Sang-Baeck Yoon

Analysis of forces in a short primary type and a short secondary type permanent magnet linear synchronous motor

This paper presents the analysis of the static thrust, the detent force and the normal force of a permanent magnet linear synchronous motor (PMLSM) using the finite element method (FEM). The forces of a short primary type PMLSM and a short secondary type PMLSM are compared. To reduce the force ripple, the characteristics according to the width of the PM and the effect of the primary core shape were studied.

Analysis of PMLSM using three dimensional equivalent magnetic circuit network method

This paper presents characteristics of a permanent magnet linear synchronous motor (PMLSM) considering lateral leakage flux and lateral displacement. In order to analyze the PMLSM with large air gap and finite width, a new three dimensional equivalent magnetic circuit network method (3D EMC) is introduced, which supplements the magnetic equivalent circuit by using numerical techniques. It can model flux ripple three-dimensionally by the teeth and slot structure of the PMLSM, and can take nonlinear magnetic phenomenon into account, which results from using the distributed magnetic circuit parameter, permeance. The analysis considering lateral flux and lateral displacement in the PMLSM which is problematic in 3D is performed using 3D EMC and is compared with the experimental value.

The fault diagnosis of rotor bars in squirrel cage induction motors by time-stepping finite element method

This paper presents a fault diagnosis of the rotor bars in squirrel cage induction motors. The defective rotor bars such as broken bars and high resistance are detected by analyzing the induced current in the coil caused by reluctance variation when the rotor is moving. In the analysis, the time stepping finite element method is used where the electromagnetic and circuit equations are coupled and the rotor movement is considered by automatic subdivision of air gap meshes. By the proposed method, various rotor fault conditions are simulated. The experimental results show that the analysis method is useful to detect rotor fault conditions.

Robust shape optimization of electromechanical devices

This paper presents the robust shape optimization of electromechanical devices considering the uncertainties of design variables based on numerical optimization technique and finite element method (FEM). In the formulation of robust optimization, the multiobjective function is composed of the mean and the standard deviation of original objective function, while the constraints are supplemented by adding a penalty term to the original constraints. The sequential quadratic programming (SQP) is applied to solve the robust optimization problem. The results of robust shape optimization considering manufacturing errors are compared with those of conventional shape optimization.

A Method Of Optimal Design Of Single-sided Linear Induction Motor For Transit

An optimal design method for a single-sided linear induction motor (SLIM) for transit applications is described. The authors propose a method which determines the overall parameters of an SLIM for transit using only the rated mechanical output. When the optimization is carried out, the slot depth is used as the initial value so that the exact slot depth is calculated iteratively from the circuit equation. The optimization problem of a SLIM design is approached by use of the sequential quadratic programming (SQP). The influence of design variables is analyzed by the rated thrust and the rated velocity respectively.

Shape Optimization of Solenoid Actuator Using the Finite Element Method And Numerical Optimization Technique

This paper presents shape optimization of moving core type solenoid actuator driven by DC source. 3-D axisymmetric finite element method (FEM) is used for the electromagnetic field analysis and saturation effect of the magnetic material is considered. The mechanical dynamic equation and electrical circuit equation are also coupled. In the dynamic characteristic by FEM, we adapt a moving line technique to save computation time and to perform the process efficiently. Among the optimization algorithms, sequential quadratic programming (SQP) is carried out for the shape optimization. A good performance of optimized solenoid actuator has been verified through the experiment.

Dynamic Analysis Of A Reciprocating Linear Actuator For Gas Compression Using Finite Element Method

This paper presents the dynamic analysis of a reciprocating actuation system based on moving magnet actuator for gas compression. For the analysis of the linear actuator, an axisymmetric finite element method (FEM) considering the saturation effect of the magnetic material is used, and electrical circuit equation, mechanical dynamic equation and pressure dynamics are coupled. In the FE analysis, we adopt a moving line technique to save computation time and to perform the process efficiently. The pressure dynamics of the gas in the compressor is modeled by using the law of thermodynamics. The analysis results compare fairly well with experimental ones.

Analysis and optimal design of the slit type low speed linear induction motor

This paper describes the analysis and optimal design of the slit type linear induction motor (LIM) with transformed secondary reaction plate. In an analysis method, we select a unit region corresponding to a single secondary slit pitch and the presence of the rest of the secondary distribution is implied by specifying the pitch boundary condition. From the analysis method, we construct the equivalent circuit and analyze the characteristics of the LIM. Using the sequential quadrature programming (SQP), the optimum design variables are derived. The analysis result by the proposed method is compared with the experimental result.

Fast and precise position control of linear DC motor for carrier using seek control and neural network

This paper presents the position control method of the linear DC motor (LDM) for a parts carrier using seek control which considers variation of switching line according to variation of load mass. The proposed control method uses artificial neural network (ANN) algorithm considering the variation of switching line to each load. Switching line and moving velocity for each load mass are obtained by repetitive modification algorithm and are learned for a neurocontroller. The experimental results show that proposed method is very efficient in the position control of LDM for carrier.

A construction method of equivalent circuit and optimization of design variables in single-phase permanent-split capacitor induction motor

This paper presents the construction method of equivalent circuit and optimization of design variables in single-phase permanent-split capacitor induction motor. For the equivalent circuit, we propose the calculation method of magnetizing reactance according to slip from the circuit equation. Simulation results are compared with experimental results in the characteristics of 4 different models of the motors. The sequential quadratic programming (SQP) is applied to solve the optimal design.