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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]

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]

Resonant power conversion provides high-efficiency and high-power-density power converters that have boosted the performance of many applications, including induction heating (IH). One of the main challenges of such converters is the fine tuning and operation monitoring of the resonant tank, especially when it is highly variable. This paper proposes an field-programmable gate array (FPGA)-based load identification technique based on measuring the resonant capacitor voltage and calculating its spectral components. This approach proposes an accurate and cost-effective implementation, since the sensing, conditioning, and analog-to-digital conversion systems can be significantly simplified to a single low-harmonic-content signal. The proposed approach has been tested using a wide range of IH loads and operating conditions, proving the feasibility of this proposal. [ABSTRACT FROM AUTHOR]

Induction heating is nowadays a key technology due to its advantages in terms of performance and efficiency, which has boosted its adoption in industrial, domestic, and medical applications, among others. Recent developments in domestic induction heating are focused on flexible cooking surfaces with higher output power. The design requirements of this cooktops are more restrictive due to electromagnetic compatibility (EMC), power density, efficiency, control complexity, and cost. In order to overcome these issues, the use of active power factor corrector (PFC) rectifiers is proposed. This paper proposes and analyzes a complete set of modulation strategies for a single-phase boost-type PFC applied to domestic induction heating. A comparative analysis is performed taking into account the device stress, efficiency, operating frequency, control complexity, and EMC performance. This discussion reveals the advantages and disadvantages of each modulation strategy according to the final implementation requirements and the application area. [ABSTRACT FROM AUTHOR]

Induction heating has become the most advance heating process due to benefits, such as efficiency, performance, cleanness, and safety. In this process, the electromagnetic coupling between the induction coil and the induction target is a key, determining the heating performance as well as the resonant power converter operation. This letter proposes an accurate and cost-effective resonant tank identification method applied to induction heating systems. It is based on monitoring the resonant capacitor voltage in order to calculate the resonant tank quality factor. The proposed methodology has been tested using a versatile power electronics test bench applied to domestic induction heating, proving the feasibility of this proposal. [ABSTRACT FROM PUBLISHER]

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]

New semiconductor technology is enabling the design of more reliable and high performance power converters. In particular, silicon carbide (SiC) technology provides faster switching times, higher operating temperature, and higher blocking voltage. Among the new SiC devices, bipolar junction transistors (BJTs) present interesting features in terms of conduction and switching losses. However, one of the main drawbacks is that these devices have low gain, requiring high base current to activate them. As a consequence, the base drive circuit becomes more complex and the final efficiency is decreased. This letter presents an optimized base drive circuit for a zero-voltage switching series resonant inverter. The proposed circuit maximizes the driver efficiency and minimizes the driver current requirements. Moreover, the proposed circuit optimizes the power converter switching conditions, increasing the converter efficiency. The proposed base drive circuit has been tested with a SiC-BJT-based series resonant inverter applied to induction heating. [ABSTRACT FROM AUTHOR]

Induction heating systems are the technology of choice in many industrial, domestic, and medical applications due to its high performance. The core component of such systems is the power supply, which is usually composed of a rectifier stage and a resonant inverter. In order to simplify and further optimize the performance of the power supply, a class-E direct ac–ac converter featuring multicycle modulations is proposed in this paper. The proposed converter is composed of two switching devices that enable the direct ac–ac conversion. Single- and multicycle operation modes have been analytically described to prove the benefits, in terms of peak voltage reduction and output power control capabilities. A prototype featuring SiC junction-gate field-effect transistor devices, which perfectly fit these applications, has been designed and built to prove the feasibility of the proposed converter. The experimental results match the analytical results and validate the benefits of this converter. [ABSTRACT FROM PUBLISHER]

Efficiency is a key design parameter when designing the power converters for domestic induction heating applications, since it determines not only the environmental impact of the power converter but also its final performance and reliability. In this paper, the design of high-efficiency converters for induction heating applications is discussed, focusing on the advantages of using wide bandgap devices. As a conclusion, a multiple-output boost resonant ac-ac converter is proposed, significantly improving current state-of-the-art efficiency and achieving a reduced component-count solution for multiple-load systems. The proposed converter has been tested through a dual-output boost resonant inverter for domestic induction heating applications. The design procedure is detailed, including the design of an optimized gate drive circuit for this application. Experimental results show significant improvements in efficiency in the whole operating range, and an accurate output power control, proving the benefits and feasibility of the proposed SiC-based converter. [ABSTRACT FROM AUTHOR]

Domestic induction heating (IH) is currently the technology of choice in modern domestic applications due to its advantages regarding fast heating time, efficiency, and improved control. New design trends pursue the implementation of new cost-effective topologies with higher efficiency levels. In order to achieve this aim, a direct ac–ac boost resonant converter is proposed in this paper. The main features of this proposal are the improved efficiency, reduced component count, and proper output power control. A detailed analytical model leading to closed-form expressions of the main magnitudes is presented, and a converter design procedure is proposed. In addition, an experimental prototype has been designed and built to prove the expected converter performance and the accurateness of the analytical model. The experimental results are in good agreement with the analytical ones and prove the feasibility of the proposed converter for the IH application. [ABSTRACT FROM AUTHOR]