Dongsu Lee

Numerical Design Compatibility of Induction Motor With Respect to Voltage and Current Sources

In this paper, the optimal driving point of induction motor is selected for guaranteeing torque production, which is fed by d-q current combination, and numerical design compatibility employing current source FEM is verified via comparison with the one employing voltage source method. In particular, vector control considering voltage and current constraints has been implemented numerically with FEM when selecting the optimal driving point. Moreover, comparative analysis is performed for the design results, such as magnetic saturation and iron loss, according to driving points selected in designing procedure. With the identified results, the design compatibility of FEM engaged with the current source is validated with comparison of the one obtained by FEM and equivalent circuit method engaged with the voltage source.

Intelligent MADS With Clustering and Elastic Net and Its Application to Optimal Design of Interior PM Synchronous Machines

Optimal design of the electric machines is interlinked with the optimization algorithm for obtaining the quantitative optimum and numerical analysis of electric machines for the objective function. The optimization algorithm is required to evaluate the objective function minimal times since numerical analysis of the electric machines consumes a lot of time. In this paper, intelligent MADS with a clustering and elastic net is newly adopted for the optimal design of electric machines to raise the reliability of the global optimization and fast convergence time. In particular, the proposed algorithm is employed to the optimal design of the interior permanent-magnet PM synchronous machine minimizing torque ripples, which has been regarded as one of the complicated design problems.

Variable Mesh Adaptive Direct Search Algorithm Applied for Optimal Design of Electric Machines Based on FEA

Optimal design of electric machine based on finite element analysis (FEA) is characterized with the nonlinear magnetic saturation, which causes the much longer computation time for maintaining the high accuracy. In order to compensate the excessive computation time due to FEA and guarantee the reliable convergence to global optimum, variable mesh adaptive direct search (VMADS) is newly implemented with multi-start in this paper. Effectiveness of VMADS has been verified through a benchmark function. In particular, the proposed algorithm has been employed to optimal design of interior permanent magnet synchronous machine (IPMSM) for maximum torque per ampere (MTPA), of which design objective should be evaluated by FEA for better accuracy.

Performance evaluation of coreless axial flux permanent magnet wind generator

Numerical design characteristics of coreless axial flux permanent magnet synchronous generator (AFPMSG) for wind turbine have been investigated in terms of output voltage and current, total harmonic distortion, efficiency, and inductance. The 3 .2 kW coreless AFPMSG is analyzed using 3D nonlinear finite element method.

Optimal Design of Interior PM Synchronous Machines Using Randomly Guided Mesh Adaptive Direct Search Algorithm

Interior PM Synchronous Machines (IPMSM) has characteristic of nonlinear magnetic saturation and many local optimal, have been focused on reducing computation time [1]-[2]. Hence, randomly guided MADS (Mesh Adaptive Direct Search) is newly implemented to reducing the excessive computation time. Optimization capability of the proposed randomly guided MADS is validated through two benchmark functions. In particular, it has been forwarded to optimal design of IPMSM for maximizing Maximum Torque per Ampere (MTPA) based on FEA (Finite Element Analysis).

Min-Max Univariate Dynamic Encoding Algorithm for Searches (uDEAS) and Its Application to Optimal Design of Electric Machines

Optimal design of Interior Permanent Magnet Synchronous Machines (IPMSM) is to obtain the global design optimum in association with the characteristic analysis investigating nonlinear magnetic saturation based on Finite Element Analysis (FEA). Since characteristic analysis occupies most part of the convergence time, the number of objective function must be called minimally. Hence, in this paper, MuDEAS is newly implemented in order to compensate the excessive computation time and the reliability of convergence to the global optimum. MuDEAS has been verified through a benchmark function and applied to the optimal design of IPMSM for maximizing Maximum Torque Per Ampere (MTPA) indentified with FEA.

NUMERICAL ANALYSIS ON THE MECHANICAL PROPERTIES OF ORGANIC THIN FILM TRANSISTOR

The organic thin film transistor (OTFT) on flexible substrate electroplated electrodes has many advantages as in the fabrication of low cost sensors, e-paper, smart cards, and flexible displays. In this study, we simulated the mechanical and electrical characteristics of the OTFT with various voltage conditions by using COMSOL. The model consisting of a channel, source and drain was employed to investigate the temperature distribution and thermal stress concentration. The channel length is 40 µm and the voltage ranged between -20V and -40V. The OTFT was fabricated using pentacene as a semiconducting layer and electroplated Ni as a gate electrode. Mechanical properties of the fabricated OTFT were characterized by thermal stress which was predicted with the result of stress distribution.