A ZVS-PWM Three-Phase Current-Fed Push–Pull DC–DC Converter

Abstract

In this paper, a ZVS-PWM three-phase currentfed push-pull DC-DC converter is proposed. When compared to single-phase topologies, the three-phase DC-DC conversion increases the power density, uses the magnetic core of the transformer more efficiently, reduces the stress on switches and requires smaller filters since the frequency for its design is higher. The proposed converter employs an active clamping technique by connecting the primary side of the transformer to a three-phase full bridge of switches and a clamping capacitor. This circuit allows the energy from the leakage inductances to be reused, increasing the efficiency of the converter. If appropriate parameters are chosen, soft-commutation of the switches (ZVS) can also be achieved. The soft-commutation improves the efficiency even further, allows higher switching frequencies to be used and reduces the electromagnetic interference (EMI) significantly. Applications such as fuel cell systems, transportation and uninterruptable power supplies are some examples that can benefit from the advantages presented by this converter. The theoretical analysis, a design example and experimental results for a prototype implementing this topology are presented. The prototype was designed to process 4 kW at full load with an input voltage of 120 V, an output voltage of 400 V and a switching frequency of 40 kHz.

Naturally Clamped Soft-Switching Current-Fed Three-Phase Bidirectional DC/DC Converter

“…Compared to single-phase topology, three-phase topology offers several obvious benefits [15][16][17][18][19] that make the three-phase topology a better candidate for higher current applications. Several three-phase current-fed dc/dc converters with active-clamping have been proposed including [15][16][17][18]. Parasitic capacitance of the switches and leakage inductances of transformer are utilized to achieved ZVS soft-switching.…”

Steady-State Analysis of a ZVS Bidirectional Isolated Three-Phase DC–DC Converter Using Dual Phase-Shift Control With Variable Duty Cycle

“…The be observed t mum and mini y decreasingly ed to determin oltage, althou g (6) er turns ratio. g d=0.5 and ut voltage bus e following ex (12), th wer factor PF be obtained a nsidering tha wer values oc pectively. Be θ and α ten proximately nu of P o by vary duty cycle, th er values of α seen that the s than that ob ycle is not equ rical, implyin he consequen e power factor that the maxim imum PF poin y.…”

An overview of DC–DC converter topologies for fuel cell-ultracapacitor hybrid distribution system

“…Hence, to increase the power density, increase the transformer utilisation, reduces the stress on switches, and reduces the output filter, a ZVS-PWM three-phase current-fed push-pull dc-dc converter is proposed in Ref. [50]. An active clamping and soft-commutation with ZVS and high efficiency up to 94% can be achieved with this configuration.…”