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Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

The purpose of this paper is to describe a technique for modeling transformer internal faults using transmission line modeling (TLM) method. In this technique, a model for simulating a two winding single phase transformer is modified to be suitable for simulating an internal fault in both windings.

TLM technique is mainly used for modeling transformer internal faults. This was first developed in early 1970s for modeling two‐dimensional field problems. Since, then, it has been extended to cover three dimensional problems and circuit simulations. This technique helps to solve integro‐differential equations of the analyzed circuit. TLM simulations of a single phase transformer are compared to a custom built transformer in laboratory environment.

It has been concluded from the real time studies that if an internal fault occurs on the primary or secondary winding, the primary current will increase a bit and secondary current does not change much. However, a very big circulating current flows in the shorted turns. This phenomenon requires a detailed modeling aspect in TLM simulations. Therefore, a detailed inductance calculation including leakages is included in the simulations. This is a very important point in testing and evaluating protective relays. Since, the remnant flux in the transformer core is unknown at the beginning of the TLM simulation, all TLM initial conditions are accepted as zero.

The modeling technique presented in this paper is based on a low frequency (up to a few kHz) model of the custom‐built transformer. A detailed capacitance model must be added to obtain a high‐frequency model of the transformer. A detailed arc model, aging problem of the windings will be applied to model with TLM + finite element method.

Using TLM technique for dynamical modeling of transformer internal faults is the main contribution. This is an extended version of an earlier referenced paper of the authors and includes inductance calculation, leakages calculation, and BH curve simulation while the referenced paper only includes piecewise linear inductance values. This modeling approach may help power engineers and power system experts understand the behavior of the transformer under internal faults.

Imperfections in manufacturing processes may cause unwanted connections (faults) that are added to the nominal, “golden”, design of an electronic circuit. By fault simulation one simulates all situations. Normally this leads to a large list of simulations in which for each defect a steady-state (direct current (DC)) solution is determined followed by a transient simulation. The purpose of this paper is to improve the robustness and the efficiency of these simulations.

Determining the DC solution can be very hard. For this the authors present an adaptive time-domain source stepping procedure that can deal with controlled sources. The method can easily be combined with existing pseudo-transient procedures. The method is robust and efficient. In the subsequent transient simulation the solution of a fault is compared to a golden, fault-free, solution. A strategy is developed to efficiently simulate the faulty solutions until their moment of detection.

The paper fully exploits the hierarchical structure of the circuit in the simulation process to bypass parts of the circuit that appear to be unaffected by the fault. Accurate prediction and efficient solution procedures lead to fast fault simulation.

The fast fault simulation helps to store a database with detectable deviations for each fault. If such a detectable output “matches” a result of a product that has been returned because of malfunctioning it helps to identify the subcircuit that may contain the real fault. One aims to detect as much as possible candidate faults. Because of the many options the simulations must be very efficient.

This paper aims to introduce a novel four-dimensional hyper-chaotic system with different hyper-chaotic attractors as certain parameters vary. The typical dynamical behaviors of the new hyper-chaotic system are discussed in detail. The control problem of these hyper-chaotic attractors is also investigated analytically and numerically. Then, two novel electronic circuits of the proposed hyper-chaotic system with different parameters are presented and realized using physical components.

The adaptive control method is derived to achieve chaotic synchronization and anti-synchronization of the novel hyper-chaotic system with unknown parameters by making the synchronization and anti-synchronization error systems asymptotically stable at the origin based on Lyapunov stability theory. Then, two novel electronic circuits of the proposed hyper-chaotic system with different parameters are presented and realized using physical components. Multisim simulations and electronic circuit experiments are consistent with MATLAB simulation results and they verify the existence of these hyper-chaotic attractors.

Comparisons among MATLAB simulations, Multisim simulation results and physical experimental results show that they are consistent with each other and demonstrate that changing attractors of the hyper-chaotic system exist.

The goal of this paper is to construct a new four-dimensional hyper-chaotic system with different attractors as certain parameters vary. The adaptive synchronization and anti-synchronization laws of the novel hyper-chaotic system are established based on Lyapunov stability theory. The corresponding electronic circuits for the novel hyper-chaotic system with different attractors are also implemented to illustrate the accuracy and efficiency of chaotic circuit design.

The purpose of this paper is to present an experimental setup for the verification of coupled electromagnetic field‐circuit simulation, called TESTCASE. By means of simple and well‐defined geometries, the comparison of different coupling approaches among each other and with measurements should be possible.

The physical setup consists of a C‐core in conjunction with a reluctance rotor. The TESTCASE is designed to work in static operation and with motion induced voltage.

Simulation results using different approaches as well as measurement results are presented. Practical issues in measurement and simulation are discussed. It was found that particular care has to be taken concerning the modeling of the air around the TESTCASE structure.

With the proposed approach, it is possible to evaluate the coupled field circuit problem on a defined and well‐known geometry. Simulation results can be compared to measurements.

The ability to simulate the effects of process technology on final product circuits has become virtually indispensable in modern VLSI production. It is especially significant as a toot for controlling parametric yield by appropriate design centering and in determining the sensitivity of the electrical parameters to process control tolerances. The system demands the combined use of process simulation device simulation and circuit simulation all three of which rely heavily on computationally intensive numerical solution of partial differential equations. The severe computational overhead involved in ‘technology simulation TCAD)’ means it is generally expensive and limits the scope of statistical design centering and optimisation, which depend on a large number of simulations. A compromise solution is often resorted to by limiting simulation to one or two spatial dimensions, replacing numerical simulation by analytical approximations as implemented in the statistical process simulator: FABRICS 11, or combining numerical and analytical models as in the process/device simulator PRIDE.) This paper addresses the problem of simpler, higher efficiency TCAD evaluation by restricting the domain of the simulation and approximating the process/device characteristic relationship by a set of simple, computationally efficient empirical equations. These equations offer a high speed solution at the expense of decreasing accuracy away from the nominal process centre. Referred to as a ‘response surface model’, it is generated using the results of a small number of statistically designed TCAD simulations. As the process sample is centred around the nominal design parameters, the model can be used to statistically analyze the effects of process perturbations.

The purpose of this paper is to review the mutual coupling of electromagnetic fields in the magnetic vector potential formulation with electric circuits in terms of (modified) nodal and loop analyses. It aims for an unified and generic notation.

The coupled formulation is derived rigorously using the concept of winding functions. Strong and weak coupling approaches are proposed and examples are given. Discretization methods of the partial differential equations and in particular the winding functions are discussed. Reasons for instabilities in the numerical time domain simulation of the coupled formulation are presented using results from differential-algebraic-index analysis.

This paper establishes a unified notation for different conductor models, e.g. solid, stranded and foil conductors and shows their structural equivalence. The structural information explains numerical instabilities in the case of current excitation.

The presentation of winding functions allows to generically describe the coupling, embed the circuit equations into the de Rham complex and visualize them by Tonti diagrams. This is of value for scientists interested in differential geometry and engineers that work in the field of numerical simulation of field-circuit coupled problems.

Waveform relaxation has potential to overcome problem of excessive computer run times which are necessary for simulation of larger circuits with the use of existing simulators. One of the attractive features of waveform relaxation is its suitability for parallel implementation. Amount of data necessary for interchange between parallel processors after each iteration influences the overall performance of simulation. Method of integration based on Chebyshev series provides for representation of solutions in the most compact form which makes it very attractive for parallel implementations. This paper presents some results of numerical experiments with the spectral integration applied in the relaxation framework to a number of MOS circuits.

Many electric circuits feature some type of non-linearity of their used devices. Non-linear resistors or inductors could be typical examples. Also, all semiconductor devices are in their nature non-linear ones. The simulation models are very important parts of the design of the devices in various fields of industry. Multiply (multiple) simulation, verified by the measurement on the physical sample, help to improve the converter design by understanding the current and voltage behavior of non-linear elements. The paper aims to discuss these issues.

Mathematical model of LCTLC inverter was made. Fictitious exciting function was applied on LCTLC inverter model. The non-linear inductance with the real core EFD model has been created and consequentially used for MatLab simulation experiments. MatLab and OrCAD/PSpice simulation results were compared with experimental measurements carried out on physical sample.

The authors have found how to simulate non-linear resonant circuits within mathematical apparatus using fictitious exciting function method. The authors provided comparisons between proposed simulation mathematical model and relevant physical sample. Multiply simulations can help to improve the converter design by understanding the current and voltage behavior of non-linear elements.

The proposed method is applicable for simulation purposes. The only limitation is that MatLab model does not include hysteresis curve of the core, therefore it has to be modeled.

The design of power supplies (switched mode power supplies, UPS and resonant inverter).

Research in the area of behaviors of non-linear components in resonant circuits.

The purpose of this paper is to improve the stability of high voltage DC power supply and reduce the ripple.

The study was conducted using the simulation analysis model and numerical calculation.

By increasing the output arm capacitance, the expression of ripple and times of the output arm capacitance and the auxiliary arm capacitance is derived. The output ripple is determined by the value of the output arm capacitance. Finally, the correctness of the method and the formula are verified using circuit simulation.

This paper presents a method to improve the power supply stability.