New soft‐switched high gain three‐port DC–DC converter with coupled inductors

Abstract

In this study, a new high step-up non-isolated three-port DC-DC converter is proposed. A bidirectional buck-boost converter is used to interface photovoltaic battery and non-isolated load port. Compared to the other three-port converters, the presented topology has fewer component counts, which is the main merit of the proposed converter. The output voltage of the converter can be increased by using a three winding coupled inductor, a diode and a capacitor. Furthermore, since both main switches are turned on with zero voltage switching, switching losses is reduced and the efficiency of the converter is improved. Maximum power point tracking and maintaining the output voltage at a suitable level during the charging and discharging of the battery can be achieved by a simple controller. Moreover, according to the load power demand, three power flow paths will occur. The operation principle will be described in detail for three modes. Finally, the experiments with 400 W, 100 W, 40 V/400 V are implemented to verify the effectiveness of the converter.

Design, analysis and implementation of a new three‐port DC‐DC converter with bidirectional capability

“…As it is clear, the efficiency of the proposed converter in the first to fourth scenarios varies between 91.7–95%, which is higher than the efficiency of the converters in [16, 17, 19, 27]. Furthermore, the proposed converter efficiency is almost equal to the efficiency of the converters in [15, 18, 25, 26]. As the main results of the comparisons, the proposed converter contains positive points in terms of the main quality factors.…”

“…Another important advantage of the proposed structure is the simultaneous transfer of power from input sources, which can be seen in other structures in the table except for the converter in [22, 24, 27]. In the proposed converter, the energy storage device can be recharged by another source, a feature that can also be seen in the converters of [19, 22–25, 27]. The number of components used in the proposed structure is the same as the number of components in the structure in [18, 19, 26].…”

“…The number of components used in the proposed structure is the same as the number of components in the structure in [18, 19, 26]. The structures of [17, 28] use more components and the structures of [15, 16, 22–25, 27] use fewer components than the proposed structure. PVS of the switches and diodes is another factor that should be compared between the structures of Table 3 To have a better comparison between the proposed converter and the converters in literature in terms of PVS, it is supposed that all the converters have the same conditions ( V 1 = 30 V, V b = 24 V, V o = 96 V).…”

“…The diodes of the other structures such as D 3 in [19] and D 5 in [24] experience the PVS equal to V o . Furthermore, the PVS on diode D d in [25] and D 1 in [26] is higher than the proposed converter and these diodes must endure the voltage stress more than V o .…”

“…Another drawback of this converter is its inability to simultaneous power transfer of the input sources. The couple‐inductor‐based three‐port DC‐DC converter in [25] has high voltage gain, however, the power flow direction is unidirectional. Furthermore, the two inputs have no common grounding.…”