of main switches. Operational principle and analysis of the proposed converter are presented and confirmed by experimental results of a 240W prototype.

Research on An Interleaved Phase-Shift Half-Bridge LLC Resonant Converter

Shu-Po Wang,Min-Rui Hong,Ping-Tsang Wu,Ching-Chun Chuang,Shiue-Der Lu 전력전자학회 2023 ICPE(ISPE)논문집 Vol.2023 No.-

This paper presents the analysis and simulation for a novel high-power density electric vehicle dc-dc converter. In this paper, a novel interleaved phase-shift half-bridge converter that mainly comprises two modules of a half-bridge converter and a double full-bridge rectifier is proposed. In the case of interfacing the high-voltage battery module, the isolated DC/DC converter is used to control the voltage at the input of the battery according to the battery terminal voltage and optimize the efficiency of the dc-dc converter in a wider range of operating voltage. It operates as a voltage doubler to achieve an output voltage of 450V for the charging of a high-voltage battery. The isolated dc-dc converter is operated as an LLC resonant converter owing to its advantages of simple control and soft switching operation. This converter not only has a wide range of zero-voltage- switching (ZVS) turn-on of power switches on the primary side of the transformer but also has a zero-current-switching (ZCS) turn-off of rectifier diode on the secondary side of the transformer. The proposed converter can achieve the output voltage range of 250-450V by adapting the phase shift between the two square waves. The two LLC half-bridge resonant converters are connected in parallel, and it’s operated at a fixed frequency and constant duty cycle. The simplified control strategy in the proposed converter can be achieved since the switching frequency of the converter operates at the resonant point. Finally, a 3.4kW design prototype with 400V input voltage and the 250-450V output voltage is simulated to verify the effectiveness of the phase-shift mode control method.

SOI radiation‑hardened 300 V half‑bridge date driver IC design with high dv/dt noise immunity

Yuexin Gao,Xiaowu Cai,Zhengsheng Han,Yun Tang,Liqiang Ding,Ruirui Xia,Mali Gao,Fazhan Zhao 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.5

Noise immunity is a critical index of high-voltage half-bridge gate driver integrated circuits (IC). Various noise cancelation technologies have been proposed to improve dv/dt noise immunity with sacrifices in terms of area and propagation delay time. Besides, when it is applied to an inductive load, the half-bridge driver is vulnerable to negative surges at the VS terminal, which is the offset ground of the high-side channel. A 300 V half-bridge gate driver IC with noise rejection module is designed in this paper. The noise immunity can be improved to 87.5 V/ns. The VS negative swing region can be extended to − 5.1 V. In addition, the proposed driver IC can work normally at a working frequency of 500 kHz and the delay matching time between the high-side and the low-side is less than 4 ns. The propagation delay time of the high-side channel is measured at 71.6 ns. Furthermore, gamma ray irradiation experimental results show that the proposed structure presents a good radiation tolerance of 100 krad (Si). The presented half-bridge gate driver IC is fabricated with the silicon-on-insulator (SOI) bipolar-CMOS-DMOS (BCD) process, which occupied an area of 1.86 mm2.

A New Half-bridge Resonant Inverter with Load-Freewheeling Modes

Yeon, Jae-Eul,Cho, Kyu-Min,Kim, Hee-Jun The Korean Institute of Electrical Engineers 2007 Journal of Electrical Engineering & Technology Vol.2 No.2

This paper presents a new circuit topology and its digital control scheme for a half-bridge resonant inverter. As the proposed half-bridge inverter can be operated in load-freewheeling modes, the pulse-width modulation (PWM) method can be used for the output power control. The proposed half-bridge inverter is based on the resonant frequency-tracking algorithm with the goal of maintaining the unity of the output displacement factor of the load impedance even in varying conditions. In this paper, the operation principle, electrical characteristics, and detailed digital control scheme of the proposed half-bridge resonant inverter are described. The experimental results of the prototype experimental setup to verify the validity of the proposed half-bridge inverter are presented and discussed.

Integrated Asymmetrical Half-Bridge Zeta (AHBZ) Converter for DC/DC Stage of LED Driver With Wide Output Voltage Range and Low Output Current

Jae-Il Baek,Jae-Kuk Kim,Jae-Bum Lee,Han-Shin Youn,Gun-Woo Moon IEEE 2015 IEEE transactions on industrial electronics Vol.62 No.12

<P>The conventional half-bridge converter for a dc/dc stage in wide-output-voltage and constant-output-current applications such as LED drivers is limited in achieving high efficiency because it is difficult to be designed optimally. To overcome this limitation, an integrated asymmetrical half-bridge zeta converter is proposed for high efficiency in the overall output voltage range. The proposed converter can be simply implemented by replacing a snubber diode with a switch. The proposed converter operates similar to the asymmetrical half-bridge converter by turning off the switch in the low-output-voltage region, which enables it to have a small dc-offset current in the transformer. In the high-output-voltage region, the proposed converter operates similar to the half-bridge zeta converter by turning on the switch, which has small transformer core loss. Therefore, the proposed converter can achieve high efficiency over the entire output voltage range compared with the conventional converters. The validity of the proposed converter is confirmed by experimental results from a prototype with 400-V input and 90-180-W/3-A output.</P>

HVDC 병렬 하프브리지 서브모듈에 대한 고장나무기반의 신뢰성 분석

강필순(Feel-soon Kang),송성근(Sung-Geun Song) 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.4

HVDC 시스템에서 풀-브리지 서브 모듈 구조는 하프브리지 서브 모듈에 비해 부품 수가 증가하지만 100 % 여유율 확보가 가능하여 고장률을 크게 줄일 수 있다. 그러나 풀-브리지 서브 모듈은 여유율 보장과 암(arm) 단락 방지를 위한 데드 타임(dead-time)을 확보하기 위해 복잡한 제어 알고리즘이 필요하다. 이 문제를 해결하기 위해 풀-브리지 서브 모듈과 동일한 부품 수와 100 % 여유율을 갖는 병렬 하프브리지 구성의 고장률을 분석한다. 기존의 부품 고장 분석에 고장나무분석 방법을 적용하여 서브 모듈의 동작 위험을 반영함으로써 서브 모듈의 수명주기를 보다 정확하게 예측할 수 있다. 병렬 하프브리지 서브모듈의 타당성 검증을 위해 FTA 기반 분석 방법과 기존의 PCA 기반 방법으로 분석된 고장률을 비교한다. In HVDC systems, the full-bridge submodule increases the number of components compared to the half-bridge submodule, but the failure-rate can be reduced by securing 100 % redundancy. However, full-bridge submodules require more complex control algorithms to ensure the redundancy and to prevent arm-short with sufficient dead-time. To solve this problem, we analyse the failure-rate of the paralleled half-bridge configuration with the same number of components and 100 % redundancy as the full-bridge submodule. The fault tree analysis (FTA) method is applied to the conventional part failure analysis to reflect the operation risk of the submodule, thereby predicting the life-cycle of the submodule more accurately. To verify the validity, the failure-rate results of the proposed FTA based analysis method are compared with the failure rate obtained by the part failure method.