Dae-Kyong Kim

Electromagnetic Field and Thermal Linked Analysis of Interior Permanent-Magnet Synchronous Motor for Agricultural Electric Vehicle

This paper presents a 3D numerical analysis of the thermal transient behavior of the air-cooled interior permanent-magnet synchronous motor (IPMSM) for agricultural electric vehicle (AEV) using finite-element method (FEM). The air-cooled IPMSM is investigated the temperature variation for the insulation of winding coil and demagnetization of permanent-magnet during the rated operation. Therefore, the prediction of a motor temperature is necessary at the motor design stage. This paper shows a good agreement both the numerical calculation and experimental results. The proposed method, electromagnetic field and thermal linked analysis, is able to predict the temperature distribution of IPMSM with the rated 7.5 kW continuous power.

Study on Heating Performance Improvement of Practical Induction Heating Rice Cooker With Magnetic Flux Concentrator

This paper presents a finite-element analysis (FEA) that features a model for electromagnetic-thermal coupling 3D-FEA. To confirm magnetic flux density and thermal distribution, we carry out 3D-FEA on an induction heating (IH) rice cooker with a magnetic flux concentrator (MFC). The analysis is conducted with respect to the bar-type MFC. The current waveform and temperature transition of the actual model is measured, and FEA modeling is based on the shape and current waveform of the model. The IH jar temperatures derived by the initial FEA model and the actual model are compared. The models show good agreement in terms of temperature transition. To improve efficiency and fast heating, the application of the MFC in the modeling is considered. To confirm the effect of the MFC, the initial and proposed models are compared using 3D-FEA results.

Thermal Analysis of Interior Permanent-Magnet Synchronous Motor by Electromagnetic Field-Thermal Linked Analysis

This paper reports an investigation of pulse width modulation (PWM) techniques for twophase brushless DC (BLDC) motors fed by a two-phase eight-switch inverter in a fan application. The three-phase BLDC motor is widely applied in industry; however, a lower-cost two-phase BLDC motor and drive circuit has been greatly in demand in recent years. In this paper, we introduce a mathematical model of the two-phase BLDC motor with sinusoidal back electromotive forces (EMFs) based on traditional three-phase BLDC motors. To simplify the drive algorithm and speed up its application, we analyze the principle of block commutation for a two-phase BLDC motor drive in the 180-electricaldegree conduction mode, and we further propose five PWM schemes to improve the commutation performance of the two-phase BLDC drive. The effectiveness of the proposed PWM methods is verified through experiments.

Cogging Torque Reduction of Single-Phase Brushless DC Motor With a Tapered Air-Gap Using Optimizing Notch Size and Position

This paper reports a stator shape optimization design for reducing the cogging torque of single-phase brushless dc (BLDC) motors by adopting an asymmetric air-gap to make them self-starting. A time step 2-D finite-element analysis (FEA) was carried out to analyze the characteristics of the single-phase BLDC motor. The Kriging model combined with Latin hypercube sampling and a genetic algorithm were used to reduce the cogging torque and maintain the efficiency and torque. As an optimal design result, the cogging torque of the optimal model was reduced. Finally, the analysis and optimal design results were confirmed by FEA as well as by experimental results.

Cogging torque reduction of single-phase brushless DC motor with a tapered air-gap using optimizing notch size and position

This paper reports a stator shape optimization design for reducing the cogging torque of single-phase brushless DC motor adopting an asymmetric air-gap to make them self-starting. Time step 2D-finite element analysis (FEA) was carried out to analyze the characteristics of a single-phase brushless DC motor. To reduce the cogging torque and maintain the efficiency and torque, the Kriging model based on Latin hypercube sampling (LHS) and a genetic algorithm (GA) were used. As an optimal design result, the cogging torque on the optimal model was reduced. Finally, the analysis and optimal design results were confirmed by FEA and the experimental results.

The MPPT control of photovoltaic system using fuzzy-PI controller

This paper proposes the fuzzy - PI controller for maximum power point tracking (MPPT) control of photovoltaic system. The output characteristics of the solar cell are a nonlinear and affected by a temperature, the solar radiation and influence of a shadow. The MPPT control is a very important technique in order to increase an output and efficiency of the photovoltaic system. The conventional constant voltage (CV), perturbation and observation (PO) and incremental conductance (IC) are the method which finding maximum power point (MPP) by the continued self-excitation vibration, and uses the fixed step size. If the fixed step size is a large, the tracking speed of maximum power point is faster, but the tracking accuracy in the steady state is decreased. On the contrary, when the fixed step size is a small, the tracking accuracy is increased and the tracking speed is slower. Therefore, in order to solve these problems, this paper proposes Fuzzy-PI controller. The PI controller of Fuzzy-PI controller is compensated for cumulative error of fuzzy control and fuzzy control adjusts the input value of PI controller. The validity of the controller proposed in this paper proves through the results of the comparisons These instructions provide you with the basic guidelines for preparing the full paper for 2013 International Conference on Electrical Machines and Systems, which will be held in Busan, Korea, Oct. 26 - Oct. 29, 2013. Please carefully follow these instructions to ensure legibility.

Development of active module considering the shadow influence of photovoltaic system

This paper proposes the active module considering shadow influence of photovoltaic system. The PV system is consisted series-parallel connection of PV module. The voltage and current between PV modules become imbalance when shadow occurs to PV module. If shadow occurs to the series connection PV module, the output current is limited to current of shaded PV module. Also if shadow occurs to the parallel connection PV module, the output voltage is limited to voltage of shaded PV module. These problems are caused power loss. Therefore, this paper proposes the active module that is consisted fixed module and variable module. The active module can compensates the shadow influence by changing connection of a variable module when shadow is occurred to PV module. A validity of the active module proposed in this paper proves through comparing with performance of conventional PV module.

A rotor shape design of interior PM motor for reducing cogging torque in electric air-conditioning system of HEV

This paper proposes a new design of rotor shape of the interior permanent magnet (IPM) motor used for the electric air-conditioning system of hybrid electric vehicles (HEV). The distribution of the residual magnetic flux density at the air gap was modified by the rotor surface shape and V-type magnet angle. The finite-element method (FEM) was applied to deterimne the optimal shape design of the rotor surface shape and V-type magnet angle because the IPM motor has extreme saturation in the rotor core. The validity of the proposed rotor shape optimization was confirmed by the manufactured IPM rotor core and the performance of the cogging torque was measured.

Design of multi-pole permanent magnet synchronous generator for small hydropower generation

This paper presents the design process of a 10kw gearless module type multi-pole permanent magnet generator that can be used in small hydro power generation. The specifications of the generator were selected to fit the capacity of a small river considering the permanent magnet type synchronous generator and characteristic analysis was carried out in 2 magnet formation for the production and price of a magnet with an initial curved magnet transformed to a straight magnet. The initial design for determining the approximate size of the generator using the loading distribution method (LDM) was determined and the detailed design was carried out using finite element analysis (FEA).

Study on reducing cogging torque of Interior PM Motor for electric vehicle

This paper proposes a new design of rotor shape of Interior Permanent Magnet Synchronous Motor (IPMSM) used for agricultural electric vehicle (AEV). The distribution of the residual magnetic flux density at the air gap is modified by rotor surface shape and V-type magnet angle. As a result, cogging torque and physical characteristic have been improved, and back electromotive force (back-EMF) of the suggested model has been improved to be closest to sine wave form compared to initial model. The validity of the proposed rotor shape optimization is confirmed by the manufactured IPM rotor core and measured the performance of the cogging torque.