Reduction of Tooth Harmonic in Fractional-Slot Concentrated-Winding Permanent-Magnet Machines Using New Stator Design

Mengmeng Wu,Wenxiang Zhao,Jinghua Ji,Junqiang Zheng,Jianhua Luo 한국자기학회 2018 Journal of Magnetics Vol.23 No.2

Fractional-slot concentrated windings (FSCWs) are characterized with many advantages. However, their magnetic fields have rich space harmonics. These harmonics, especially tooth harmonics, have negative effect on machine performances. This paper proposes a new method to reduce the tooth harmonics in FSCW permanent-magnet (PM) machine, in which the magnetic distribution in air-gap will be affected by winding span radian. Also, a new stator structure is designed on the method. By using the new stator design, each order tooth harmonic can be reduced significantly and the working harmonic can also be increased slightly. Simultaneously, the unbalanced radial magnetic force can be significantly weakened. The basic principle of tooth harmonic reduction method can be analyzed by using the stator structure of the FSCW machine with single layer windings. Then, a three phase 18-slot/16-pole FSCW machine with double layer windings is newly designed, which can effectively weaken the tooth harmonic components of FSCW machines. It is shown that, under the fixed electrical and geometrical constrains, the designed FSCW machine has better performances, such as loss, vibration and noise, than the conventional ones.

상업용 설비 부하의 중성선 영상전류 저감장치 분석 및 적용에 관한 연구

김경철,이일무,백승현,Kim, Kyung-Chul,Lee, Il-Moo,Paik, Seung-Hyun 한국조명전기설비학회 2004 조명·전기설비학회논문지 Vol.18 No.5

현대 사회 전반에 걸쳐 개인용 컴퓨터와 같은 비선형 부하가 증가하여, 중성선에는 많은 고조파 전류가 흐른다. 3상 4선식 배전계통을 채용하는 중성선에 과다한 고조파 전류가 흐르면 여러 가지 고조파 장해를 일으킨다. 중성선 고조파 저감 대책으로 지그재그 변압기를 이용하는 영상 필터가 널리 쓰이고 있다. 본 논문에서는 상용화된 중성선 영상 전류 저감장치를 분석하고, 고조파를 저감시키기 위해서 상업용 설비 부하에 적용하고자 한다. 실측한 값과 MATLAB으로 시뮬레이션 한 값을 수치와 그래프로 비교해 보았다. With the proliferation of nonlinear loads such as commercial facilities in all of modern society high neutral harmonic currents have been observed. High neutral currents in three-phase four-wire distribution systems can cause lots of harmonic problems. The most common solution of neutral harmonic currents reduction is a zero phase sequence filter using zig-zag transformer. This paper analyzes a commercially available neutral line zero sequence currents reduction device and applies the equipment to commercial office loads for eliminating harmonics. Experimental results m compared numerically and graphically with simulation results through the use of MATLAB.

조명부하의 중성선 영상전류 저감장치 분석 및 적용에 관한 연구

김경철,이일무,정영호,백승현,Kim, Kyung-Chul,Lee, Il-Moo,Jung, Yung-Ho,Paik, Seung-Hyun 한국조명전기설비학회 2004 조명·전기설비학회논문지 Vol.18 No.3

With the proliferation of nonlinear loads such as lighting facilities in all modern society high neutral harmonic currents have been observed. High neutral currents in three- phase four-wire distribution systems can cause lots of harmonic problems. The most common solution of neutral harmonic currents reduction is a zero phase sequence filter using zig-zag transformer. This paper analyzes a commercially available neutral line zero sequence currents reduction device and applies the equipment to lighting loads for eliminating harmonics. Experimental results are compared numerically and graphically with simulation results through the use of MATLAB. 현대 사회 전반에 걸쳐 조명설비와 같은 비선형 부하가 증가하여, 중성선에는 많은 고조파 전류가 흐른다. 3상 4선식 배전계통을 채용하는 중성선에 과다한 고조파 전류가 흐르면 여러 가지 고조파 장해를 일으킨다. 중성선 고조파 저감 대책으로 지그재그 변압기를 이용하는 영상 필터가 널리 쓰이고 있다. 본 논문에서는 상용화된 중성선 영상 전류 저감장치를 분석하고, 고조파를 저감시키기 위해서 조명 부하에 적용하고자 한다. 실측한 값과 MATLAB으로 시뮬레이션한 값을 수치와 그래프로 비교해 보았다.

고속철도 전철변전소 피크전력 저감을 위한 기술개발 연구

임성수(Sung-Soo Lim),편장식(Jang-Sik Pyun),권경민(Kyoung-Min Kwon) 한국철도학회 2015 한국철도학회 학술발표대회논문집 Vol.2015 No.10

고속열차는 대용량 부하로서 열차 운행을 위한 필요한 전력을 각 구간에 설치된 고속철도 전철변전소에서 공급받고 있으나 운영환경 변화에 따라 고속철도 변전소의 피크전력이 점진적으로 증가하고 있는 추세이다. 피크전력의 증가는 변전소의 설비비용 증가 및 전력사용요금을 증가시키는 요인이 되고 있다. 또한 고속철도 등 전기철도에서는 견인전동기 구동으로 인해 부하의 변동이 심하고 고조파가 발생하여 통신유도장애, 과전류, 계전기, 변압기 오동작 및 소손 등과 같은 악영향을 미치게 된다. 이에 본 연구에서는 고조파 및 피크전력 관리를 목적으로 개발되고 있는 피크전력 저감장치와 능동형 고조파 필터에 대해 소개하고자 한다. These high-speed railways is increased the peak power due to load fluctuation occurrence in accordance with the operating status of the train, and it causes the energy costs increase. In addition, harmonic generated from the traction motor of high-speed railways, and it will have adverse effects such as communication induction failure of power equipment, over-current and malfunction. In this study, we introduce a research development results of active harmonic filter and peak power reduction device that has been developed for harmonic management and peak power reduction.

Size and Harmonic Reduced Wilkinson Baiun Using Parallel Coupled Line with Open Stub

Won-Kyun Lee,Hee-Yong Hwang 한국전자파학회JEES 2014 Journal of Electromagnetic Engineering and Science Vol.14 No.4

In this paper, a size-reduced Wilkinson balun with wide harmonic-suppressed band is presented. An accurate analysis of the parallel coupled line with an open stub (PCL-OS) is carried out. The PCL-OS structure shows excellent low pass filter and harmonic- suppression characteristics, which is useful for designing a low pass filter unit cell (LUC) with a reduced size. The designed Wilkinson balun at a 2.45 GHz center frequency not only shows an excellent harmonic suppression including the 5th harmonics up to 14 GHz over 15 dB, but it also has an area reduced to 48% of the conventional one.

헤어핀 형태의 결합 선로를 이용한 소형화된 링 하이브리드의 설계

이홍섭,황희용,Lee, Hong-Seop,Hwang, Hee-Yong 한국전자파학회 2007 한국전자파학회논문지 Vol.18 No.5

본 논문에서는 두 마이크로스트립 라인으로 이루어진 헤어핀 형태의 결합 선로를 이용하여 특성이 개선된 링 하이브리드를 설계하였다. 제안한 구조는 링 하이브리드의 $\lambda/4$ 라인에 헤어핀 형태의 결합 선로를 삽입하여 두 선로가 가까워짐에 따라 선로간의 커플링으로 세 개의 감쇠극이 생겨 넓은 저지대역을 갖는 결합 선로 구조를 이용하여 구성함으로써 링 하이브리드의 크기 감소뿐만 아니라 고조파 제거 특성도 부가하였다. 중심 주파수 2.55 GHz에서 일반적인 링 하이브리드와 특성이 같고 3차 고조파를 포함한 12 GHz까지 -20 dB 이하의 고조파 저지 특성을 가지고 있다. 또한 링 부분의 크기는 기존 링 하이브리드의 1/4 크기로 줄어들었다. 제작된 링 하이브리드의 측정된 주파수 특성 결과는 시뮬레이션 결과와 잘 일치한다. In this paper, the coupled microstrip lines of hairpin type are applied to design a compact microstrip ring hybrid. When the gap decreases, three attenuation poles are created by coupling between the lines. The proposed structure can achieve a significant reduction of size and suppression of the harmonics. And it has the same frequency responses of conventional ring hybrid at 2.55 GHz. The harmonics are suppressed to below -20 dB up to 12 GHz, including the third harmonic. The ring part size of the proposed ring hybrid is reduced to one forth of the conventional ring hybrid. The measured frequency responses agree well with simulated ones.

동적전압보상시스템에서 LC필터 전압궤환의 제어특성 비교

한운동 한국교통대학교 2015 한국교통대학교 논문집 Vol.50 No.-

Dynamic voltage restorers(DVRs) are mainly used to protect sensitive loads from the electrical network voltage disturbances such as sags or swells and could be used to reduce harmonic distortion of ac voltages. The typical DVR topology essentially contains a voltage source inverter (VSI) with LC Filter, an injection transformer connected between the ac voltage line and the sensitive load, and a DC energy storage device. For injecting series voltage, the PWM inverter is used and the low pass filter consist of inductor(L) and capacitor(C) eliminates the harmonics of the PWM voltage of the inverter. However there are voltage pulsation responses by the characteristic of the LC lowpass filter that eliminate the harmonics of the PWM output waveform of the inverter. Therefore, this paper compared control and frequency response characteristic of LC filter voltage feedback with the DVRs. The voltage control by LC filter should be connected in the line side since this feedback method allows a relatively faster dynamic response, enabling the elimination of voltage notches or spikes in the beginning and in the end of sags and strong load voltage THD reduction.

DVR시스템에 사용되는 인버터부의 LC필터 설계와 피드백 성능분석

박종찬(Jong-Chan Park),손진근(Jin-Geun Shon) 대한전기학회 2015 전기학회논문지 P Vol.64 No.2

Voltage sags are considered the dominant disturbances affecting power quality. Dynamic voltage restorers(DVRs) are mainly used to protect sensitive loads from the electrical network voltage disturbances such as sags or swells and could be used to reduce harmonic distortion of ac voltages. The typical DVR topology essentially contains a PWM inverter with LC Filter, an injection transformer connected between the ac voltage line and the sensitive load, and a DC energy storage device. For injecting series voltage, the PWM inverter is used and the passive filter consist of inductor(L) and capacitor(C) for harmonics elimination of the inverter. However there are voltage pulsation responses by the characteristic of the LC passive filter that eliminate the harmonics of the PWM output waveform of the inverter. Therefore, this paper presented design and feedback performance of LC filter used in the DVRs. The voltage control by LC filter should be connected in the line side since this feedback method allows a relatively faster dynamic response, enabling the elimination of voltage notches or spikes in the beginning and in the end of sags and strong load voltage THD reduction. Illustrative examples are also included.

LUC 구조를 이용한 윌킨슨 전력분배기 설계

이원균,황희용 강원대학교 정보통신연구소 2008 정보통신논문지 Vol.12 No.-

In this paper, the exact analysis of the LUC(Lowpass filter Unit Cell) and application to Wilkinson power divider are presented. The Z-parameter of LUC is derived. The structure of LUC shows wide stop band and sharp skirt characteristics. Using the characteristics we designed a miniaturized Wilkinson power divider with wide harmonic-suppressed band. The size of the proposed Wilkinson power divider is 10% smaller then the conventional Wilkinson power divider. The frequency response is the same with that of the conventional ones on near 2.45 GHz center frequency. Including the fifth harmonics, up to 13 GHz spurious responses are suppressed below to -18 dB.

개방 스터브를 갖는 평행 결합 선로의 해석과 브랜치 라인 하이브리드에의 응용

이원균(Won-Kyun Lee),황희용(Hee-Yong Hwang) 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.1

본 논문에서는 개방 스터브를 갖는 평행 결합 선로의 해석과 이를 이용하여 고조파 저지 특성을 갖는 소형화된 새로운 브랜치 라인 하이브리드를 제안한다. 먼저, 개방 스터브를 포함한 평행 결합 선로 전체의 Z-파라미터를 유도하였으며, 이는 넓은 저지 대역을 갖는 단위 저역 통과 여파기(LUC)의 특성을 갖는다. 이를 브랜치 라인 하이브리드의 설계에 적용하여, 중심 주파수 1.8 ㎓ 근처에서는 기존 브랜치 라인 하이브리드와 동일한 특성을 가지지만 크기는 약 1/2로 줄이고, 5체배 고조파를 포함한 12 ㎓까지 스퓨리어스 성분을 -20 ㏈ 이하로 저지하는 새로운 브랜치 라인 하이브리드를 설계하였다. In this paper, the exact analysis of the parallel coupled line with open stub and an application to branch-line hybrid are presented. The Z-parameter of the parallel coupled line with an open stub is derived. The structure shows the characteristics as a lowpass filter unit cell(LUC) with wide stop band. Using the characteristics we designed a miniaturized branch-line hybrid with wide harmonic-suppressed band. The size of the new branch-line hybrid is a half of the conventional branch-line hybrid. The frequency response is the same with that of the conventional one near 1.7 ㎓ center frequency. Including the fifth harmonics, up to 12 ㎓ spurious responses are suppressed below to -20 ㏈.