There are multiples conditions that lead to partial shading conditions (PSC) in photovoltaic systems (PV). Under these conditions, the harvested energy decreases in the PV system. The maximum power point tracking (MPPT) controller aims to harvest the greatest amount of energy even under partial shading conditions. The simplest available MPPT algorithms fail on PSC, whereas the complex ones are effective but require high computational resources and experience in this type of systems. This paper presents a new MPPT algorithm that is simple but effective in tracking the global maximum power point even in PSC. The simulation and experimental results show excellent performance of the proposed algorithm. Additionally, a comparison with a previously proposed algorithm is presented. The comparison shows that the proposal in this paper is faster in tracking the maximum power point than complex algorithms.

This paper presents the mathematical modeling and control design procedure of the compressor motor of an air conditioner using the energy from a photovoltaic system combined with the power grid in a DC microgrid. A comprehensive model considers the interconnection of the photovoltaic cells with their associated DC/DC converter, the DC bus, the three-phase squirrel-cage induction motor with its driver, the bidirectional DC/AC converter, the output filter, and the power grid. The state-of-the-art showed that a complete mathematical model of the proposed system is unavailable. Therefore, the mathematical model of the system is compared and validated in simulation with a block diagram in the Matlab/Simulink environment. In addition, several control approaches are used in the whole system to track the maximum power point of the photovoltaic cells, obtain a soft start on the machine, control the velocity using the variable frequency drive, regulate the DC bus voltage, and manage the power flow between the DC bus and the power grid.

According to the International Electrotechnical Commission, medium voltage ranges from 1 kV to 36 kV. In this voltage range, the field of power electronics has been focusing on developing power converters with high efficiency. Converters for such applications include solid-state transformers, energy storage systems for vehicle charging, electric aircraft, etc. Power ranges could reach tens to hundreds of kilowatts at relatively high frequency (10–50 kHz). Currently, there are no high-frequency power semiconductors capable of switching these voltage levels. Instead of using a single power switch, a string of power switches is used. The upper switches in the string require special attention because they need the highest isolation capabilities and a floating control signal and power supply for the gate driver. Many techniques have been proposed to accomplish this, but they commonly use separate circuits for the control signal and the power supply, increasing the cost, size, and complexity of the gate driver. This paper presents a gate driver for medium voltage with high-voltage isolation capabilities in a single structure for the control signal and the power supply. The proposed gate driver uses a resonant converter that transmits power within the gate driver information. A demodulator separates the gate driver information from the power signal, obtaining the power supply and the control signal for the switch. The paper includes simulation and experimental results that demonstrate the viability of the proposal. The experimental results show the principal features of the gate driver, achieving improvements in complexity, isolation capabilities, and both rise and fall times for large input capacitances of power semiconductor switches. The proposed gate driver presents a rise time of 44 ns and a fall time of 46 ns for the gate input capacitance of currently available SiC MOSFETs. The isolation barrier uses a 25 mm air gap, achieving an isolation capability of approximately 68.2 kV, which exceeds the requirements for MV applications.

In energy-harvesting storage systems, in order to guarantee the correct operation and integration of its parts into the system, different power converters must be used. Using several stages increases energy processing and therefore decreases the overall efficiency of the system. In this paper, an integrated multi-port converter with galvanic isolation is proposed. It allows the transfer of energy between the solar panel, the battery, and the user using the fewest possible stages, thus maximizing efficiency. Operating in three modes depending on the battery’s state of charge, solar radiation and load conditions, the converter can conduct electric power between its ports. The proposal was validated in a 1 kW prototype performing the different modes of operation. It should be noted that a PV emulator (ETS150X5.6C-PVF) was used in the experimental setup; by means of this device, conditions such as solar irradiance and temperature, which affect the energy generation of PV panels, were controlled. In addition, the transformer employed in the prototype implementation was handmade; therefore, its design could be improved to obtain better performance. The experimental results show efficiencies exceeding 94%, and an analysis of the distribution of losses in the circuit was carried out. Also, a comparison with previous proposals is presented, showing competitive features.

This paper presents an overview of fault-tolerance strategies in multilevel converters, with emphasis on fault diagnosis as a fundamental stage. Classical multilevel converter topologies and their main application areas, such as motor drives, renewable energy systems, and smart grids, are first introduced, along with the most common faults affecting power semiconductor devices. Fault diagnosis techniques reported in the literature are then reviewed and classified into model-based, signal-based, hardware-based, and hybrid approaches. The operating principles, measured variables, and implementation requirements of each category are analyzed, with particular attention to the fault detection times. A comparative analysis is provided, highlighting the fastest diagnostic strategies and their application to different multilevel converter topologies. This review consolidates recent advances and identifies current trends and challenges, providing a useful reference for the development of faster and more reliable fault-tolerant solutions in multilevel power converters.