This paper deals with efficient operation method for the electromechanical brake (EMB). A three-phase interior permanent magnet synchronous motor (IPMSM) is applied to the EMB operation. A current controller, speed controller, and position controller based on proportional-integral (PI) control are used to drive the IPMSM. Maximum torque per ampere (MTPA) control is applied to the current controller to perform efficient control. For MTPA control, the angle β is calculated from total input current, and the synchronous frame d–q axis current reference is determined by the angle β. The IPMSM is designed and analyzed with finite element analysis (FEA) software and current control is simulated by Matlab/Simulink using a motor model designed by FEA software. The simulation results were verified to compare with experimental results that are input current and clamping force of caliper. In addition, the experimental results showed that the energy consumption is reduced by MTPA.

This paper deals with clamping force simulation and experimental result of the Electro Mechanical Brake (EMB) for the High-Speed-Train (HST). Three phase Surface Permanent Magnet Synchronous Motor (SPMSM) is applied to the clamping force control of EMB. At the initial development stage, Proportional Integral (PI) current control under synchronous d-q axis frame was applied to the SPMSM torque control. In addition, an anti-windup controller, which is advantageous for fast current tracking, is proposed to improve the torque output. Matlab/Simulink simulation results were compared with the experimental results measured by the clamping force sensors of the EMB test rig. The experimental results were verified compared to the brake design specification of the High-Speed Electric Multiple Unit-430 Experimental (HEMU-430X) train.

This paper proposes a fault detection and the improved fault-tolerant control for an open fault in the five-phase inverter driving system. The five-phase induction machine has a merit of fault-tolerant control due to its increased number of phases. This paper analyzes an open fault pattern of one switch and proposes an effective fault detection method based upon this analysis. The proposed fault detection method using the analyzed patterns is applied in the power inverter. In addition, when the open fault occurs in the one switch of the induction machine driving system, the proposed fault-tolerant control method is used to operate the induction machine using the remaining healthy phases, after performing the fault detection method. Simulation and experiment results are provided to validate the proposed technique.

Recently, with the emergence of electro-mechanical brake (EMB) devices, a control method for an electric motor to replace the existing pneumatic actuator has been studied. The clamping force estimation control method (ECM) from the rotor position of the motor is primarily used because sensor installation is difficult owing to the temperature increase of the friction surface of the brake disk. However, to accurately control the clamping force according to the change in the friction surface and hysteresis characteristics of the motor, it is necessary to consider the installation of a force sensor. This study deals with the installation of force sensors and the sensor compensation control method (SCCM) for the clamping force of an EMB for high-speed train applications. To evaluate the proposed method, that is, the SCCM of the EMB, static control with the wheel in the non-rotating state and dynamic control with the wheel in the rotating state were performed. In addition, static control performance evaluation was performed under the maximum clamping force reference and continuous step reference input. Comparing the two control methods, the error rate of the SCCM was improved by up to 5 %. The results of evaluating the dynamic braking performance with the wheels rotating at 300 km/h showed that the SCCM had an improved deceleration pattern, and the braking speed was more than 3 s faster than that of the pneumatic braking system and ECM of the EMB.

This study deals with pre-shutdown test system in AC withstand voltage test for XLPE power cable, which is able to minimize electrical damage enough to investigate source of defects with naked eye when electrical breakdown is happened. Principle of this system is based on high speed shutdown of the test voltage just before the electrical breakdown by PBD system combined with time domain reflection (TDR) method of partial discharge. By experiments with model cables having artificial defects, its working abilities, such as shutdown speed and accuracy as well as operating condition were investigated. Through the test result of power cables with unknown defect, it was proven that this pre- shutdown AC voltage test system was successfully worked in the AC voltage test for power cable.

본 논문은 고속철도용 인보드 대차에 적용하기 위한 견인전동기 시스템의 설계 프레임워크를 다룬다. 최근 유럽에서는 새로 제작되는 철도차량에 인보드 대차 시스템을 적용하는 사례가 늘어나고 있으나, 국내에서는 개발 및 적용 사례가 없다. 인보드 대차는 아웃보드 대차에 비해 차량 중량과 주행 저항을 줄일 수 있는 기술이다. 이러한 장점에도 불구하고, 차축에 설치되는 베어링이 차륜의 안쪽에 위치하기 때문에 대차의 내부 공간의 효율적 활용, 견인전동기와 감속기 간의 최적화 설계 및 개선된 인터페이스가 요구된다. 본 논문에서는 최고운영속도 400km/h를 위한 고속철도차량의 동적특성곡선 설계를 통한 견인전동기의 설계목표를 선정하고 동일 설계목표에 대한 기존 감속기(driving gear)를 통한 동력전달 구조와 직접구동모터의 두가지 설계를 제안하였다. 또한, 아웃보드 대차가 설치된 국내 차세대고속철도차량(HEMU-430X)의 유도전동기의 출력대비 40% 이상 출력 증가를 위해 매입형 영구자석 동기전동기 구조의 적용, 극수 증가 및 수냉식시스템 적용을 통한 설계 및 해석결과를 제시하였다. 설계된 견인전동기는 유한요소분석(FEA)을 통한 전기자계해석 상용 소프트웨어인 JMAG(Ver. 22.1, JSOL)을 활용한 해석결과로 설계 타당성을 보였다.