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원충연,김연충,윤용호,김학성,이병국,천장성,Won, Chung-Yuen,Kim, Yuen-Chung,Yoon, Yong-Ho,Kim, Hack-Seong,Lee, Byuong-Kuk,Chun, Jang-Sung 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.1
본 논문에서는 고정자의 3고조파 전압 성분을 이용하여 브러시리스 직류 전동기의 회전자 위치를 간접 검출하는 방법을 제안하였다. 3고조파 전압 성분은 회전자의 위치 정보를 가지고 있고 이 전압을 이용하여 정류 신호를 만들어 낼 수 있다. 따라서 정류 신호를 이용한 브러시리스 직류 전동기를 센서리스로 운전하는 방식은 역기전력 파형과 상전류가 비교적 정확한 동기를 유지할 수 있으므로 넓은 속도 범위에서 안정적인 센서리스 운전이 가능하다. 또한 정밀 속도 제어를 위해 PLL 회로를 적용함으로써 저속도에서도 높은 분해능을 얻을 수 있다. 따라서 기존에 속도 제어를 위해 필요했던 고가의 속도 센서인 레졸버와 엔코더 역할을 대체하여 전체적인 구동 회로의 가격을 낮출 수 있다. This paper studies particularly applicable method for sensorless PM BLDC motor drive system. The waveform of the motor internal voltages(or back emf) contains a fundamental and higher order frequency harmonics. Therefore the third harmonic component is extracted from the stator phase voltage. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition. Also because of low resolution of estimated signal obtained by the proposed sensorless algorithm, to improve the wide range of speed response characteristic more exactly, we propose the rotor position signal synthesizer using PLL circuit based on estimated signals. Some experimental results are provided to demonstrate the validity of the proposed control method.
Evaluation of Optimum Decapitation Method in Vinyl Mulching Soybean Cultivation
Sang-Ouk Shin,Hyun-Tae Kim,Ha-Sik Shim,Young-Hoon Lee,Byuong-Won Lee,Chan-Sik Jeong,In-Yoel Baek,Keum-Yong Park 한국작물학회 2010 한국작물학회 학술발표대회 논문집 Vol.2010 No.04
overgrowth of soybean plants and thereby brings about lodging, decrease in pod number, damage by disease and insect pest, etc. This experiment was carried out to investigate optimum decapitation method in vinyl mulching soybean cultivation. Sinbuseoktae, local soybean variety was sown on May 25 and June 15 in 2009. Decapitation treatments(Non-decapitation, V8 stage-stem, V8 stage-apex, Flowering initiation stage, V8 stage-Stem+Flowering initiation Stage) were practiced on major growth stage on May25 seeding. Lodging did not occur in apex decapitation at V8 stage while other treatments had severe lodging. NAR from R5 to R7 stage was also highest in apex decapitation at V8 stage, which meaned optimum plant organ structure in utilizing light. On the other hand, flowering date and maturity date among treatments were similar. Seed yield in apex decapitation at V8 stage was highest with 274kg/10a, followed by flowering initiation stage with 249kg/10a. The apex decapitation at V8 stage had 26% yield increase as compared with the control of 216kg/10a due to heavy 100-seed weight.