Induction Heating Power Supply Research Articles

Power Supply for Variable Frequency Induction Heating Using MERS Soft-Switching High Frequency Inverter

Variable frequency induction heating has great potential for industrial heating applications due to the possibility of achieving heating distribution control; however, large-scale induction heating with variable frequency has not yet been introduced for practical use. This paper proposes a high frequency soft-switching inverter for induction heating that can achieve variable frequency operation. One challenge of variable frequency induction heating is increasing power electronics ratings. This paper indicates that its current source type dc-link configuration and soft-switching characteristics can make it possible to build a large-scale system with variable frequency capability. A 90-kVA 150-1000Hz variable frequency experimental power supply for steel strip induction heating was developed. Experiments confirmed the feasibility of variable frequency induction heating with proposed converter and the advantages of variable frequency operation.

XRF inductive bead fusion and PLC based control system

In order to ensure high-quality X-ray fluorescence spectrometry (XRF) analysis, an inductive bead fusion machine was developed. The prototype consists of super-audio IGBT induction heating power supply, rotation and swing mechanisms, and programmable logic controller (PLC). The system can realize sequence control, mechanical movement control, output current and temperature control. Experimental results show that the power supply can operate at an ideal quasi-resonant state, in which the expected power output and the required temperature can be achieved for rapid heating and the uniform formation of glass beads respectively.

Zero-voltage switching converter absorbing parasitic parameters for super high frequency induction heating

This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this converter is competent for super high frequency applications.

Experimental analysis of the performance of cold crucible induction glass melter

An engineering scale cold crucible induction glass melter was developed employing a transistor-based induction heating power supply with an operating frequency of 200 kHz. Experimental investigations were carried out to study its electrical and thermal performances during various stages of operations such as start-up heating, batch melting and idling. Sodium borosilicate glass with an electrical conductivity of 1.9 Ω cm and viscosity of 9.4 Poise at 1000 °C was used for the present study. Calorimetric measurements were carried out to determine the electrical and thermal efficiencies of various subsystems involved. An electrical efficiency of 80.4%, a melter efficiency of 20.83% and an over all efficiency of 16.74% were experimentally obtained for batch melting of sodium borosilicate glass in an engineering scale cold crucible induction glass melting system.

Multilevel inverter-based dual-frequency power supply

Most existing power supplies for induction heating equipment produce voltage at a single (adjustable) frequency. Recently, however, induction heating power supplies that produce voltage at two (adjustable) frequencies simultaneously have been introduced and commercialized. These represent a significant development particularly for heat-treating workpieces with uneven geometries, such as gears. Still, the existing approaches to dual-frequency voltage generation could be improved upon to achieve better control, higher efficiency, and reduced electromagnetic interference. This letter proposes the use of multilevel inverters for providing power at two frequencies simultaneously. It describes how the stepping angles for the desired output from such inverters can be determined. Furthermore, experimental results are presented as verification of the concept and to demonstrate the achievement of improved harmonic level control and reduced device switching frequency.

Surge analysis of induction heating power supply with PLL

Surges are undesirable with respect to both the reliability and the efficiency of power devices. In this paper, the surge mechanism of an induction heating power supply is studied. First, a modified phase locked loop (PLL) controller is proposed such that the changing resonant frequency of the heated load can be tracked correctly and the zero voltage switching (ZVS) can be reliably maintained simultaneously. Then, a very simple and practical surge model is proposed. Surge analyses for both ZVS and non-ZVS modes are made in sequence. It is found that the extra energy built up in the line inductance during the reverse recovery process of the diodes plays a very important role in generating huge voltages. Finally, some simulation and measured results are provided to verify the validity of the proposed surge model.

高周波誘導加熱を利用したディーゼルエンジン排気ガス浄化システム

Recently, the regulation to the air pollution is required from a viewpoint of environmental issue. The exhaust gas from the diesel engine is one of the factor that the air pollution is caused. Authors have taken note of PM (Particulate Matter) in exhaust gas and have proposed the combustion system of PM by means of high frequency induction heating. In this paper, as experimental results, it is proved that PM is reduced by PM reduction system utilizing high frequency induction heating. Furthermore, a novel high frequency inverter as the power supply for high frequency induction heating is proposed. And the circuit characteristics are clarified. As a result, although the circuit parameters are changed according to temperature in order to heat a metallic filter to high temperature, this inverter has realized stable operation.

Measurement of near-fields radiated by an induction heating power supply

Induction coil and the extension cable of an induction heating power supply radiate electromagnetic noise and often give disturbance to other equipment and systems closely located. In this paper a method for measuring near‐fields radiated by this system is proposed. Related data measured by using near‐field probes and spectrum analyzer are processed and a software is developed for calculating antenna factor. The electric field results are given in graphics.

Zero Current-Soft Switched High-Frequency Resonant Inverter with Fixed Frequency Voltage Regulation Function and Its Performance Analysis.

This paper is mainly concerned with a switching device voltage-clamped type half-bridge topology of new instantaneous resonant current vector-regulated high-frequency inverter with phase-shifting control which efficiently operates at zero-current soft switching mode in order to minimize switching losses and electrical stresses of the switching device over a wide voltage regulation range.This resonant inverter using two resonant switches and a resonant tank is more suitable for high-power induction-heating power supplies high-intensity ultrasonic generators and switched-mode DC-DC converters.This ZCS high-frequency inverter for induction-heating load are analyzed introducing normalized resonant and load circuit parameters and control variable on the basis of the computer-aided simulation. The load and frequency regulation characteristics of the proposed inverter are illustrated with a normalized expression in addition to voltage and current peak values of the power semiconductor device. Its simulation results are illustrated as compared with the experimental results obtained from trially-produced breadboard.

Single ended resonant power supply for induction heating

Details are given of a zero current switched Class E prototype power supply suitable for small scale induction heating applications. The unit operates with a minimum frequency of 40 kHz providing a peak output power of 3kW using a single GTO device.

New VVVF control-based high-frequency resonant inverters using static induction transistors

Abstract Voltage-fed high-frequency resonant inverters are proposed having a variable-voltage variable-frequency (VVVF) control function based on new circuit topologies called resonant voltage phasor controlled type and current phasor controlled type. The steady-state characteristics of the circuit topologies proposed are illustrated and the circuit design algorithm is described. A resonant voltage phasor controlled type high-frequency resonant inverter newly developed by using a static induction transistor (SIT) is applied as a 100-500 kHz induction-heating power supply. This paper thus refers to the results of an experiment including the optimum drive circuit of SITs.

Microprocessor control of a transistorized induction heating power supply

This paper describes the incorporation of a microprocessor based power controller into a transistorized induction heating power supply. The use of the system is illustrated by the implementation of circuit protection and power control procedures. In the design, emphasis has been placed on the efficient use of the microprocessor, a high level of interference immunity within the system, and the provision of a fault monitoring system so that the performance of the unit can be assessed continuously.

Computer simulation of a high frequency transistorized induction heating power supply

High frequency induction heating power supplies using power MOSFETs are now commercially available. The results of computer simulation of commercial units using an adaptation of SPICE are given and comparison made with practical waveforms.

Computer simulation of a high frequency transistorized induction heating power supply

Computer simulation of a high frequency transistorized induction heating power supply

A voltage fed transistorized induction heating power supply

Abstract A prototype voltage fed MOSFET power supply for high frequency induction heating applications is described. Special emphasis is given to the practicalities of paralleling MOSFETs under these conditions, the protection circuitry required, and the use of PWM as a means of power control.

Voltage-fed transistorised induction heating power supply

A prototype voltage-fed MOSFET power supply for highfrequency induction heating applications is described. Special emphasis is given to the protection circuitry required.

Design of Matching Circuitry for 100-kHz MOSFET Induction Heating Power Supply

This paper is concerned with the design of matching circuitry for a full-bridge current-fed MOSFET inverter feeding a parallel resonant induction heating load. Circuit operation is explained and analyzed and a means of suppressing ringing between parasitic lead inductance and drain-source capacitance using a filter is described. Guidelines for the selection of filter components are outlined.

Computer simulation of an induction heating power supply using power MOSFETs

High-frequency induction heating power supplies using power MOSFETs are now commercially available. The results of computer simulation of commercial units using an adaptation of SPICE are given and a comparison made with practical waveforms.

Suppression of drain source ringing in 100 kHz MOSFET induction heating power supply

The letter is concerned with a full bridge, current-fed MOSFET inverter feeding a parallel resonant induction heating load. A means of suppressing ringing between parasitic lead inductance and drain source capacitance is described.

Microprocessor control of a transistorized induction-heating power supply

The incorporation of a microprocessor-based power controller into a transistorized induction-heating power supply is described. Details are given of electronic circuitry and software to implement circuit protection and simple input current and power control. Possible extensions of the system for general supervisory tasks or for process-control requirements including closed-loop workpiece temperature control are discussed.