This study presents an innovative approach where both sides of a back‐to‐back (BtB) system are controlled using the synchronverter approach, allowing to control the power transfer through the converters as it would be in a real motor–generator pair system. A novel way to transfer the DC voltage control loop in the BtB converter is proposed, letting to a softer and less noisy power transferring, as shown in simulation results. The modelling equations of the synchronverter and the traditional dq frame in a BtB converter are presented in this work. In addition, a comparison between these two control approaches using three different performance indexes is done, showing that the power transfer behaviour using the synchronverter approach is significantly improved. Finally, the ability of the BtB converter working as a power balancer system (PBS) to manage congestion between two distribution networks in a test bed case is tested. Results show that it is possible to obtain the PBS power quality benefits without the additional phase‐locked loop units and the decoupling process, necessary with the dq frame, resulting in a simpler controller design.

Microgrids are considered an adequate alternative to overcome the challenges involving integrating distributed energy resources in distribution systems to contribute to the ’Three D’ trend in the electricity sector, i.e., decentralize, decarbonize, and digitize electricity. This paper reviews the most relevant works to establish a baseline for the advancement and development of smart transformer-based meshed hybrid microgrids and energy management systems. First, the structure of the solid-state transformers as smart transformers and their potential application as an energy router in a microgrid is discussed. Then, the principle of conformation of meshed hybrid microgrids based on a smart transformer and the topologies reported in the literature are reviewed. Finally, power management systems integrated into smart transformers-based meshed hybrid microgrids are studied. According to the findings and conclusions, it is considered that smart transformers-based meshed hybrid microgrids operated by an optimal energy management system under uncertainty are a potentially feasible technological alternative for the adequate penetration of distributed energy resources into local distribution systems.

This article proposes a shunt active filter (SAF) operating as a Synchronverter to enhance its performance, including the virtual inertia functionality. The SAF behaves as a voltage source with a low-impedance path for harmonic contents. Synchronverter behavior is used together with selective filtering through proportional-resonant controllers to provide selective harmonic filtering of the load current, selective harmonic blocking of the source current, and low-impedance path for nonselected harmonic contents from the load and the source currents. The virtual inertia functionality aims to contribute to frequency stability during power system transients. Besides filtering unbalanced and harmonic contents and compensating for reactive power, the SAF contributes to inertia response during frequency transients. A tuning design method is proposed to ensure stability and proper conditioning of the power-quality issues. The reduced quantity of parameters to be tuned is another advantage of the proposed controller. Simulation and experimental results validate the compensation performance of the SAF.

The smart transformer (ST) is a multiport and multi-stage converter that allows for the formation of meshed hybrid microgrids (MHMs) by enabling AC-DC ports in medium and low voltage. This type of microgrid has advantages over the performance of conventional hybrid AC-DC microgrids (HMGs); however, the number of degrees of freedom of the ST increases the complexity of the energy management systems (EMSs), which require adequate and accurate modeling of the power flow of the converters and the MG to find the feasible solution of optimal power flow (OPF) problems in the MHM. An ST’s equivalent power flow model is proposed for formulating the MHM OPF problem and developing low-frequency equivalent models integrated with a decoupled hierarchical control architecture under a real-time simulation approach to the ST-based MHM. A simulation model of the MHM in the Simulink^® environment of Matlab^{® 9.12} is developed and implemented under a digital real-time simulation (DRTS) approach on the OPAL-RT^® platform. This model allows for determining the accuracy of the developed equivalent models, both low-frequency and power flow, and determining the MHM performance based on optimal day-ahead scheduling. Simulation test results demonstrated the ST equivalent model’s accuracy and the MHM’s accuracy for OPF problems with an optimal day-ahead scheduling horizon based on the model-in-the-loop (MIL) and DRTS approach.

This work introduces a boost converter with quadratic gain. Its main advantage compared to well-known similar quadratic boost converters is that it requires capacitors with a relatively small capacitance and inductors with small inductance, leading to a reduction in the size or stored energy while performing a power conversion of similar power rating and the same switching ripples in both the input current and the output voltage. It is inspired by the recently introduced ISB converter and uses a specific PWM method. This results in achieving switching ripple constraints while using smaller energy storage elements (capacitors and inductors). The updated converter offers the same voltage gain compared to the conventional quadratic boost topology with the benefit of compact component sizes. While it has more passive elements, they are of reduced size. An analysis of energy storage revealed that this new converter uses only half the energy in inductors and 14% in capacitors when compared to specific design parameters.