Modulation Scheme for the Bidirectional Operation of the Phase-Shift Full-Bridge Power Converter
TL;DR: In this paper, a modulation technique for the bidirectional operation of the phase-shift full-bridge (PSFB) dc/dc power converter is proposed to overcome the drain voltage overshoot of the isolated boost converter, without additional components other than the ones in a standard PSFB.
Abstract: This paper proposes a novel modulation technique for the bidirectional operation of the phase-shift full-bridge (PSFB) dc/dc power converter. The forward or buck operation of this topology is well known and widely used in medium-to-high-power dc-to-dc converters. In contrast, backward or boost operation is less typical since it exhibits large drain voltage overshoot in devices located at the secondary or current-fed side—a known problem in isolated boost converters. For that reason, other topologies of symmetric configuration are preferred in bidirectional applications. In this work, we propose a modulation technique overcoming the drain voltage overshoot of the isolated boost converter, without additional components other than the ones in a standard PSFB and still achieving full or nearly full ZVS in the primary or voltage-fed side devices along all the load range. The proposed modulation has been tested in a bidirectional 3.3 kW PSFB achieving a 98% of peak efficiency in buck mode (380 V input, 54.5 V output), and a 97.5% in boost mode (51 V input, 400 V output). This demonstrates that the PSFB converter may become a relatively simple and efficient topology for bidirectional dc-to-dc converter applications.
Citations
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TL;DR: In this article , the authors present a state-of-the-art analysis of advanced converter topologies and charging methodology for electric vehicle applications and compare them with the conventional topologies.
Abstract: The rise of greenhouse gas levels in the atmosphere is a severe climate change concern. A significant part, such as CO2 emission, comes from internal combustion engine-driven vehicles, incited the automotive sector to focus more on the sustainable electric transportation system. However, electric vehicles face significant charging time, charging methods, and range anxiety challenges. To overcome these challenges, charging technologies for electric vehicle batteries play an essential role. Many types of electric vehicle charging topologies have been discussed in the literature and implemented in many practical applications. This paper presents a state of art criticism of advanced converter topologies and charging methodology for electric vehicle applications. Apart from the conventional topologies, this manuscript has covered the comparative criticism of the recently proposed EV charging technologies regarding charging methods, control strategies, and power levels. Further, this paper discussed the different onboard chargers with their power factor correction topologies, drawbacks, and required corrections. This manuscript provides the research directions for the academic and industrial communities.
41 citations
TL;DR: An interleaved soft-switching bidirectional dc–dc converter (BDC) with high voltage conversion ratio (VCR) and low voltage stress is proposed for battery charging/discharging applications to achieve high VCR and reduced voltage stresses simultaneously.
Abstract: In this article, an interleaved soft-switching bidirectional dc–dc converter (BDC) with high voltage conversion ratio (VCR) and low voltage stress is proposed for battery charging/discharging applications. A built-in transformer (BT) is integrated into conventional half-bridge BDC and three-level structure to achieve high VCR and reduced voltage stresses simultaneously. The feature of BT is that the balanced magnetic flux exists in the magnetic core, which allows for small size of the magnetic core. The current ripple in the battery side is reduced by adopting the interleaved structure. Moreover, the voltage-matching on both sides of the BT is realized by the adjustment of the duty cycle. As a result, even if the battery voltage changes, the BT always operates under the highest efficiency condition. Besides, by employing phase-shift control, power flow can be regulated monotonously. Soft-switching of all the switches within a wide range of battery voltage is obtained by employing the optimal design. The operational principles, characteristics, and design considerations are analyzed in detail. Experimental results from the BT-BDC prototype of 1-kW, 40–60 to 400 V verify the effectiveness.
12 citations
Cites background from "Modulation Scheme for the Bidirecti..."
...Although isolated BDCs are widely applied in the industrial field [9], there are still many occasions without galvanic isolation, such as battery supplied motor drive system in hybrid electric vehicles or aircraft [10]–[12]....
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TL;DR: In this article , a zero-voltage switching (ZVS) full-bridge converter is proposed to overcome the disadvantages of traditional phase-shifted full-branch (PSFB) converter.
Abstract: In this article, a novel zero-voltage switching (ZVS) full-bridge converter is proposed to overcome the disadvantages of traditional phase-shifted full-bridge (PSFB) converter. In the proposed converter, a half-bridge (HB) converter with center-tap rectifier (CTR) is integrated into the traditional PSFB converter by sharing the lagging-leg switches and output filter. The HB converter operates with full duty cycle to ensure continuous energy transmission and the output voltage is regulated by adjusting the phase-shifted time of full-bridge (FB) converter. The proposed converter has many advantages such as reduced filter requirement, wide ZVS range and low primary circulating current. In addition, the rectifier in the proposed converter is composed of a full-bridge rectifier section and a CTR section. This feature makes the proposed converter well appropriate for the medium output voltage applications. Key operation principle and characteristics are fully discussed in this article. The effectiveness of proposed converter is verified using a 1.2 kW prototype circuit with 280 V input voltage and 60–120 V output voltage.
6 citations
TL;DR: In this article , a direct actual power control (DAPC) scheme based on virtual impedance estimation (VIE) is proposed for the current-fed DAB converters in order to improve the dynamic performance.
Abstract: High dynamic performance is an essential requirement for the dual-active-bridge (DAB) dc/dc converters. As dc voltage sources, they should maintain the desired output voltage instantly under all working conditions. However, the previous literature mainly focus on the dynamic control of the voltage-fed DAB converters, and the existing control schemes for the current-fed DAB converters achieve limited dynamic performance. Aiming at improving the dynamic performance, a direct actual-power control (DAPC) scheme based on virtual impedance estimation (VIE) is proposed for the current-fed DAB converters in this article. The proposed DAPC scheme is based on a parallel structure instead of the series structure of existing control schemes, and it realizes fast dynamic control through combining actual power control with the VIE method. The proposed DAPC scheme can obtain the fastest transient response for the output voltage without voltage overshoot in transient conditions, such as load step change, input voltage fluctuation, and the desired output voltage step change. Besides, a leakage inductor precharging method is integrated into the DAPC scheme to avoid the current mismatching. Finally, the proposed DAPC schemes are compared with two existing control schemes and tested in a scale-down experimental prototype. Experimental results verify the effectiveness of the proposed DAPC scheme.
6 citations
DOI•
TL;DR: In this paper , a direct actual power control (DAPC) scheme based on virtual impedance estimation (VIE) is proposed for the current-fed DAB converters in order to improve the dynamic performance.
Abstract: High dynamic performance is an essential requirement for the dual-active-bridge (DAB) dc/dc converters. As dc voltage sources, they should maintain the desired output voltage instantly under all working conditions. However, the previous literature mainly focus on the dynamic control of the voltage-fed DAB converters, and the existing control schemes for the current-fed DAB converters achieve limited dynamic performance. Aiming at improving the dynamic performance, a direct actual-power control (DAPC) scheme based on virtual impedance estimation (VIE) is proposed for the current-fed DAB converters in this article. The proposed DAPC scheme is based on a parallel structure instead of the series structure of existing control schemes, and it realizes fast dynamic control through combining actual power control with the VIE method. The proposed DAPC scheme can obtain the fastest transient response for the output voltage without voltage overshoot in transient conditions, such as load step change, input voltage fluctuation, and the desired output voltage step change. Besides, a leakage inductor precharging method is integrated into the DAPC scheme to avoid the current mismatching. Finally, the proposed DAPC schemes are compared with two existing control schemes and tested in a scale-down experimental prototype. Experimental results verify the effectiveness of the proposed DAPC scheme.
5 citations
References
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TL;DR: In this article, a comprehensive analysis and experimental results with pulsewidth-modulation (PWM) control of the dual-active-bridge (DAB) topology is presented.
Abstract: The dual-active-bridge (DAB) topology is ideally suited for high-power dc-dc conversion, especially when bidirectional power transfer is required. However, it has the drawback of high circulating currents and hard switching at light loads, if wide variation in input and output is expected. To address these issues, this paper presents a comprehensive analysis and experimental results with pulsewidth-modulation (PWM) control of the DAB. The PWM control is in addition to phase-shift modulation between the two H-bridges. The analysis addresses PWM of one bridge at a time and of both bridges simultaneously. In the latter, five distinct modes arise based on the choice of PWM and load condition. The possibilities are analyzed for optimizing power density and efficiency for low-load operation. Finally, a composite scheme combining single and dual PWM is proposed that extends the soft-switching range down to zero-load condition, reduces rms and peak currents, and results in significant size reduction of the transformer. Experimental results are presented with a 10-kW prototype.
480 citations
TL;DR: In this article, a duty ratio control method is proposed to extend the ZVS operating range when input voltages vary widely, and the three-port dc-dc converters are implemented and tested for a fuel cell and supercapacitor system.
Abstract: Multiport dc-dc converters are particularly interesting for sustainable energy generation systems where diverse sources and storage elements are to be integrated. This paper presents a zero-voltage switching (ZVS) three-port bidirectional dc-dc converter. A simple and effective duty ratio control method is proposed to extend the ZVS operating range when input voltages vary widely. Soft-switching conditions over the full operating range are achievable by adjusting the duty ratio of the voltage applied to the transformer winding in response to the dc voltage variations at the port. Keeping the volt-second product (half-cycle voltage-time integral) equal for all the windings leads to ZVS conditions over the entire operating range. A detailed analysis is provided for both the two-port and the three-port converters. Furthermore, for the three-port converter a dual-PI-loop based control strategy is proposed to achieve constant output voltage, power flow management, and soft-switching. The three-port converter is implemented and tested for a fuel cell and supercapacitor system.
425 citations
TL;DR: In this paper, a circuit-level analytical model that takes MOSFET parasitic capacitances and inductances, circuit stray inductances and reverse current of the freewheeling diode into consideration is given to evaluate the switching characteristics.
Abstract: This paper presents a comprehensive study on the influences of parasitic elements on the MOSFET switching performance. A circuit-level analytical model that takes MOSFET parasitic capacitances and inductances, circuit stray inductances, and reverse current of the freewheeling diode into consideration is given to evaluate the MOSFET switching characteristics. The equations derived for emulating MOSFET switching transients are assessed graphically, which, compared to results obtained merely from simulation or parametric study, can offer better insight into where the changes in switching performance lie when the parasitic elements are varied. The analysis has been successfully substantiated by the experimental results of a 400 V, 6 A test bench. A discussion on the physical meanings behind these parasitic effect phenomena is included. Knowledge about the effects of parasitic elements on the switching behavior serves as an important basis for the design guidelines of fast switching power converters.
396 citations
"Modulation Scheme for the Bidirecti..." refers background in this paper
...A modulation scheme for bidirectional operation of PSFB that overcomes current-fed voltage overshoot has already been reported in [17], achieving zero current switching (ZCS) in the primary-side HV bridge; however, it fails to achieve zero voltage switching (ZVS) which is much more convenient than ZCS for modern HV silicon-based devices (Super Junction MOSFETs) [18]....
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...primary-side HV bridge; however, it fails to achieve zero voltage switching (ZVS) which is much more convenient than ZCS for modern HV silicon-based devices (Super Junction MOSFETs) [18]....
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20 Jun 2004
TL;DR: In this article, a soft-commutating method and control scheme for an isolated boost full bridge converter is proposed to implement dual operation of the well-known soft switching full bridge DC/DC (buck) converter for bi-directional high power applications.
Abstract: A soft-commutating method and control scheme for an isolated boost full bridge converter is proposed in this paper to implement dual operation of the well-known soft switching full bridge DC/DC (buck) converter for bi-directional high power applications. It provides a unique commutation logic to minimize a mismatch between current in the current-fed inductor and current in the leakage inductance of the transformer when commutation takes place, significantly reducing the power rating for a voltage clamping snubber and enabling use of a simple passive clamped snubber. To minimize the mismatch, the method and control scheme utilizes the resonant tank and freewheeling path in the existing full bridge inverter at the voltage-fed side to preset the current in the leakage inductance of the transformer in a resonant manner. Zero-voltage-switching (ZVS) is also achieved for all the switches at the voltage-fed side inverter in boost mode operation. The proposed soft-commutating method is verified through boost mode operation of a 3 kW bidirectional isolated full bridge DC/DC converter developed for fuel cell electric vehicle (EV) applications.
285 citations
TL;DR: This letter shows that in order to determine whether ZVS is provided at a given operating point, the stored charge within the mosfets has to been considered and the condition LI2≥2Qoss has to be fulfilled.
Abstract: Aiming for converters with high efficiency and high power density demands converter topologies with zero-voltage switching (ZVS) capabilities. This letter shows that in order to determine whether ZVS is provided at a given operating point, the stored charge within the mosfet s has to be considered and the condition $L I^2 \geq 2Q_\text{oss} V_\text{DC}$ has to be fulfilled. In the case of incomplete soft switching, nonzero losses occur which are analytically derived and experimentally verified in this letter. Furthermore, the issue of nonideal soft-switching behavior of Si superjunction mosfet s is addressed.
263 citations
"Modulation Scheme for the Bidirecti..." refers background in this paper
...[12] X. Hou, D. Boroyevich, and R. Burgos, “Characterization on latestgeneration SiC MOSFET’s body diode,” in Proc....
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...13 and 14 demonstrate that the prototype achieves soft-switching in those particular scenarios: even if the output capacitance of the devices is not fully discharged when the device turns ON, the remaining losses are not significative for modern HV superjunction MOSFETs [23]....
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...Before the analysis, some assumptions are made: 1) all diodes and switches are ideal; 2) all switches are MOSFETs with intrinsic anti-parallel body diode; 3) all capacitors and inductors are ideal; 4) C1 = C2 = C3 = C4, C5 = C6 = C7 = C8; 5) Lm = ∞....
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...A modulation scheme for bidirectional operation of PSFB that overcomes current-fed voltage overshoot has already been reported in [17], achieving zero current switching (ZCS) in the primary-side HV bridge; however, it fails to achieve zero voltage switching (ZVS) which is much more convenient than ZCS for modern HV silicon-based devices (Super Junction MOSFETs) [18]....
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...[23] M. Kasper, R. M. Burkart, G. Deboy, and J. W. Kolar, “ZVS of power MOSFETs revisited,” IEEE Trans....
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