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Nowadays, the grid-connected solar photovoltaic (PV) system has been drawing significant attention due to the rapid development and the decreasing cost of solar panels. The efficiency and reliability of a grid-connected PV system mainly depend on the power conversion system and the control strategy. This article presents a new magnetic-linked 7-level active neutral point clamped (ANPC) converter, which requires less number of flying capacitors and also reduces the control complexity of the grid-connected PV system. The proposed converter topology utilizes the input dc bus voltage better than the traditional ANPC multilevel converter and also provides galvanic isolation to the grid-connected PV systems. The lack of galvanic isolation is one of the biggest problems faced by the power frequency transformerless grid-connected PV systems. The proposed magnetic-linked power converter is also validated through simulations in MATLAB/Simulink and through tests in a laboratory test platform. [ABSTRACT FROM AUTHOR]

A single-phase GaN-based bridgeless PFC Boost converter design is proposed regarding multi-domain optimisation concepts. A design guideline describing elements losses are presented concerning the selected power converter topology. Experimental results are also depicted in 750 W power prototype digitally controlled by an FPGA device using switching frequency up to 500 kHz per active switch.

The modular multilevel matrix converter (M^3C) is a power converter topology for ac to ac conversion that is suitable for high-power applications. The control of this converter is complex, particularly if ac system frequencies are similar. In these cases, the floating capacitors can present large voltage oscillations. Therefore, this study presents a new vector control system to enable the operation of the M^3C when the frequencies at the input and output are virtually the same. The effectiveness of the proposed method has been validated using simulations and experimental results from a prototype M^3C power converter with 27 cells.

A single-phase GaN-based bridgeless PFC Boost converter design is proposed regarding multi-domain optimisation concepts. A design guideline describing elements losses are presented concerning the selected power converter topology. Experimental results are also depicted in 750 W power prototype digitally controlled by an FPGA device using switching frequency up to 500 kHz per active switch. [ABSTRACT FROM AUTHOR]

The modular multilevel matrix converter (M3C) is a power converter topology for ac to ac conversion that is suitable for high-power applications. The control of this converter is complex, particularly if ac system frequencies are similar. In these cases, the floating capacitors can present large voltage oscillations. Therefore, this study presents a new vector control system to enable the operation of the M3C when the frequencies at the input and output are virtually the same. The effectiveness of the proposed method has been validated using simulations and experimental results from a prototype M3C power converter with 27 cells. [ABSTRACT FROM AUTHOR]

A power take-off (PTO) system for an oscillating water column (OWC) wave energy converter comprises a turbine-generator-power converter. In this study, only the topologies of the power converter that affect the load control algorithm are compared. A power converter for renewable energy is composed of a diode-dc/dc converter and a pulse-width modulation (PWM) converter operating at small and large capacities, respectively. However, selecting a power converter according to the capacity based on the characteristics of the wave energy converter, in which the input energy is highly fluctuating, can significantly reduce the power performance. Thus, to verify load control characteristics according to the topology of the power converter, the turbine-generator-power converter was incorporated in the modeling, and the power performance based on the power converter topology under various wave conditions was analyzed. Further, torque control to obtain the maximum power among load control algorithms was applied under irregular wave conditions, and the power performance and PTO system characteristics according to the torque coefficient were analyzed. The results of this study suggested an increase in the torque coefficient of the maximum power control for the operational stability of the OWC-WEC, and it was confirmed that the RPM characteristics of the PTO system were reduced.

Three-phase to three-phase power conversion with variable frequency and output voltage amplitude control can be realized with both matrix converter and indirect matrix converter configurations. Even if this two power converters have a different topology, the indirect configuration provides an equivalent circuit widely used to define matrix converter modulation strategies. The equivalence between the states of the two converters is well known but a discussion on indirect matrix converter relationships has never been deeply investigated. This paper discusses the equivalence between the two power converter configurations from a mathematical viewpoint, pointing out the intrinsic characteristics and potentialities of each of them. [ABSTRACT FROM AUTHOR]

A power take-off (PTO) system for an oscillating water column (OWC) wave energy converter comprises a turbine-generator-power converter. In this study, only the topologies of the power converter that affect the load control algorithm are compared. A power converter for renewable energy is composed of a diode-dc/dc converter and a pulse-width modulation (PWM) converter operating at small and large capacities, respectively. However, selecting a power converter according to the capacity based on the characteristics of the wave energy converter, in which the input energy is highly fluctuating, can significantly reduce the power performance. Thus, to verify load control characteristics according to the topology of the power converter, the turbine-generator-power converter was incorporated in the modeling, and the power performance based on the power converter topology under various wave conditions was analyzed. Further, torque control to obtain the maximum power among load control algorithms was applied under irregular wave conditions, and the power performance and PTO system characteristics according to the torque coefficient were analyzed. The results of this study suggested an increase in the torque coefficient of the maximum power control for the operational stability of the OWC-WEC, and it was confirmed that the RPM characteristics of the PTO system were reduced. [ABSTRACT FROM AUTHOR]