Hybrid microgrids are systems that enable the interconnection of AC and DC networks within a unified framework, optimizing the integration of energy storage systems and DC-based renewable energy sources with the protection schemes and AC loads, predominantly induction motors. In this context, the integration of an Interlink Power Converter that facilitates AC-DC interconnection is strategically advantageous from an operational standpoint. Furthermore, adopting a multicell-based Interlink Power Converter offers additional benefits, such as the generation of multilevel voltage waveforms, which enhances the integration of filters in AC systems. Additionally, multicell-based topologies ensure scalability and fault-tolerant operation. This paper introduces an Interlink Power Converter topology based on multicell systems, which enhances system scalability. The cells comprising the system are configured in a series-parallel arrangement, enabling effective and straightforward internal balancing, while also allowing the seamless integration of energy storage systems within the converter itself. This feature enhances the system's flexibility and controllability, providing a robust solution for hybrid microgrid applications.

Battery Energy Storage Systems (BESS) offer scalable energy storage solutions, especially valuable for remote, off-grid applications. However, traditional battery packs with fixed series-parallel configurations lack reconfigurability and are limited by the weakest cell, hindering their application for second-life batteries. The Modular Multilevel Series-Parallel Converter (MMSPC) addresses these limitations by enabling dynamic reconfiguration, optimizing cell balancing, and enhancing energy control. This paper experimentally evaluates a single-phase BESS based on the MMSPC with an output power equivalent to 2 kW and two battery units (155V), demonstrating stable output and reduced internal losses across varied battery parameters.

Modular multilevel series-parallel converters (MM-SPC) have become a suitable solution to provide higher operating voltages, fault tolerance operation, and reliability at a reduced cost, due to their ability to achieve a simpler internal voltage balance. Therefore, MMSPC is a promising solution for applications where the nominal operating conditions are high voltage levels on the DC side and high current ratings on the AC side of the system. To allow this operation, it is necessary to design the system with parallelization in each phase. Therefore, this article proposes a design that incorporates parallelization in each phases and analyzes the internal cross-circulating current generated due to parallelization. This current creates an unbalance and internal losses in the converter. In order to compensate for the cross-circulating current, two cases are compared: the first one with decoupled inductors in their phases, and the second one with coupled inductors. This way, a comparison is made to determine which case provides greater compensation of the circulating current, allowing for the delivery of a high current at the converter's output with the least possible imbalance and internal losses.