Parameter Identification Method for a 3-phase Induction Heating System

This paper describes a new method for the on-line parameter estimation of an induction heating system. Simulations and experiments are presented in order to measure its impedance matrix for more exact control in closed loop. In previous papers, various parameter identification methods including off-line methods were introduced and compared for current inverters. It has been demonstrated that parameter identification is necessary to achieve good control of the inductor currents. A “pseudo-energy” method for a simple and fast implementation is compared to a classical “V/I with phase shift” method. They are experienced on a reduced power 3-phase coupled resonant system supplied with voltage inverters with satisfying results

Data-driven discovery of the heat equation in an induction machine via sparse regression

Discovery of natural laws through input-output data analysis has been of considerable interest during the past decade. Various approach among which the increasingly growing body of sparsity-based algorithms have been recently proposed for the purpose of free-form system identification. There has however been limited discussion on the performance of these approaches when applied on experimental datasets. The aim of this paper is to study the capability of this technique for identifying the heat equation as the natural law of heat distribution from experimental data, obtained using a Totally-Enclosed-Fan-Cooled (TEFC) induction machine, with and without active cooling. The results confirm the usefulness of the algorithm as a method to identify the underlying natural law in a physical system in the form of a Partial Differential Equation (PDE)

Multi phase system for metal disc induction heating: modelling and RMS current control

This paper presents a multi phase induction system modelling for a metal disc heating and further industrial applications such as hot strip mill. An original architecture, with three concentric inductors supplied by three resonant current inverters leads to a reduced element system, without any coupling transformers, phase loop, mobile screens or mobile magnetic cores as it could be found in classical solutions. A simulation model is built, based on simplified equivalent models of electric and thermal phenomena. It takes into account data extracted from Flux2D® finite element software, concerning the energy transfer between the inductor currents and the piece to be heated. It is implemented in a versatile software PSim, initially dedicated to power electronic. An optimization procedure calculates the optimal supply currents in the inverters in order to obtain a desired power density profile in the work piece. The paper deals with The simulated and experimental results are compared in open-loop and closed loop. The paper ends with a current control method which sets RMS inductor currents in continuous and digital conditions

Assessment of the infrared welding process for a carbon fabric reinforced pps

This study assesses the use of infrared welding for a carbon fabric reinforced polyphenylene sulphide. Infrared light is used in order to melt the thermoplastic matrix of the two components, after which they are joined together under pressure. Welding parameters such as power of the infrared lights, heating time, contact pressure and consolidation time are optimised. Next, a series of joints is fabricated and the interlaminar behaviour of the weld is characterised. For the mode I behaviour, the Double Cantilever Beam test (DCB) is considered, whereas for mode II crack growth, the End Notch Flexure test (ENF) is used. Results are compared to the interlaminar behaviour of the base material. It can be concluded that the infrared process proves very interesting for the material under study and that joints can be manufactured with fracture toughness values equal or higher to the base material, both for mode I and mode II, but that a slightly different failure behaviour manifests itself

Kinetics of phase transition from lamellar to hexagonally packed cylinders for a triblock copolymer in a selective solvent

We examined the kinetics of the transformation from the lamellar (LAM) to the hexagonally packed cylinder (HEX) phase for the triblock copolymer, polystyrene-b-poly (ethylene-co-butylene)-b-polystyrene (SEBS) in dibutyl phthalate (DBP), a selective solvent for polystyrene (PS), using time-resolved small angle x-ray scattering (SAXS). We observe the HEX phase with the EB block in the cores at a lower temperature than the LAM phase due to the solvent selectivity of DBP for the PS block. Analysis of the SAXS data for a deep temperature quench well below the LAM-HEX transition shows that the transformation occurs in a one-step process. We calculate the scattering using a geometric model of rippled layers with adjacent layers totally out of phase during the transformation. The agreement of the calculations with the data further supports the continuous transformation mechanism from the LAM to HEX for a deep quench. In contrast, for a shallow quench close to the OOT we find agreement with a two-step nucleation and growth mechanism

Electromagnetic containerless processing requirements and recommended facility concept and capabilities for space lab

Containerless melting, reaction, and solidification experiments and processes which potentially can lead to new understanding of material science and production of new or improved materials in the weightless space environment are reviewed in terms of planning for spacelab. Most of the experiments and processes discussed are amenable to the employment of electromagnetic position control and electromagnetic induction or electron beam heating and melting. The spectrum of relevant properties of materials, which determine requirements for a space laboratory electromagnetic containerless processing facility are reviewed. Appropriate distributions and associated coil structures are analyzed and compared on the basis of efficiency, for providing the functions of position sensing, control, and induction heating. Several coil systems are found capable of providing these functions. Exchangeable modular coils in appropriate sizes are recommended to achieve the maximum power efficiencies, for a wide range of specimen sizes and resistivities, in order to conserve total facility power

Feasibility study of fusion bonding for carbon fabric reinforced Polyphenylene Sulphide by hot-tool welding

In recent years, there is a growing interest in joining techniques for thermoplastic composites as an alternative to adhesive bonding. In this article, a fusion bonding process called hot-tool welding is investigated for this purpose and the used material is a carbon fabric reinforced polyphenylene sulphide. The welds are first observed through a microscope, after which the quality is experimentally assessed using a short three-point bending setup. A comparison is made between the welded specimens and the equivalent hot pressed specimens. It can be concluded that the hot-tool welding process is very promising for the welding of material under study and that the short three-point bending setup proves interesting for evaluating bonds between composite specimens

Furnace and support equipment for space processing

A core facility capable of performing a majority of materials processing experiments is discussed. Experiment classes are described, the needs peculiar to each experiment type are outlined, and projected facility requirements to perform the experiments are treated. Control equipment (automatic control) and variations of the Czochralski method for use in space are discussed