Multiport DC-DC Converters for Hybrid Energy Systems

Renewable energy sources (RESs) like solar and wind have gained attention for their potential to reduce reliance on fossil fuels and mitigate climate change. However, integrating multiple RESs into a power grid is challenging due to their unpredictable nature. Power electronic converters can manage hybrid energy systems by controlling power flow between RESs, storages, and the grid. Conventional single input dc-dc converters have limitations such as low efficiency, bulky designs, and complex control systems. Multiport dc-dc converters (MPCs) have emerged as a solution for hybridizing multiple sources, storages, and load systems by providing a common interface. Existing MPCs have limitations such as high component count, limited operational range, complex control strategies and restrictions on the number of inputs to list a few. Thus, there is a need to develop new MPCs that combine the advantages of existing designs while overcoming their limitations. Isolated MPCs with unipolar or bipolar outputs are needed that can accommodate any number of inputs, offer high voltage gain, use fixed magnetic components for galvanic isolation (regardless of the number of ports), and have a simplified control strategy. Additionally, new non-isolated MPCs with unipolar or bipolar outputs are required, featuring reduced component count, simultaneous power transfer and power flow between input ports, high voltage gain, low control complexity, and modular design allowing for arbitrary increase in the number of input ports. There is also an opportunity to apply MPCs in the integration of RESs and storages to ac grids through multilevel inverters for low component count, high efficiency, low harmonics, and higher power density. Further, advances in bipolar MPCs provide the chance to balance the dc bus without requiring a complex control system.acceptedVersio

Overview of Power Electronic Switches: A Summary of the Past, State-of-the-Art and Illumination of the Future

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Novel Isolated Multiport DC Converter with Natural Bipolar Symmetry for Renewable Energy Source Integration to DC Grids

Due to their greater reliability, efficiency, and resilience as compared to unipolar dc grid systems, bipolar dc grid systems are swiftly gaining popularity for the integration of renewable energy sources. However, development of multiport converters for bipolar microgrid systems is still progressing slowly in terms of reducing costs or improving power density and compact designs. This paper proposes a multiport isolated dc-dc converter with naturally symmetric bipolar outputs (MIBDC). With respect to the number of input ports, voltage gain, and output symmetry that the proposed converter naturally possesses, it outperforms its few competitors. Additionally, the proposed MIBDC significantly reduces component count and control complexity by employing a fixed transformer with only one primary and secondary winding for any number of inputs. The suggested converter’s performance in both open and closed loops is evaluated quantitatively in simulation and experimentally using OPAL-OP5700 RT’s hardware-in-the-loop (HIL) platform under various situations.publishedVersio

A comprehensive review of energy sources for unmanned aerial vehicles, their shortfalls and opportunities for improvements

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Hybrid Three-Phase Transformer-Based Multilevel Inverter With Reduced Component Count

The topology of the static synchronous compensator of reactive power for a low-voltage three-phase utility grid capable of asymmetric reactive power compensation in grid phases has been proposed and analysed. It is implemented using separate, independent cascaded H-bridge multilevel inverters for each phase. Every inverter includes two H-bridge cascades. The first cascade operating at grid frequency is implemented using thyristors, and the second one—operating at high frequency is based on the high-speed MOSFET transistors. The investigation shows that the proposed compensator is able to compensate the reactive power in a low-voltage three-phase grid when phases are loaded by highly asymmetrical reactive loads and provides up to three times lower power losses in the compensator as compared with the situation when the compensator is based on the conventional three-level inverters implemented using IGBT transistors.publishedVersio

Hybrid Three-Phase Transformer-Based Multilevel Inverter With Reduced Component Count

The topology of the static synchronous compensator of reactive power for a low-voltage three-phase utility grid capable of asymmetric reactive power compensation in grid phases has been proposed and analysed. It is implemented using separate, independent cascaded H-bridge multilevel inverters for each phase. Every inverter includes two H-bridge cascades. The first cascade operating at grid frequency is implemented using thyristors, and the second one—operating at high frequency is based on the high-speed MOSFET transistors. The investigation shows that the proposed compensator is able to compensate the reactive power in a low-voltage three-phase grid when phases are loaded by highly asymmetrical reactive loads and provides up to three times lower power losses in the compensator as compared with the situation when the compensator is based on the conventional three-level inverters implemented using IGBT transistors