This work analyzes interlinking converter control in hybrid AC/DC microgrids. The paper addresses the state-of-the-art general hybrid microgrid structure. The key power electronics topologies are used as bidirectional interface converters in the AC and DC parts. Different control structures of hybrid microgrids are categorized, followed by the classification of the main control functions, their control strategies, and the control techniques and a summary of their positive and negative aspects and applications. Control functions, strategies and techniques are classified in the interlinking-converter based. Finally, overall control objectives, time-scaled control structures, and their strategies are outlined. The prospects, main challenges, research gaps, and the trend of the hybrid microgrid structure and control are reviewed and summarized in the conclusions.

This article studies the model predictive control (MPC) for a twisted buck–boost inverter based on unfolding circuit. The focus is on the practical implementation of the MPC algorithm for the microcontroller designed for application in power electronics. Selection of proper cost function parameters along with a continuous control set reduced prediction horizon, at the same time keeping good quality of the grid current. The results showed that simplified differential equations and a multicore microcontroller contribute to the sample time reduction, which in turn increases the sampling frequency with the corresponding increase in the output current quality. The simulation and experimental results confirmed theoretical predictions. In conclusion, the MPC technique suits for reducing zero-crossing distortion and in applications based on unfolding circuit.

This article focuses on fast chargers of electric vehicles. One of the crucial parts of a fast charger is the secondary charging converter that must be able to regulate efficiently battery charge voltage and current. To be able to use the electric vehicle battery as a temporary energy storage in the electric grid, the topology of a charging converter must enable a bidirectional energy flow. Bidirectional converters need an additional boost circuit to stabilize the battery voltage while draining energy from it. Class 3 unidirectional charging converters could be realized with a current doubler rectifier topology and bidirectional ones with a controllable full-bridge rectifier/inverter, resulting from its advantage over the current doubler in this operational mode. A quasi Z source could be used as a filter/boost circuit.

Over two third of total electricity produced are consumed by residential and commercial buildings. According to this the nearly zero-energy building (NZEB) with local renewable power sources will play important role to reduce greenhouse gases. Local and intermittent renewable power generation is challenge for power quality and supply reliability of NZEB. It means higher demand for an Energy Management System (EMS) to provide power quality and balance between load and generation. This paper gives a brief overview of EMS for residential buildings. To test an EMS, the behavior of NZEB must be simulated in the laboratory. For this purpose, an experimental system was developed which includes variable load and its control as a part of EMS. Two load simulation methods for load management were studied and experimentally verified.

DC microgrids require rapid and reliable techniques for residual current detection and protection against short circuit, overcurrent, and overvoltage. Solid-state circuit breakers provide viable high-speed protection for DC microgrids. Microcontroller-based control circuits, in conjunction with a diverse array of sensors, facilitate rapid fault identification, measurement of various grid parameters, telemetry, and load control, while metal-oxide-semiconductor field-effect transistor based switching cells enable swift isolation of these faults. A device that integrates bidirectional solid-state circuit breaker (SSCB) and residual current device (RCD) features into a single hybrid unit is required to safeguard users and linked apparatus. Only a limited number of proven solutions for measuring residual current can be directly utilized in DC grids. Hall effect sensors offer low power consumption and compact physical dimensions. Nonetheless, fluxgate-based current sensors provide enhanced linearity and precision. Therefore, a hybrid SSCB/RCD protection device that operates as such is proposed in this paper. The primary design and implementation challenges of DC microgrids and various residual current measurement techniques were examined to assess the proposed hybrid device. The power circuit topology was selected, and a compact prototype was developed and evaluated in the laboratory. Conducted tests demonstrated its conformance with requirements, usefulness in residential 350 V DC microgrids, and capability to safeguard the microgrid from short circuits, users from electric shock, and the grid from overloads caused by connected devices.