Search

The main contribution of this paper is to present a simple algorithm that theoretically and numerically assesses the switching angles of an inverter operated with the SPWM technique. This technique is the most widely used for eliminating harmonics in DC-AC converters for powering motors, renewable energy applications, household appliances, etc. Unlike conventional implementations of the SPWM technique based on the analog or digital comparison of a sinusoidal signal with a triangular signal, this paper mathematically performs this comparison. It proposes a simple solution to solve the transcendental equations arising from the mathematical analysis numerically. The technique is validated by calculating the total harmonic distortion (THD) of the generated signal theoretically and numerically, and the results indicate that the calculated angles produce the same distribution of harmonics calculated analytically and numerically. The algorithm is limited to single-phase inverters with unipolar SPWM. [ABSTRACT FROM AUTHOR]

This paper aims to propose a new sizing approach to reduce the footprint and optimize the performance of an LCL filter implemented in photovoltaic systems using grid-connected single-phase microinverters. In particular, the analysis is carried out on a single-phase full-bridge inverter, assuming the following two conditions: (1) a unit power factor at the connection point between the AC grid and the LCL filter; (2) a control circuit based on unipolar sinusoidal pulse width modulation (SPWM). In particular, the ripple and harmonics of the LCL filter input current and the current injected into the grid are analyzed. The results of the Simulink simulation and the experimental tests carried out confirm that it is possible to considerably reduce filter volume by optimizing each passive component compared with what is already available in the literature while guaranteeing excellent filtering performance. Specifically, the inductance values were reduced by almost 40% and the capacitor value by almost 100%. The main applications of this new design methodology are for use in single-phase microinverters connected to the grid and for research purposes in power electronics and optimization. [ABSTRACT FROM AUTHOR]

The main contribution of this paper is the inductive compensation of a wireless inductive power transmission circuit (IPT) with resonant open-loop inductive coupling. The variations in the coupling coefficient k due to the misalignment of the transmitter and receiver are compensated with only one auxiliary inductance in the primary of the inductive coupling. A low-power prototype was implemented with the following specifications: input voltage Vin = 27.5 V, output power Po = 10 W, switching frequency f = 500 kHz, output voltage Vo = 12 V, transmission distance d = 1.5 mm. Experimental results varying the distance "d" with several values of the compensation inductor demonstrate the feasibility of the proposal. An efficiency of 75.10% under nominal conditions was achieved. This proposal is a simple compensation topology for wireless chargers of cellular phones presenting small distances between the transmitter and receiver. [ABSTRACT FROM AUTHOR]

This study compares ripple port, stacked switched capacitor, and capacitive energy storage architectures for active power decoupling, comparing the number of components, performance, energy density, DC-link capacitor reduction, efficiency, and frequency operation to highlight their main benefits and drawbacks for single-phase grid-connected applications. The overview reveals equivalent effective energy density without electrolytic capacitors, as well as enhanced simplicity, performance, and durability, thereby providing stacked switched capacitors as an attractive power-decoupling alternative for multi-stage connected applications, based on the principle that its individual buffer capacitors absorb and deliver energy without tightly constraining their individual terminal voltages, while maintaining a narrow range voltage at the buffer DC port. [ABSTRACT FROM AUTHOR]

Summary: In this paper, the analysis, design, and implementation of a power supply based on a multi‐stage‐shunt class E amplifier applied to ozone generation are presented. The proposed topology operates with pulsating waveforms and allows unidirectional energy flow from the power supply to the load with no energy return. Furthermore, due to the multi‐stage operation, it presents a lower stress in the switches compared with other similar topologies. To validate the proposed topology, a prototype was designed to feed a set of ozone generating cells in a power range of 0 to 500 W. This prototype provides an efficiency of 95% with an ozone production of 10.5 g/h and efficacy of 22.89 g/kWh. The proposed power supply is an alternative to feed any other type of dielectric barrier discharge load while keeping the efficiency of the power supply above 90%. The analysis, design, and implementation of a power supply based on a multi‐stage‐shunt class E amplifier applied to ozone generation are presented; due to the multi‐stage operation, it presents a lower stress in the switches compared with other similar topologies and higher efficiency. To validate the proposed topology, a prototype was designed to feed a set of ozone generating cells in a power range of 0 to 500 W. [ABSTRACT FROM AUTHOR]

The main contribution of this paper is the use of sensorless active diodes to generate the gate signals for a three-phase boost-rectifier with a self-powered control scheme. The sensorless operation is achieved making use of the gate control signals generated by the active diode schemes on each of the switching devices using a pulse width half-controlled boost rectifier modulation technique (PWM-HCBR). The proposed scheme synchronizes the gate control signals with a three phase voltage supply. Autonomous operation is obtained making use of the output DC bus to feed the control circuitry, the active diodes and the driver circuitry. The three-phase boost-rectifier is supplied by a three-phase permanent magnet electric generator powered by a solar concentrator dish with variable voltage and variable frequency conditions. Experimental results report an efficiency of up to 94.6% for 25 W and an input of 3.6 V peak per phase with 450. [ABSTRACT FROM AUTHOR]

The arrangement of the full-bridge, current-source inverter as a power supply for ozone generators providing high power factor (PF) and high electrical efficiency in a single stage is the main contribution of this paper. The corresponding design, simulation, and experimental results are presented. Also, the use of the current-fed, full-bridge resonant inverter for PF correction in ozone generation applications is discussed. The proposed power supply consists of an ac supply, a single rectifier bridge, an input inductor to the inverter, four switches, an LC parallel resonant tank, a resonant transformer, and a set of ozone generating cells. Experimental results with the proposed topology provided 96% for PF, 91% for electrical efficiency, and ozone production of 614 mgO3/min, satisfying the requirements of the standard 61000-3-2, class A. [ABSTRACT FROM AUTHOR]