Doh-Young Park

Hybrid re-adhesion control method for traction system of high-speed railway

This paper describes a re-adhesion control system for the Korean High-Speed Railway. To reduce the wheel abrasion and to improve traction efficiency, the adhesion characteristics between wheel and rail are analyzed. Also the re-adhesion control system is designed as a subsystem of induction motor control. In order to verify the performance or the proposed system, a downscaled readhesion control simulator is utilized. Both simulation and running test are executed and the results are evaluated.

Design and implementation of HILS system for ABS ECU of commercial vehicles

The hardware in-the-loop simulation (HILS) system has historically been used in the development and testing of complex and costly systems such as military tactical missiles, aircraft flight control system, satellite control systems, and automotive systems. Especially in the automotive industry, HILS is an effective tool for design, performance evaluation and test of vehicle subsystems such as antilock brake system (ABS), active suspension system, and steering system. This paper describes a HILS model for an ABS/ASR application. Also the design and implementation of HILS system for development of the ABS ECU (electronic control unit) for commercial vehicles are presented. Fourteen degrees of freedom vehicle dynamics model is simulated in alpha-chip processor board. The proposed HILS system is tested by a basic ABS control algorithm. The HILS system simulation results show that the proposed HILS system maybe used to realistically test performance, stability, and reliability of the vehicle.

An modular-type axial-flux permanent magnet synchronous generator for gearless wind power systems

In this paper, the design and characteristics analysis of dual axial-flux permanent magnet synchronous generator, 60 |Hz|, 10 |kVA|, 300 |rpm| for wind energy system application are presented. The dual axial-flux generator has inherently desirable features such as; (1) by employing two air gaps, the rotor-stator attractive forces are balanced and no net axial or thrust load is applied on the generator bearings; (2) heat produced by the stator windings appears on the outside of the generator, and it is easy to remove the heat. This paper describes characteristics of a dual axial-flux type permanent-magnet generator for a gearless wind energy system, which aims to satisfy the variable operating conditions. Finite-element method (FEM) is applied to analyze generator performance at variable loads. The results of FE analysis show this generator has a promising future for wind turbine applications.

Analysis of insulation characteristics of low-voltage induction motor driven by IGBT PWM inverter

IGBT PWM inverter driven induction motors for variable speed applications have been widely used since their introduction. Recently, stator winding insulation failures have attracted much concern due to high dv/dt of IGBT inverter output. In this paper, the detailed insulation test results of 26 low-voltage induction motors are presented. Six different types of insulation techniques are applied to 26 motors. The insulation characteristics are analyzed with partial discharge, dissipation factor, and discharge inception voltage tests. Also, breakdown tests by high voltage pulses are performed.

Analysis of insulation characteristics of PWM inverter-fed induction motors

Inverter driven induction motors with high speed switching and advanced PWM techniques are widely used for variable speed applications. Recently, the insulation failures of stator windings have attracted much concern due to high dv/dt of IGBT PWM inverter output. In this paper, the detailed insulation test results of 25 low-voltage induction motors are presented. Five different types of insulation techniques are applied to 25 motors. The insulation characteristics are analyzed with partial discharge, discharge inception voltage, AC current, and dissipation factor tests. Also, breakdown tests by high voltage pulses are performed.

Re-adhesion control for high-speed electric railway with parallel motor control system

A parallel induction motor drive with PWM inverter control has been developed for high-speed railway applications. This paper describes a re-adhesion control system to improve tractive efficiency and to reduce wheel abrasion. The adhesion characteristics of the high-speed train are analyzed to obtain the maximum adhesion effort and the re-adhesion control system is designed as a subsystem of induction motor control. In order to verify the performance of the proposed system, a downscaled re-adhesion control simulator is set up and running tests are executed.

Analysis and Experimental Evaluation of Normal Force of Linear Induction Motor for Maglev Vehicle

This paper presents the analysis and experimental of the effective normal force and power consumption in a maglev vehicle. A maglev vehicle employs the electromagnets as suspension and linear motors for propulsion. These components give the higher ride comfort but suffered from energy efficiency. Therefore, a vector control-based algorithm and various air gaps are employed to increase the propulsion efficiency and lower the system energy consumption. The effective levitation load according to the levitation gap and normal force of a linear induction motor is calculated by power consumption in a levitation system and compared with finite-element analysis results. The experiment is carried out with the full-scaled train in test line and the efficiency of a propulsion system is also presented.

Passive Maglev Carrier Control with Consideration of Pitch Motion

This research aims to develop core technologies for passive carrier (no power in carrier itself) transfer system. The technologies are passive levitation, propulsion, and guidance, which can be great benefits for semiconductor and display manufacturing industries. Passive maglev carrier is necessary to precise position control for quiet and stable transfer operation. However, the structural characteristics of carrier and the installation errors of gap sensors cause the pitch motion. Hence, the controller design in consideration of pitch motion is required. This study deals with the reduction control of carrier pitch motion. PDA controller and PDA controller with pitch control are proposed to compare the pitch angle analysis. The pitch angle and the levitation precision are measured by experiment. Finally, the optimized design of pitch controller is presented and the effects are discussed. † Corresponding Author, einses@kimm.re.kr C 2016 The Korean Society of Mechanical Engineers 이영학 · 김창현 · 하창완 · 박도영 · 양석조 · 임재원 214

Novel on-line partial discharge monitoring system for generator/motor stator insulations

Nowadays on-line monitoring scheme with trending technique is widely adopted in insulation diagnosis. In this paper, two types of online monitoring instrumentation for an insulation diagnosis are proposed. The first unit obtains the parameters such as partial discharge magnitude and dynamic stagnation voltage (DSV) in selected frequency bands. The partial discharge activities can be interpreted more precisely by these techniques. The second one indicates the partial discharge spectra in reduced time resolution with lower cost. Several online sensors for partial discharges monitoring are also introduced.

Analysis of force characteristic of a linear induction motor considering secondary overhang effect

This paper presents the analysis of thrust characteristics of linear induction motor (LIM) using the three dimensional finite element method (3D FEM). In the LIM thrust characteristics, the transverse edge effect influences the thrust and conduction path of secondary reaction plate. Therefore, in this study, we examined the impacts of the edge effects with using 3D FEM analysis. The LIM of the full model was analyzed with 3D FEM and 2D FEM, and the thrust characteristics were compared. Five types of the secondary overhang model with and without cap were considered.