Computer-based modeling of moving cylindrical ferromagnetic billets induction heating

2013 ◽  
Vol 33 (1/2) ◽  
pp. 273-285 ◽  
Author(s):  
Vladimir Alexeevich Prakht ◽  
Vladimir Alexandrovich Dmitrievskii ◽  
Fedor Nikitich Sarapulov ◽  
Anton Aleksandrovich Dmitrievskii ◽  
Nail Ramazanovich Safin
Keyword(s):  
Boundary Problem ◽  
Induction Heating ◽  
Phase Distribution ◽  
Supply Voltage ◽  
Algebraic Equations ◽  
Voltage Distribution ◽  
Heating Unit ◽  
Content Type ◽  
Coupled Problem ◽  
Phase Heterogeneity

Purpose – Nowadays, various software is available for simulating physical processes in induction heating. The software is often limited in its ability to simulate the billet movement, sometimes assuming uniform distribution of voltages on the inductor winding, uniformity of the physical properties of the billet, etc. The mathematical model of moving cylindrical ferromagnetic billets described in this paper takes into account the billet's movement, the billet phase heterogeneity and the nonuniformity of the supply voltage distribution in the inductor turns. The paper aims to discuss these issues. Design/methodology/approach – The research methodology is based on FEM analysis of the coupled problem, including the electromagnetic and thermal boundary problem with additional algebraic equations, using Comsol 3.5a software. Findings – The electromagnetic and temperature field in the billet and the voltage distribution on the winding turns have been calculated. The phase distribution in the billet has been predicted. Significant interaction of the nonuniformity of the supply voltage distribution, the billet's movement, the billet phase heterogeneity and side effect on the ends of the inductor have been shown. Practical implications – The results received can be used for designing the induction heating unit for moving cylindrical billets made from ferromagnetic material and improving their characteristics. Originality/value – Investigation of moving cylindrical ferromagnetic billets induction heating can be done by numerical solving the coupled problem including the electromagnetic and thermal boundary problem with additional algebraic equations for the supply voltage distribution.

scholarly journals Sensorless Control of Voltage Peaks in Class-E Single-Ended Resonant Inverter for Induction Heating Rice Cooker

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4545
Author(s):  
Yongseung Oh ◽  
Jaeeul Yeon ◽  
Jayoon Kang ◽  
Ilya Galkin ◽  
Wonsoek Oh ◽  
...  
Keyword(s):  
High Pressure ◽  
Breakdown Voltage ◽  
Induction Heating ◽  
Control Method ◽  
Supply Voltage ◽  
Bipolar Transistors ◽  
Insulated Gate Bipolar Transistors ◽  
Voltage Fluctuations ◽  
Resonant Inverter ◽  
Do So

Single-ended (SE) resonant inverters are widely used as power converters for high-pressure rice cooker induction, with 1200 V insulated-gate bipolar transistors (IGBTs) being used as switching devices for kW-class products. When voltage fluctuations occur at the input stage of an SE resonant inverter, the resonant voltage applied to the IGBT can be directly affected, potentially exceeding the breakdown voltage of the IGBT, resulting in its failure. Consequently, the resonant voltage should be limited to below a safety threshold—hardware resonant voltage limiting methods are generally used to do so. This paper proposes a sensorless resonant voltage control method that limits the increase in the resonant voltage caused by overvoltage or supply voltage fluctuations. By calculating and predicting the resonance voltage through the analysis of the resonance circuit, the resonance voltage is controlled not to exceed the breakdown voltage of the IGBT. The experimental results of a 1.35 kW SE resonant inverter for a high-pressure induction heating rice cooker were used to verify the validity of the proposed sensorless resonant voltage limiting method.

Design of the variable frequency oscillator in DC-DC converter

Circuit World ◽  
2019 ◽  
Vol 45 (2) ◽  
pp. 80-85
Author(s):  
Tian Lei ◽  
Nan Gong ◽  
Li Wang ◽  
Qin Qin Li ◽  
Heng Wei Wang
Keyword(s):  
Supply Voltage ◽  
Operating Frequency ◽  
Maximum Deviation ◽  
Variable Frequency ◽  
Cmos Process ◽  
Power Supply Voltage ◽  
Output Stage ◽  
Content Type ◽  
Oscillator Frequency ◽  
Light Load

Purpose Because of the logic delay in the converter, the minimum turn on time of the switch is influenced by the constant time. When the inductor current gets to the threshold of the chip, the control signal will delay for a period. This makes the inductor current rising with the increasing of the clock and leads to the load current out of control. Thus, this paper aims to design an oscillator with a variable frequency protection function. Design/methodology/approach This paper presents an oscillator with the reducing frequency applied in the DC-DC converter. When the converter works normally, the operating frequency of the oscillator is 1.5 MHz. So the inductor current has enough time to decay and prevent the power transistor damaging. After the abnormal condition, the converter returns to the normal operating mode automatically. Findings Based on 0.5 µm CMOS process, simulated by the HSPICE, the simulation results shows that the frequency of the oscillator linearly decreases from 1.5 MHz to 380 KHz when the feedback voltage less than 0.2 V. The maximum deviation of the oscillator frequency is only 6 per cent from −50°C to 125°C within the power supply voltage of 2.7-5.5 V. Originality/value When the light load occurs at the output stage, the oscillator frequency will decrease as the load voltage drops. The test results shows that when the circuit works in the normal condition, the oscillator frequency is 1.5 MHz. When the load decreased, the operating frequency is dropped dramatically.

A robust cascaded controller for DC-DC Boost and Cuk converters

2017 ◽  
Vol 14 (5) ◽  
pp. 459-466 ◽  
Author(s):  
Fiaz Ahmad ◽  
Akhtar Rasool ◽  
Esref Emre Ozsoy ◽  
Asif Sabanoviç ◽  
Meltem Elitas
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Supply Voltage ◽  
Load Resistance ◽  
Switching Frequency ◽  
Content Type ◽  
Mode Control ◽  
Control Scheme ◽  
Equivalent Control ◽  
Discontinuous Nature

Purpose This paper aims to propose a robust cascaded controller based on proportional-integral (PI) and continuous sliding mode control. Design/methodology/approach Cascaded control structure is an attractive control scheme for DC-DC power converters. It has a two-loop structure where the outer loop contains PI controller and the inner loop uses sliding mode control (SMC). This structure thus combines the merits of both the control schemes. However, there are some issues that have prohibited its adoption in industry, the discontinuous nature of SMC which leads to variable switching frequency operation and is hard to realize practically. This paper attempts to overcome this issue by changing the discontinuous functionality of SMC to continuous by utilizing the concept of equivalent control. Findings The robustness of the controller designed is verified by considering various cases, namely, ideal case with no uncertainties, sudden variation of input supply voltage, load resistance, reference voltage, circuit-parameters and for noise disturbance. The controller effectiveness is validated by simulating the DC-DC boost and Cuk converters in SimPowerSystems toolbox of MATLAB/Simulink. It is shown that the performance of the proposed controller is satisfactory, and both reference output voltage and inductor current are tracked with little or no sensitivity to disturbances. Originality/value The results for various scenarios are interesting and show that the controller works quite satisfactorily for all the simulated uncertainties.

Solution of third-order Emden–Fowler-type equations using wavelet methods

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Arshad Khan ◽  
Mo Faheem ◽  
Akmal Raza
Keyword(s):  
Nuclear Reactions ◽  
Approximate Solutions ◽  
Algebraic Equations ◽  
Third Order ◽  
Content Type ◽  
Resolution Level ◽  
The Stability ◽  
Comparison Of The Results ◽  
Wavelet Methods ◽  
Nonlinear Nature

Purpose The numerical solution of third-order boundary value problems (BVPs) has a great importance because of their applications in fluid dynamics, aerodynamics, astrophysics, nuclear reactions, rocket science etc. The purpose of this paper is to develop two computational methods based on Hermite wavelet and Bernoulli wavelet for the solution of third-order initial/BVPs. Design/methodology/approach Because of the presence of singularity and the strong nonlinear nature, most of third-order BVPs do not occupy exact solution. Therefore, numerical techniques play an important role for the solution of such type of third-order BVPs. The proposed methods convert third-order BVPs into a system of algebraic equations, and on solving them, approximate solution is obtained. Finally, the numerical simulation has been done to validate the reliability and accuracy of developed methods. Findings This paper discussed the solution of linear, nonlinear, nonlinear singular (Emden–Fowler type) and self-adjoint singularly perturbed singular (generalized Emden–Fowler type) third-order BVPs using wavelets. A comparison of the results of proposed methods with the results of existing methods has been given. The proposed methods give the accuracy up to 19 decimal places as the resolution level is increased. Originality/value This paper is one of the first in the literature that investigates the solution of third-order Emden–Fowler-type equations using Bernoulli and Hermite wavelets. This paper also discusses the error bounds of the proposed methods for the stability of approximate solutions.

An efficient coupled pressure–velocity solver for three-dimensional injection molding simulation using Schur complement preconditioned FGMRES

2019 ◽  
Vol 36 (4) ◽  
pp. 1101-1120
Author(s):  
Xiang Liu ◽  
Fei Guo ◽  
Yun Zhang ◽  
Junjie Liang ◽  
Dequn Li ◽  
...  
Keyword(s):  
Injection Molding ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Schur Complement ◽  
Gradient Term ◽  
Content Type ◽  
Coupled Problem ◽  
Parallel Performance ◽  
Injection Molding Simulation ◽  
Fully Coupled

Purpose The purpose of this paper is to develop a coupled approach to solve the pressure–velocity-coupled problem efficiently in the three-dimensional injection molding simulation. Design/methodology/approach A fully coupled pressure–velocity algorithm is developed to solve the coupled problem, by treating the pressure gradient term implicitly. And, the Schur complement preconditioned FGMRES is applied to decompose the resulting coupled pressure–velocity equation into pressure and velocity subsystems. Then, BoomerAMG is adopted to solve the pressure subsystem, and block Jacobi preconditioned FGMRES is applied to the velocity subsystem. Findings According to the several experiments, the fully coupled pressure–velocity algorithm was demonstrated to have faster convergence than the traditional SIMPLE algorithm, and the calculating time was reduced by up to 70 per cent. And, the Schur complement preconditioned FGMRES worked more efficiently than block Gauss–Seidel preconditioned FGMRES, block-selective AMG and AMG with block ILU(0) smoother and could take at least 47.4 per cent less time. The proposed solver had good scalability for different-size problems, including various cases with different numbers of elements. It also kept good speedup and efficiency in parallel performance. Originality/value A coupled solver has been proposed to effectively solve the coupled problem in the three-dimensional injection molding simulation, which is more robust and efficient than existing methods.

Ultra-low-power time-efficient circuitry of dual comparator/amplifier for SAR ADC by CMOS technology

Circuit World ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 183-192
Author(s):  
Muhammad Yasir Faheem ◽  
Shun'an Zhong ◽  
Xinghua Wang ◽  
Muhammad Basit Azeem
Keyword(s):  
Low Power ◽  
Energy Efficient ◽  
Supply Voltage ◽  
Main Idea ◽  
Cost Effective ◽  
Cmos Technology ◽  
Sar Adc ◽  
Ultra Low Power ◽  
Content Type ◽  
Analogue To Digital

Purpose Successive approximation register (SAR) analogue to digital converter (ADC) is well-known with regard to low-power operations. To make it energy-efficient and time-efficient, scientists are working for the last two decades, and it still needs the attention of the researchers. In actual work, there is no mechanism and circuitry for the production of two simultaneous comparator outputs in SAR ADC. Design/methodology/approach A small-sized, low-power and energy-efficient circuitry of a dual comparator and an amplifier is presented, which is the most important part of SAR ADC. The main idea is to design a multi-dimensional circuit which can deliver two quick parallel comparisons. The circuitry of the three devices is combined and miniaturized by introducing a lower number of MOSFET’s and small-sized capacitors in such a way that there is no need for any matching and calibration. Findings The supply voltage of the proposed comparator is 0.7 V with the overall power consumption of 0.257mW. The input and clock frequencies are 5 and 50 MHz, respectively. There is no requirement for any offset calibration and mismatching concerns due to sharing and centralization of spider-latch circuitry. The total offset voltages are 0.13 0.31 mV with 0.3VDD to VDD. All the components are small-sized and miniaturized to make the circuit cost-effective and energy-efficient. The rise and response time of comparator is around 100 ns. SNDR improved from 56 to 65 dB where the input-referred noise of an amplifier is 98mVrms. Originality/value The proposed design has no linear-complexity compared with the conventional comparator in both modes (working and standby); it is ultimately intended and designed for 11-bit SAR ADC. The circuit based on three rapid clock pulses for three different modes includes amplification and two parallel comparisons controlled and switched by a latch named as “spider-latch”.

Design of power converters for induction heating applications taking advantage of wide-bandgap semiconductors

2017 ◽  
Vol 36 (2) ◽  
pp. 483-488 ◽  
Author(s):  
Oscar Lucia ◽  
Hector Sarnago ◽  
José M. Burdio
Keyword(s):  
Induction Heating ◽  
Wide Bandgap ◽  
Power Supplies ◽  
Disruptive Technology ◽  
Content Type ◽  
Heating Systems ◽  
Future Design ◽  
Bandgap Semiconductors ◽  
Heating Technology ◽  
Selection Of

Purpose Wide-bandgap (WBG) semiconductors have emerged as a disruptive technology in the power electronics sphere. This paper aims to analyse and discuss the importance for induction heating systems and gives some examples and highlights some future design trends and perspectives. Design/methodology/approach The benefits of WBG semiconductors are reviewed with a special emphasis on induction heating applications. Findings WBG devices enable the design of higher-performance induction heating power supplies. A significant selection of the reported converters is discussed, highlighting the benefits of this technology. Originality/value This paper highlights the benefits of WBG semiconductors and their potential to change and improve induction heating technology in the next years.

Impact of supply voltage variations on external magnetic field emitted by induction machines

2017 ◽  
Vol 36 (3) ◽  
pp. 692-701
Author(s):  
Mohamed Omar Younsi ◽  
Olivier Ninet ◽  
Fabrice Morganti ◽  
Jean-Philippe Lecointe ◽  
Farid Zidat ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Circuit ◽  
Supply Voltage ◽  
Induction Machines ◽  
Tangential Component ◽  
Content Type ◽  
Internal Fault ◽  
Torque Estimation ◽  
Numerical Finite Element

Purpose This paper aims to study the influence of supply voltage variations on the external magnetic field emitted by grid-powered induction machines (IMs). Design/methodology/approach Two models are developed in the paper to analyse, for different supply voltage values, the influence of the variations of the magnetizing voltage for which there is a link with the tangential component of the external flux. The first is an analytical model based on the IM single-phase-equivalent circuit with variable magnetizing reactance to take into account the saturation of the magnetic circuit. The second is a numerical finite element simulation to model the same phenomenon. Results of both models are analysed with experimental measures of the external flux. Findings The study shows that the amplitude of the external field strongly depends on supply voltage values. Research limitations/implications The investigation is mainly focused on the tangential component of the external magnetic field which is of high importance concerning the applicability of non-invasive methods of diagnosis, as electromagnetic torque estimation developed by the authors or internal fault determination. Originality/value The originality of the paper concerns the characterization of the external flux with the supply voltage for IMs. It is shown that the magnetic circuit radiates external flux differently with the load and with the supply voltage.

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