High efficiency resonant dc/dc converter utilizing a resistance compression network

Abstract

Abstract-This paper presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across a wide range of input voltage, output voltage and power levels. The resistance compression network (RCN) maintains desired current waveforms over a wide range of voltage operating conditions. The use of on/off control in conjunction with narrowband frequency control enables high efficiency to be maintained across a wide range of power levels. The converter implementation provides galvanic isolation and enables large (greater than 1:10) voltage conversion ratios, making the system suitable for large step-up conversion in applications such as distributed photovoltaic converters. Experimental results from a 200 W prototype operating at 500 kHz show that over 95% efficiency is maintained across an input voltage range of 25 V to 40 V with an output voltage of 400 V. It is also shown that the converter operates very efficiently over a wide output voltage range of 250 V to 400 V, and a wide output power range of 20 W to 200 W. These experimental results demonstrate the effectiveness of the proposed design.

Transmission Line Resistance Compression Networks and Applications to Wireless Power Transfer

“…Resistance compression networks (RCNs) are a special class of matching network that provide reduced impedance variation at the rf input as compared to the rectifier inputs. The transmission-line approach in this work is related to one using discrete elements, an idea that has been applied to resonant dc-dc converters [3], [4], [18], [30] and in isolation-port energy recovery in outphasing systems [1]. At microwave frequencies, however, discrete RCN networks have severe limitations relating to the component non-idealities and interconnect parasitics and pose significant manufacturing difficulties (similar to issues arising with lumped power combiners [31], [32]).…”

Design of resistive-input class E resonant rectifiers for variable-power operation

“…Applications for these circuits include very-highfrequency dc-dc converters [1][2][3][4][5][6][7][8], wireless power transfer systems [4], and energy recovery circuits for radio-frequency systems [5,6]. In many of these applications, it is desirable for the rectifier to appear as a resistive load at its ac input port.…”

“…For example, in some very-high-frequency dc-dc converters, proper operation of the inverter portion of the circuit can depend upon maintaining resistive (but possibly variable) loading in the rectifier stage. In still other applications it is desired to have an input impedance that is resistive and approximately constant across operating conditions [5,6]; this can be achieved by combining a set of resonant rectifiers having variable resistive input impedances with a resistance compression network [5,7,8]. In all these systems, however, it is desirable to maintain resistive input impedance of the rectifier as the operating power varies.…”

Design of Class E resonant rectifiers and diode evaluation for VHF power conversion

“…For example, in some very-high-frequency dc-dc converters, proper operation of the inverter portion of the circuit can depend upon maintaining resistive (but possibly variable) loading in the rectifier stage. In still other applications it is desired to have an input impedance that is resistive and approximately constant across operating conditions [5,6]; this can be achieved by combining a set of resonant rectifiers having variable resistive input impedances with a resistance compression network [5,[7][8][9][10]. In all these systems, however, it is desirable to maintain resistive input impedance of the rectifier as the operating power varies.…”

“…Applications for these circuits include very-high-frequency dc-dc converters [1][2][3][4][5][6][7][8], wireless power transfer systems [4,9,10], and energy recovery circuits for radio-frequency systems [5,6]. In many of these applications, it is desirable for the rectifier to appear as a resistive load at its ac input port.…”