Design and research of deep slot universal motor for electric power tools

Qi, Huang,Ling, Luo,Jichao, Cao,Wei, Xi The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6

In this paper, a deep slot universal motor is designed for electric power tools. The deep slot structure can reduce the cost of universal motor materials and improve production efficiency. A mathematical model of a universal motor is established and a simulation model is established by MagNet finite element software. Then, the static magnetic field distribution and load characteristics of the deep slot universal motor are analyzed. Different methods are adopted to improve the commutation spark of a deep slot universal motor. Finally, three 550-W and 9500-rpm prototype motors are tested. Simulation and experimental results indicate that an uneven air gap, brush offset by a certain angle, as well as different turns of the lead coil and the lag coil can effectively improve the commutation spark of a deep slot universal motor.

Reduced-order thermal behavior of universal motor-driven domestic food mixers/grinders using AC and DC supplies

Mercy, A.,Umamaheswari, B.,Latha, K. The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.9

This paper presents an improvement in the thermal performance of universal motor, which improves the efficiency and increases the life of the motor. Excessive heating in the winding can lead to an insulation failure of a universal motor and reduce the life of a food mixer. Hence, to avoid hot spots in machine parts and obtain a homogenous temperature distribution, it is necessary to take the thermal limits into consideration. To monitor temperature increase, a lumped parameter thermal model is designed with 12 nodes for a food mixer driven by a universal motor. This paper proposes a reduced-order thermal model for a universal motor used in food mixers to monitor its thermal behavior. In this paper, a 12th-order model is reduced to a 5th-order model using a balanced truncation reduction method. The reduced-order model is validated through simulation and experimental results by comparing its response with a full-order model. A thermal analysis is carried out using AC and DC supplies along with experimentation. It can be seen that when the universal motor is operated with a DC supply, its thermal performance is improved, which increases the life of the machine. This results in energy savings, since the efficiency of the universal motor is increased when it is operated using the DC supply.

Development of Micro/Nano Universal Testing Machine using a Piezoelectric Ceramic Actuator

권현규(Hyun Kyu Kweon),최성대(Seong Dae Choi) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.4

Micro/nano MUTM(Miniature Universal Testing Machines) are becoming increasingly popular for testing the mechanical properties of MEMS materials, metal thin films, and micro-molecule materials. And new miniature testing machines that can perform in-process measurement in SEM, TEM, and SPM are also needed. In this paper, new micro/nano MUTMs with a precision positioning system that can be used in SEM, TEM, and SPM have been proposed. Three type precision actuators are used in fine positioning system. One is the bimorph type PZT actuator, and the another is the multilayer type(inchworm) and the other is the nano motor. Coarse positioning is implemented by step motor. The size, load output, and displacement output of bimorph type MUTM are respectively 109×64×22(㎜), about 35g, and 0.4 ㎜. Multilayer type MUTM has the size of 60×46×27(㎜) and load output of 0.5 ㎏. And the displacement output is controlled with the block digital form. The results of the analysis and basic properties of the three types positioning system, and micro/nano MUTMs are presented in this paper. In addition, the experiment results of in-process measurement during tensile load in SEM and AFM are showed, too.

Optimal Product Design for Life Cycle Assessment (LCA) with the Case Study of Universal Motors

Ma, Jungmok,Kim, Namhun Korean Society for Precision Engineering 2016 International Journal of Precision Engineering and Vol.17 No.9

Though life cycle assessment can provide the analytic basis of environmental impact of products for engineering designers, it requires not only a significant amount of time but also a detailed bill of materials of the products to determine the optimal product designs. To overcome the barrier between life cycle assessment and design, in this paper, the optimal product design for life cycle assessment is studied. Instead of comparing a few design alternatives due to the barrier, design variables are allowed to vary as an optimization problem to minimize environmental impact. As a numerical example, the design of universal electric motors was demonstrated. Under the five different design cases, the optimal designs could be achieved to minimize the total environmental impact of universal motors.

신개념 하이브리드 동력장치 개발

김남욱(Kim, Nam-Wook),윤영민(Yoon, Young-Min),하승범(Ha, Seung-Bum),임원식(Lim, Won-Sik),박영일(Park, Young-Il),이장무(Lee, Jang-Moo) 한국신재생에너지학회 2005 신재생에너지 Vol.1 No.4

In this paper, a new drive system(SHS) for hybrid electric vehicle is proposed. As dual rotor hybrid electric vehicle using planetary gearsets, the SHS has the advantages of both series and parallel systems. The output speed and torque of SHS can be determined at specific point regardless of the engine's operating point. When the size of generator which is used in SHS is same as in THS, the SHS has more activities of engine control due to the ability that is operated in lower speed range. To maximize the performance of system, we carried out optimization for the three parameters that are engine, motorl and motor2. As the result of the optimization, we confirmed the SHS is more preferable to THS in fuel consumption and acceleration area.

신개념 하이브리드 동력장치 개발

김남욱(Kim, Nam-Wook),윤영민(Yoon, Young-Min),하승범(Ha, Seung-Bum),임원식(Lim, Won-Sik),박영일(Park, Young-Il),이장무(Lee, Jang-Moo) 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.11

In this paper, a new drive system(SHS) for hybrid electric vehicle is proposed. As dual rotor hybrid electric vehicle using planetary gearsets, the SHS has the advantages of both series and parallel systems. The output speed and torque of SHS can be determined at specific point regardless of the engine's operating point. When the size of generator which is used in SHS is same as in THS, the SHS has more activities of engine control due to the ability that is operated in lower speed range. To maximize the performance of system, we carried out optimization for the three parameters that are engine, motorl and motor2. As the result of the optimization, we confirmed the SHS is more preferable to THS in fuel consumption and acceleration area.

신개념 하이브리드 동력장치 개발

김남욱 ( Namwook Kim ),윤영민 ( Youngmin Yoon ),하승범 ( Seungbum Ha ),임원식 ( Wonsik Lim ),박영일 ( Youngil Park ),이장무 ( Jangmoo Lee ) 한국신재생에너지학회 2005 신재생에너지 Vol.1 No.4

In this paper, a new drive system(SHS) for hybrid electric vehicle is proposed. As dual rotor hybrid electric vehicle using planetary gearsets, the SHS has the advantages of both series and parallel systems. The output speed and torque of SHS can be determined at specific point regardless of the engine`s operating point. When the size of generator which is used in SHS is same as in THS, the SHS has more activities of engine control due to the ability that is operated in lower speed range. To maximize the performance of system, we carried out optimization for the three parameters that are engine, motor1 and motor2. As the result of the optimization, we confirmed the SHS is more preferable to THS in fuel consumption and acceleration area.

유니버셜모터 속도제어기의 고조파전류 특성에 관한 연구

임홍우,박수강,백형래 전력전자학회 2001 전력전자학회 논문지 Vol.6 No.2

A universal motor is a small dc series machine motor that is designed to operate from an ac machine. The characteristics of universal motors are high no-load and staring torque. Because of the high operating speed, the size of these motors for a given hp rating is typically smaller that other fractional hp ac machine, making it ideal for hand-held tools and appliances where weight, compactness, and speed are importance factors. A phase-angle control with AC drive system gains a high popularity due to their simple implementation, but contains the disadvantage of their poor input power factor, subharmonic current. Pulse width modulation control with DC drive systems increase the power factor as without delay phase angle. This paper analyzed the subharmonic characteristics of the phase angle control system that is controlled by zero voltage crossing similar to traditional method, and the dc chopper system that is used PWM. 유니버셜모터는 소형의 직류 직권전동기와 같은 기계적 구조를 가지며 교류.직류 전원을 양용할 수 있는 장점으로 동급의 일반전동기에 비해 높은 속도로 구동이 가능하므로 핸드드릴이나 진공청소기, 세탁기 등의 가정용 기기 등에 일반적으로 사용된다. 위상각제어기를 이용하여 모터로 입력되는 전압을 제어하는 방법은 간단한 구조 때문에 위상지연으로 인해 입력 역률 및 저차 고조파 전류특성이 좋지 않음에도 불구하고 널리 사용되고 있다. 브리지 정류기를 사용하여 교류 전원을 맥동하는 직류 전원으로 변환한 후 DC 초퍼로써 유니버셜모터에 입력되는 평균전압을 제어하는 방법은 제어기의 효율을 높일 수 있고 저차 고조파전류를 감소시킬 뿐만 아니라 저전력값에 대해서도 부하역률의 저하를 막을 수 있다. 본 논문에서는 기존의 제어기의 방법으로 저가의 위상각 제어기를 구서하고 EH한 저가의 마이크로 컨트롤러를 이용한 DC 초퍼시스템을 각각 구성하여 저차 고조파전류 특성을 비교 분석하였다.

복합가공기용 리니어 모터 시스템의 제어 연구

공경철(Kyoungchul Kong),전도영(Doyoung Jeon) 한국정밀공학회 2005 한국정밀공학회 학술발표대회 논문집 Vol.2005 No.10월

Though the technology on the ultra-precise machining has been developed intensively, the high speed and high precision for large machining range is still very hard to achieve. The linear motor system for the universal machining center is proper for high speed and high precision, but it has drawback of sensitivity to disturbance. In this research, two degrees of freedom controller based on the zero phase error tracking controller (ZPETC) and disturbance observer are proposed to improve the tracking performance and dynamic stiffness of linear motor system. The proposed controller is verified in simulations and experiments on a nano-positioner system, and the experimental result shows that the tracking performance improved. In addition, the PID optimization method is proposed for the commercialized controller such as the PMAC based system. The tracking as well as impedance is included in the cost function of optimization.

예비교사의 교직선택동기와 교사효능감관계에서 보편적 인성의 조절효과

김현경 한국유아교육ㆍ보육복지학회 2019 유아교육·보육복지연구 Vol.23 No.4

This study collected and analyzed data on 440 prospective teachers attending the department of infant education in the metropolitan area to verify the adjustment effect of universal personality in relation to the teacher’s motivation and teacher efficacy. The study found that, first, all of the major spokespersons showed significant static correlation. There were significant static correlations in the relationship between teacher motivation and teacher efficacy, teacher motivation and universal personality, teacher efficacy and universal personality variable. Second, the universal character of the pre-school teacher was shown to have partial control over the relationship between teacher choice motive and teacher efficacy. These results show that the universal character of the pre-school teacher has a partial adjustment effect in the relationship between the teacher choice motive and teacher efficacy, meaning that the teacher choice not only has a direct impact on the teacher efficacy, but also indirectly through universal character. The higher the level of the teacher-elector in the group with the higher universal character, the higher the teacher-effectiveness, while the higher the teacher-selector level in the group with the lower universal character, the more easily increased the teacher-effectiveness. Therefore, the implications of the analysis results were discussed, and the limitations of this study were suggested and further studies were proposed. 본 연구는 예비교사의 교직선택동기와 교사효능감 관계에서 보편적 인성의 조절 효과를 검증하고자 수도권 소재 유아교육과에 재학 중인 예비교사 440명을 대상으로 자료를 수집하고 분석하였다. 연구결과 첫째, 주요변인들은 모두 유의한 정적 상관을 보였다. 예비교사의 교직선택동기와 교사효능감, 교직선택동기와 보편적 인성, 교사효능감과 보편적 인성 변인 간의 관계에서 유의한 정적 상관가 있는 것으로 나타났다. 둘째, 예비교사의 보편적 인성은 교직선택동기와 교사효능감의 관계를 부분 조절효과를 보이는 것으로 나타났다. 이러한 결과는 예비교사의 보편적 인성은 교직선택동기와 교사효능감의 관계에서 부분 조절효과를 보이는 것으로 나타나 교직선택통기가 교사효능감에 직접적인 영향을 미칠 뿐만 아니라 보편적 인성을 통해 간접적으로도 영향을 미침을 의미한다. 보편적 인성이 높은 집단에서 예비교사의 교직선택동기 수준이 높을수록 교사효능감이 현격하게 높아지나, 보편적 인성이 낮은 집단에서는 교직선택동기 수준이 높더라도 교사효능감이 완만히 높아지는 양상으로 나타났다. 이에 분석결과의 시사점에 대해 논의하고 본 연구의 제한점과 추후 연구에 대한 제언하였다.