DC–DC Converters for Bipolar Microgrid Voltage Balancing: A Comprehensive Review of Architectures and Topologies

Abstract

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DC Microgrids: Benefits, Architectures, Perspectives and Challenges

“…References Unipolar configuration [45][46][47][48][49][50][51] Bipolar configuration [45][46][47][52][53][54][55][56][57][58][59] Through the comparison of both configurations, the bipolar DC microgrid presented several advantages, such as a higher number of voltage levels (two instead of one), increased efficiency and a power supply with increased quality [17]. Another important feature is related to reliability, which is higher in the bipolar architecture since, in the case of having a fault in one of the wires, the load can be supplied by the other two healthy lines [17][18][19].…”

“…Usually, generators such as PV use a DC/DC converter that will only connect to a single pole, which will contribute in this way to voltage unbalance. However, there are several strategies that can be used to attenuate or eliminate that unbalance [47]. A summary of the DC microgrid configurations and the corresponding relevant references associated with each of the structures is presented in Table 2.…”

“…Usually, generators such as PV use a DC/DC converter that will only connect to a single pole, which will contribute in this way to voltage unbalance. However, there are several strategies that can be used to attenuate or eliminate that unbalance [47].…”

“…A summary of the DC microgrid topologies and corresponding relevant references associated with each of the structures is presented in Table 1. On the other hand, regarding the configurations, the main ones that have been used, tested and studied are the following ones [45][46][47]:…”

A new soft‐switching high gain DC/DC converter with bipolar outputs

“…It has a three‐wire system, which is able to provide three different voltage levels, including positive ( V p ), negative ( V n ) outputs, and the sum of them ( V p + V n ) for DC units to easily interface with the DC microgrids and for DC‐AC application such as mid‐point clamped Multilevel converters. In such systems, if a fault happens in one of the poles, the other pole can operate to increase the reliability of the system [7]. Adjustable output DC voltage with a wide range of variety from negative to positive is one of the benefits of the bipolar converters, which makes their applications wider.…”