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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. [ABSTRACT FROM AUTHOR]

The sinusoidal modulation per phase and vector modulation are the most commonly employed pulse-width modulation techniques in three-phase inverters. There exist different schemes based on the variable switching frequency technique such as the hysteresis and finite control set based on the model predictive control with constant sampling period. This study proposes an alternative scheme by implementing a finite-control-set for a three-phase voltage-fed inverter. Here, a model solution-based control scheme is utilised, which allows the usage of a single controller resulting from the system simplification. It is shown that the proposed scheme exhibits an improved dynamic response under load variations and allows an easy digital implementation, which is the indication of its potential application from a practical point of view. A complete analysis and discussion of the proposed scheme as well as implementation and experimental results are provided to illustrate its effectiveness. [ABSTRACT FROM AUTHOR]

DC/AC converters are widely used in several applications; traditionally, they can be classified in two types: the voltage-source inverters (VSIs) and the current-source inverters (CSIs). Their use depends on their application; however, some of them are common for both types of converters. Another possibility for the dc/ac conversion is the multilevel configuration, and the most analyzed is the VSI. In this paper, a different multilevel CSI is proposed: the paralleled configuration. To control the converter, a different sinusoidal pulse with modulation is employed; it consists of modifying the reference signal instead of using multiple carriers. Additionally, a balancing method for the inductor currents is given. The operation, analysis, and implementation are presented; moreover, simulation and experimental results are shown. [ABSTRACT FROM AUTHOR]

In this paper, a single-stage high-power-factor high-efficiency electronic ballast for compact fluorescent lamps is presented. The proposed topology uses two voltage sources connected in series to feed the inverter ballasting the lamp, one of them consists in the rectified line voltage and the other in a dc-dc converter operating in discontinuous conduction mode. In this way, the converter processes a lower energy than the nominal power of the lamp. The proposed topology presents simplicity, high-power-factor, low current crest factor, and high efficiency. [ABSTRACT FROM AUTHOR]

Nowadays, the use of the hardware in the loop (HIL) simulation has gained popularity among researchers all over the world. One of its main applications is the simulation of power electronics converters. However, the equipment designed for this purpose is difficult to acquire for some universities or research centers, so ad-hoc solutions for the implementation of HIL simulation in low-cost hardware for power electronics converters is a novel research topic. However, the information regarding implementation is written at a high technical level and in a specific language that is not easy for non-expert users to understand. In this paper, a systematic methodology using LabVIEW software (LabVIEW 2018) for HIL simulation is shown. A fast and easy implementation of power converter topologies is obtained by means of the differential equations that define each state of the power converter. Five simple steps are considered: designing the converter, modeling the converter, solving the model using a numerical method, programming an off-line simulation of the model using fixed-point representation, and implementing the solution of the model in a Field-Programmable Gate Array (FPGA). This methodology is intended for people with no experience in the use of languages as Very High-Speed Integrated Circuit Hardware Description Language (VHDL) for Real-Time Simulation (RTS) and HIL simulation. In order to prove the methodology's effectiveness and easiness, two converters were simulated—a buck converter and a three-phase Voltage Source Inverter (VSI)—and compared with the simulation of commercial software (PSIM® v9.0) and a real power converter. [ABSTRACT FROM AUTHOR]