Design of High-Efficiency Isolated Bidirectional DC/DC Converter With Single-Input Multiple-Outputs

Abstract

This study mainly develops a high-efficiency isolated bidirectional DC/DC converter (HEIBDC) with a single input and multiple outputs. For the requirement of multiple output voltages with only one single input source, the proposed HEIBDC can achieve the objectives of high-efficiency power conversion and bidirectional power flow. The proposed HEIBDC can be operated at two modes, including the step-down mode and the step-up mode. At the step-down mode, the high-voltage DC bus transmits extra energy to charge the bidirectional input power source. At the step-up mode, it can transmit the energy from the input power source to the high-voltage DC bus for the possible utilization of a later DC/AC inverter, and from the auxiliary source (e.g., a battery module) to supply power for peripheral devices. The proposed HEIBDC uses a coupled inductor to increase the step-up/step-down voltage ratio and adopts an auxiliary inductor to indirectly adjust the voltage of the auxiliary output terminal. Moreover, the utilization of voltage clamping and soft switching in the proposed HEIBDC is helpful for accomplishing the goal of high-efficiency power conversion. In addition, the effectiveness of the proposed HEIBDC is verified by experimental results of a 600W prototype in practical applications. The experimental results reveal that the maximum power conversion efficiency at the step-up mode or the step-down mode is measured to exceed 96%.

Multi-Functional Isolated Three-Port Bidirectional DC/DC Converter for Photovoltaic Systems

“…According to Equation (11), the relationship between duty cycle D, turns ratio n, and the voltage gain (V H /V PV ) of stage one can be obtained, as shown in Figure 11. Among them, the turns ratio n and duty cycle D used in this paper were 4 and 0.33, respectively; therefore, the voltage gain (V H /V PV ) was 12.12.…”

“…Refs. [10,11] presented the most common topology of all isolated converters, which have the advantages of few components, a simple structure, a low cost, and electrical isolation. However, leakage inductance can cause voltage surges to damage components, and therefore they should not be used in high-power applications.…”

“…Ref. [11] presented a forward-flyback converter and a switched capacitor voltage circuit. The topology has the advantages of leakage inductance recovery, ZVS, and high conversion efficiency, and it can effectively improve the problem of large current ripples in traditional forward-flyback converters.…”

Comparative evaluation of a family of isolated Ćuk DC/DC converter with step‐up techniques

“…In other way, different isolates topologies are proposed in the literature. These topologies, include ultra‐high voltage gain [18, 19]; coupled inductors [20, 21]; a transformer [22]; impedance source [23, 24]; soft‐switching [25, 26] conditions; and others. These converters perform well, but the number of switches and other components are high.…”

A Multi-Input-Port Bidirectional DC/DC Converter for DC Microgrid Energy Storage System Applications

“…In recent years, many studies have been conducted on bidirectional DC/DC converters [8,9]. Many battery cells were connected in series to achieve high voltage [10]; however, a charge equalization circuit needs to be introduced to solve the problem of unbalanced battery charging [11].…”