• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.472-481
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• 2006

In the conventional SRM with multi-rotor teeth, the air gap must be very small in order to drive the SRM in the saturation region that is necessary for high output torque. However, this leads to the problem of overheating; particularly in the case of a small-size SRM This paper discusses the design of a new type of SRM, namely the rolled rotor SRM. This new type does not require more than a single region of a very small airgap. This solves the overheating problem in the small size SRM. Moreover, the use of the rolled rotor, instead of the conventional toothed rotor, grades the airgap region in a fashion that gives a smooth variation in the reluctance and smooth shapes of both current and torque. The latter functional behavior is required in many applications such as servo applications. The paper first addresses general design steps of the rolled rotor SRM then proceeds to the simulation results of the new SRM in order to evaluate the advantages gained from the new design. In addition, this paper compares the torque ripples obtained from the new design to its equivalent conventional one.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.25-31
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• 2007

This paper presents a comparison of different current controller response characteristics of SRM. The most common current controllers of the SRM is hysteresis type. The hysteresis controller is easy to implement and fast current control response, but has the inherent disadvantage of switching frequency variations. The other common type of current controller is PI scheme. The design of a classical PI current controller with fixed parameters for SRM is not an easy task due to the extreme nonlinear characteristics. In this paper, some linearization technique is used for design of PI current controller. Experimental results of 1-hp SRM are presented for the basic reference data which can be used to select the proper current control scheme according to the applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.586-592
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• 2018

SRMs are difficult to design using a simple mathematical model and, consequently, numerical analysis based characteristics analysis is used including drive circuits. In this process, it is necessary to analyze the trends according to the change of the design factors, however, many of the design factors affect each other. In order to shorten the design time and achieve a proper design, a modeling technique based on the design parameters is needed. For this purpose, this paper summarizes the formulas employed for shape modeling by minimizing the number of major design factors of the SRM, and proposes a methodology for SRM design using these formulas. In particular, we propose a design method for a 6/4-pole model, one which has been studied for a long time, and showed an example of a design produced by the proposed method.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.6
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• pp.534-542
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• 2003

Small electric motors in an automobile perform various tasks such as engine cooling, pumping, HVAC etc. At present, most of them are DC motors supplied by 12V or 24V batteries. However, DC motors suffer from low efficiency, life cycles and reliability. Therefore, there is a growing interest in substituting DC motors for advanced at motors including switched reluctance motors(SRM). Although there are several other forms SRM convertors, they are either unsatisfactory to the control performance or unsuitable for the 12V battery source. Especially, a conventional asymmetric converter of SRM provides the best flexible and effective control to the current waveform of SRM, but it has the most switches and produces conducting voltage drops across two power switches during SRM operation. For automotive applications with a 12V battery source, this circuit is inadequate. For considering the requirement for effective operation and simple structure of converter in the limited internal circumstance of automobiles, the author inclines toward selecting Modified C-dump converter and Energy efficient c-dump converter.

• Information Systems Review
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• v.14 no.2
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• pp.21-46
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• 2012

Organizations that make widely use of information technologies can be more efficient. But, the dependence of information technologies leads to an increase in threat of security. This is the reason why organizations are investing in security risk management (SRM) which is designed to protect of information assets. Noting a lack of empirical research in SRM, we investigate the key factors having a direct effect on performance of SRM. Particularly, this study focused on identifying factors influencing awareness of SRM and Intention to develop SRM in Organization. Based on relevant literature review, six motivating factors, including Behavior for Security Management, Compliance with Security Policy, perceived Benefits, Perceived Sacrifice, Social Pressure, Experience of Security Risks, were initially identified. The results indicated that most perception factors were positively related to Organization's intention to develop SRM and awareness of SRM, which then had positive impact on performance of SRM. But Perceived Sacrifice was not significantly related to two variables which is Organization's intention to develop SRM and awareness of SRM.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.912-914
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• 2002

Single phase SRM(Switched Reluctance Motor) can not be started by itself and torque ripple is more generated than multi-phase SRM. But it is excited by single phase current and has very simple structure. Therefore it can be used in domestic appliance. Torque and speed of single phase SRM is controlled by adjusting exciting current and exciting section. Driver, which is composed with absolute encoder and DSP, is fabricated for control of exciting section on this paper. Then driving characteristics with exciting section is confirmed by using salient pole rotor type single phase SRM, which is fabricated in preceding research.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.99-102
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• 2006

This paper proposes a DITC(Direct Instantaneous Torque Control of SRM (Switched Reluctance Motor) using a novel 4-level converter for smooth torque control and high efficiency. DITC of SRM is very useful for smooth torque control, but the driving efficiency is low due to advanced current that does not produce torque. For the high efficiency control of SRM, fast excitation and demagnetization of phase current are required. A novel 4-level converter and a new control scheme are present to improve the driving efficiency. The proposed DITC of SRM using 4-level converter is verified by computer simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1047-1054
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• 2007

This paper presents a high efficiency direct instantaneous torque control (DITC) of Switched Reluctance Motor(SRM) based on the nonlinear model. The DITC method can reduce the high inherent torque ripple of SRM drive system, but drive efficiency is somewhat low due to the high current and switching loss during commutations. In order to reduce a torque ripple, a fast torque reference trajectory is selected at every instantaneous rotor position. Based on the nonlinear model of SRM, the developing torque by one phase is fixed and the other phase is regulated for minimum switchings of phase switch and variation of torque. The switching during commutation can be reduced and fast commutation can be obtained in the proposed method. As a result, drive efficiency could be improved as well as torque ripple reduction. The validity of proposed method is verified by computer simulations and comparative experiments.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.705-708
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• 2000

Switched Reluctance motors(SRM) attract much attention in motor because they are reliable and inexpensive. With advance in power electronics and high-speed processors the performance of SRM has been enhanced greatly. But they require rotor position information to operate, In many systems rotor position sensors are undesirable and have disadvantages. To overcome the disadvantages include by position sensors a number of sensorless methods for SRM's have been proposed by researchers. This paper describes a method for indirect sensing of rotor position in SRM's pulsewidth modulation voltage control. The method required no priori knowledge of motor parameters excepts for the number of stator and rotor poles. The detection method uses the change of the derivative of the phase current to detect the position.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.533-534
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• 2011

본 논문은 고속블로워 시스템용 2상 4/2 SRM(Switched Reluctance Motor)과 3상 6/2 SRM의 토크 리플 최소화를 위한 가변 공극형 회전자 타입을 제안하고 그에 대한 특성 해석을 수행하였다. 연속적인 토크를 얻기 위하여 정 토크 구간을 확장할 수 있는 형상을 적용하고 고속에서의 리플을 최적화 할 수 있는 가벼 공극형 구조를 제안하였다. 기존에 제안되어진 2상 고속 4/2 SRM의 특성과 제안된 3상 고속 6/2 SRM의 특성을 FEM(Finite Elements Method) 해석을 통하여 비교해봄으로 고속에서의 개선된 토크 리플을 검증하였다.