http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
승강기 도어용 자속교번 영구자석 전동기의 토크 맥동 저감
황홍식(Hongsik Hwang),조정현(Jeonghyun Cho),이치우(Cheewoo Lee) 대한전기학회 2019 전기학회논문지 Vol.68 No.2
A flux-switching permanent magnet (FSPM) motor using ferrite magnet is proposed to replace a permanent magnet synchronous motor (PMSM) for elevator door applications. The prototype of an FSPM motor has been built up for experimental validation. Back-electromotive force (EMF) is estimated to prove that simulated results are correct and reliable. The efficiency of an FSPM motor has been verified to be comparable to that of a PMSM in spite of using ferrite magnet, but there is a disadvantage in torque ripple due to the interaction of harmonic components between back-EMF and magneto-motive force (MMF). However, most of researches on an FSPM motor have been focused on eliminating the harmonic components of back-EMF. In this paper, the design process of an FSPM motor based on winding function theory has been given to diminish torque ripple by considering the harmonic components of back-EMF and MMF along with cogging torque at the same time.
새로운 2상 8/6 SRM의 구조적 특성에 관한 비교 연구
이치우(Cheewoo Lee),황홍식(Hongsik Hwang),오석규(Seok-Gyu Oh) 대한전기학회 2017 전기학회논문지 Vol.66 No.2
This study presents a novel two-phase eight stator poles and six rotor poles (8/6) switched reluctance machine (SRM) that can compensate for the vibration and noise problems of two-phase 6/3 SRM and compare the characteristics of two SRMs. In the case of two-phase 6/3 SRM, the short flux path and the flux direction inside the stator are not reversed, so they have high efficiency characteristics. However, the use of three rotor poles causes problems of vibration and noise because the radial force applied to the rotor poles is not balance. The proposed two-phase 8/6 SRM has advantages of 6/3 SRM such as the fluxreversal-free stator and it can improve vibration and noise by using six rotor poles due to balanced radial force acting on the rotor poles. In order to make a reasonable comparison between two SRMs, the electromagnetic field structure of 8/6 SRM is designed to have equivalent torque characteristic to 6/3 SRM and then the copper loss and core loss are compared and analyzed. Finally, we compare the effieicney of two SRMs using finite element analysis and compare the distribution of radial force acting on the rotor poles based on Maxwell’s stress method
김병조(Byeongjo Kim),황홍식(Hongsik Hwang),이치우(Cheewoo Lee) 한국자기학회 2018 韓國磁氣學會誌 Vol.28 No.2
This paper investigates the design of a single-phase brushless DC (BLDC) motor by employing asymmetric air gap to meet the characteristics of vacuum cleaner applications such as low torque and high speed. Also, one of the key objectives has to be reasonable efficiency since it is a disadvantage in a single-phase BLDC motor. Asymmetric stator pole surface needs to be effectively customized to satisfy several important performances such as starting torque and continuous torque at high speeds. Starting torque is modified by using a mechanism of phase difference between cogging torque and back electromotive force. In this paper, two types of asymmetric air gap are designed by changing the ratio of maximum air gap to minimum air gap, and switching on and off angles are determined at the same time after comparing key performances in case of no load and rated operation conditions.