Multi‐port DC–DC converter for bipolar medium voltage DC micro‐grid applications

Abstract

In this study, a new bipolar DC-DC converter based on the combination of a multi-port dual active bridge and a neutral point clamp topology is proposed. This topology provides the integration of multiple renewable energy sources, with different types and capacities, to a bipolar medium voltage DC micro-grid. The main advantages of the proposed topology are its high power density and the reduced number of switches with respect to the combination of different converters. Moreover, it provides isolation which is crucial for some micro-grid power conditioning converters. The proposed converter is employed for a typical hybrid generation system consisting of a photovoltaic (PV) system, a fuel cell (FC), and a battery (BAT) considering the characteristics of each power generation system like maximum power point tracking of PV, optimum operating region of FC and over-charge/discharge of BAT. In addition, the proposed converter is simulated in different power sharing modes in MATLAB/ Simulink software environment. Eventually, the theoretical and simulation analyses are validated by experimental prototype results.

Isolated and Nonisolated DC-to-DC Converters for Medium-Voltage DC Networks: A Review

“…Multi-terminal direct current (MTDC) networks represent the future of smart grids with different multiple large scale energy sources [71], [113]. That leads to the development of multi-port DC-DC converters (MPCs) to connect these resources.…”

“…That leads to the development of multi-port DC-DC converters (MPCs) to connect these resources. A good example is proposed in [113], which combines two different topologies, NPC and the DAB. This combination can manage the power among three-generation systems, including a PV panel, fuel cell, and battery.…”

Multi‐input high step‐up inverter with soft‐switching capability, applicable in photovoltaic systems

“…Except flyback converters, the proposed DC-DC converter, [23,25,27,32] have the least semiconductors in comparison with other competitors, considering [24,28,29,35,36] with the highest semiconductors count. Note that, high numbers of semiconductors are placed in the secondary side of [35] to suppress their high voltage stress in high power applications. From the passive elements count point of view, [23,27,34] have less passive elements in comparison with the proposed converter.…”

“…However, their output voltage gains are low, and switch stresses are high in higher power ranges. Except flyback converters, the proposed DC–DC converter, [23, 25, 27, 32] have the least semiconductors in comparison with other competitors, considering [24, 28, 29, 35, 36] with the highest semiconductors count. Note that, high numbers of semiconductors are placed in the secondary side of [35] to suppress their high voltage stress in high power applications.…”

“…Furthermore, [27] has more semiconductors. Among the converters of Table 1, [24–26, 28, 32, 35] have more inductors, which make them bulky. In addition, in [28], a four‐wiring transformer and in [29], two transformers are utilised, which increase their sizes.…”