Search

Induction heating appliance operation is constrained by the nonlinear pot material behavior under the generated magnetic field. The equivalent load seen by the inverter varies with the intensity of the field, meaning that this variation is dependent on the mains voltage. In flexible-surface induction cooktops, this fact is combined with a high coil number and different pots to be powered simultaneously, increasing the complexity to control the transmitted power while maintaining proper mains current consumption. In this article, two noncomplementary asymmetrical modulations with in-cycle parameter variation are proposed for improved power factor correction while avoiding the need for switching frequency variation and intermodulation noise in multiload systems. The proposed strategies are analyzed and experimentally tested using a 3.6 kW multi-inverter prototype featuring five induction coils. [ABSTRACT FROM AUTHOR]

Electroporation is a phenomenon that increases the permeability of cells by applying an electric field. This technique has relevant applications to cancer treatment using both electrochemotherapy and tumor ablation using irreversible electroporation. In order to carry out these treatments, new power converters are needed to apply of output voltages of several kV and output currents of tens of A in pulses of a width of μs. In addition, to achieve safe and relapse-free treatments, it is necessary to generate a controlled and uniform electric field. A challenge in current treatments is to ensure effective treatments despite tissue heterogeneity. In this context, this article proposes a new pulse generator that allows the use of a multielectrode structure that enables the application of a uniform electric field in multiple directions to avoid issues related to tissue heterogeneity. The proposed generator also allows the continuous monitoring of the treatment to adequately control the generator and apply a safer and more effective treatment. An 18-output 1500-V experimental prototype was designed, implemented, and tested using vegetal tissue, proving the feasibility of this proposal. [ABSTRACT FROM AUTHOR]

Multi-output inverters have become a key enabling technology to increase surface flexibility in domestic induction heating appliances. The most commonly used power converter topologies are based on electromechanical relays in order to multiplex the connected loads and obtain a proper heat distribution. This solution, which is used in combination with other modulations such as square waveform, relies on the thermal inertia of the pot as it needs long power-averaging periods to reduce the reiteration of the switching noise. However, it presents a significant limitation in terms of acoustic noise, reliability, and thermal performance. To overcome these limitations, complete solid-state inverters that can be operated at higher frequencies are proposed. This change in the design paradigm of the pulse density modulation strategies leads to improved thermal control in the pot and better user experience, but at the same time increases challenges due to design constraints imposed by electromagnetic compatibility regulations. This article analyzes the possibilities of a new mains-synchronized pulse density modulation applied to a flexible induction cooktop that uses a multiple-output ZVS resonant inverter topology. The feasibility of the control strategies has been tested by means of a prototype featuring 12 2-kW induction heating loads. [ABSTRACT FROM AUTHOR]

Domestic induction heating appliances have improved the final user experience due to the advantages that this technology offers, such as flexibility, fast heating, cleanness, and safety. Currently, these appliances are implemented using several isolated electronic boards to be able to be powered from one or several mains phases, enabling their use in regions with different connections. In order to enhance this approach, a multiphase power factor correction rectifier is proposed in this article, improving significantly induction heating cookers. The topology is described, and a wide variety of modulation strategies are presented and analyzed, discussing their main advantages and disadvantages according to the conduction mode, operating frequency, switching mode, and control strategy. In order to validate this proposal, an 11 kW and up-to three-phase high power-density converter for domestic induction heating applications is implemented and experimentally analyzed, including its main waveforms and efficiency. Finally, a comparative evaluation is performed to enable the selection of the optimum modulation strategy for each specific application. [ABSTRACT FROM AUTHOR]

Industrial induction heating (IH) is a key manufacturing process due to its benefits in terms of efficiency, accurate output power control, and high performance. These features have made possible the extension of this technology to a wide range of industries from automotive to aeronautic, domestic, or renewable energies. One of the main challenges still present is the design of a high-performance and cost-effective process for those induction targets with complex geometries exposed to the magnetic field, being the most representative example gears present in most mechanical systems. Usually, in order to optimize the heating process, multifrequency IH systems are used, being often expensive and/or difficult to tune and control. The aim of this paper is, consequently, to propose a family of power converters able to supply the inductor system with two simultaneous frequencies in order to improve the heating process of the induction target. The proposed converter takes advantage of a multiresonant network allowing full control of the output power delivered at each frequency and, at the same time, a compact and cost-effective implementation. The proposed converter is analyzed, designed, and implemented, and experimental verification of its operation is provided in this paper. [ABSTRACT FROM AUTHOR]

Flexible cooking surfaces represent the most innovative and high-performance induction heating appliances nowadays. This paper presents a multiple-output resonant inverter for multicoil systems featuring high efficiency and flexible output power control for modern induction heating appliances. By adopting a matrix structure, the number of controlled devices can be significantly reduced while high control versatility is ensured. The proposed converter is first analyzed and, in order to prove the feasibility of the proposal, a multiple-output prototype is designed and implemented. The experimental results prove the correct converter operation and output power control with multiple induction heating loads, validating the proposed approach. [ABSTRACT FROM AUTHOR]

Induction heating (IH) has become the technology of choice in many industrial, domestic, and medical applications due to its high efficiency and performance. This paper proposes an interleaved resonant boost inverter featuring SiC three-phase module to achieve high efficiency and performance IH power supply. The proposed converter achieves high efficiency by reducing the current through the devices, while the use of an interleaved full-bridge configuration reduces input current ripple and provides additional control degrees. The proposed converter has been designed, implemented, and tested experimentally, proving the feasibility of this proposal. [ABSTRACT FROM PUBLISHER]

Induction heating (IH) is a key technology in modern household appliances and industries. Modern design trends require the design of high efficiency and multiple output power converters. This paper proposes a dual-output boost resonant full-bridge topology to provide a multiple-output converter with improved performance while keeping a cost-effective performance. The proposed converter is detailed and analyzed, and several modulation strategies are proposed to obtain proper output power control. Finally, an experimental prototype is built, verifying the proper operation and performance of the proposed topology. [ABSTRACT FROM PUBLISHER]

This paper presents a comparative evaluation of silicon carbide power devices for the domestic induction heating (IH) application, which currently has a major industrial, economic and social impact. The compared technologies include MOSFETs, normally on and normally off JFETs, as well as BJTs. These devices have been compared according to different figure-of-merit evaluating conduction and switching performance, efficiency, impact of temperature, as well as other driving and protection issues. To perform the proposed evaluation, a versatile test platform has been developed. As a result of this study, several differential features are identified and discussed, taking into account the pursued induction heating application. [ABSTRACT FROM PUBLISHER]

Domestic induction appliances require power converters that feature high efficiency and accurate power control in a wide range of operating conditions. To achieve this modulation techniques play a key role to optimize the power converter operation. In this paper, a series resonant inverter featuring reverse-blocking insulated gate bipolar transistors and an optimized modulation technique are proposed. An analytical study of the converter operation is performed, and the main simulation results are shown. The proposed topology reduces both conduction and switching losses, increasing significantly the power converter efficiency. Moreover, the proposed modulation technique achieves linear output power control, improving the final appliance performance. The results derived from this analysis are tested by means of an experimental prototype, verifying the feasibility of the proposed converter and modulation technique. [ABSTRACT FROM PUBLISHER]

This paper presents the analysis and design of a new ac-ac resonant converter applied to domestic induction heating. The proposed topology, based on the half-bridge series resonant inverter, uses only two diodes to rectify the mains voltage. The proposed converter can operate with zero-voltage switching during both switch-on and switch-off transitions. Moreover, this topology doubles the output voltage, and therefore, the current in the load is reduced for the same output power. As a consequence, the converter efficiency is significantly improved. The analytical and simulation results have been verified by means of a 3600-W induction heating prototype. An efficiency study has been carried out, obtaining values higher than 96%. [ABSTRACT FROM AUTHOR]