Search

In a linear eddy current system excited by a current source, a high-order frequency sensitivity is derived in variational formulation instead of as a discretized state equation. An analytic sensitivity formulation of order n is obtained by sequentially differentiating the variational eddy current system with respect to angular frequency. The high-order frequency sensitivity is implemented through a commercial finite element method. A frequency sensitivity analysis conducted based on two numerical examples verifies the results. [ABSTRACT FROM AUTHOR]

This article proposes a continuum-sensitivity-based method to obtain the optimal design for an interior permanent magnet synchronous motor (IPMSM). Compared with the finite difference method, the continuum sensitivity analysis shortens the computation time significantly when there are numerous design variables. We combine the continuum sensitivity with the shape constraint so that both the shape and the size can be optimized simultaneously and within a short time. This proposed design optimization method is applied to IPMSM rotor design, and its feasibility is verified. The proposed method is expected to be effective for various design problems that require the shape and the size to be optimized simultaneously. [ABSTRACT FROM AUTHOR]

This paper proposes dot sensitivity analysis of a current region for topology optimization. A continuum shape sensitivity formula is employed to derive a dot sensitivity formula in a simple closed form. The derived dot sensitivity formula provides the information on where the current dots should be created for topology optimization. This is necessary to generate the current dots in a vacant region of the design domain. Because this dot sensitivity analysis can obtain various topologies of material distribution, the possibility of local optimum convergence is reduced. Furthermore, because this dot sensitivity analysis does not require a specific initial design, its numerical implementation is simple. This dot sensitivity method is combined with the level set method to perform topology optimization. To demonstrate the usefulness of the proposed method, it is applied to two optimization problems of magnetic resonance imaging. [ABSTRACT FROM AUTHOR]

In this paper, a dot sensitivity analysis is proposed for the topology optimization of dielectric materials in an electrostatic system. Dot sensitivity formula is analytically derived in closed form using the continuum shape sensitivity formula. The level set method is used for evolving the geometry in the topology optimization. As the dot sensitivity analysis can generate new material in a vacant region, it does not require an initial design for the dielectric material and widens the design space. Two numerical examples are tested to show the usefulness of dot sensitivity analysis. [ABSTRACT FROM AUTHOR]

In this paper, the hole sensitivity analysis is proposed for topology optimization in the electrostatic system. The hole sensitivity formula is derived using the virtual hole concept and the continuum shape sensitivity. Since the derived formula is expressed as a closed form, it is simple and easy to implement and apply to real problems. The hole sensitivity analysis provides information for topology variation. The geometrical expression of the topology variation is obtained using the level set method. Two numerical examples are tested to show the usefulness of the hole sensitivity analysis. [ABSTRACT FROM AUTHOR]

In this paper, the motion of conductive particles is modeled and analyzed using a coupled equation. A neutral conductive particle obtains charge when it comes into contact with an electrode. The forces acting on a particle consist of electric, drag, and gravitational forces. When the electric force is dominant over the other forces, a particle lifts up toward the upper electrode. The electric force on a particle is calculated using surface charge distribution, which is analyzed using the finite-element method. The dominant forces on the particles are used as a driving force in Newton’s motional equation to analyze a particle motion. The analysis results show that the total charge, which enables the particle to lift off, is calculated using the coupled equation with respect to the applied voltage. The experiment using a spherical conductive particle is conducted, and the experiment result is compared with the numerical one to validate the numerical method. [ABSTRACT FROM AUTHOR]

A new design method for topology and shape optimization to preserve high-voltage systems is proposed. The level set technique for the topology optimization is employed with the finite-element method. For the velocity field in the level set equation, the continuum sensitivity formula is used for accurate information of the electric field effect on the topology and shape variation. This technique is applied to three practical examples and the optimum designs of insulating dielectric for the systems are obtained. The optimum designs could suppress troubles, such as thermal deterioration or electrical breakdown, in the systems. [ABSTRACT FROM PUBLISHER]

In this paper, hole sensitivity formula is analytically derived for topology optimization in magnetostatic system. With the concept of virtual hole, the hole sensitivity is obtained using continuum shape sensitivity. To demonstrate the validity of the hole sensitivity, topology optimization of synchronous reluctance motor is tested. Since the hole sensitivity formula is represented only with electromagnetic field, it is easily implemented for topology optimization. [ABSTRACT FROM PUBLISHER]