• Journal of the Korean Society of Manufacturing Process Engineers
• /
• 제12권4호
• /
• pp.16-21
• /
• 2013

This paper presents a DC link voltage control method to reduce the ripple current and the switching loss in the sinusoidal current drive system for the wide-speed range PMSM. The DC link voltage of the three phase inverter in the sinusoidal current drive system is designed by the back-EMF voltage at maximum speed of the PMSM. In general, the drive systems have used the constant DC link voltage without reference to the motor speed. The current ripple causes hysteresis loss and makes noise. In addition, the switching loss on the inverter increases in proportion to the rise in the DC link voltage. In this paper, we propose the variable DC link voltage control method to reduce the current ripple in the PMSM drive system. We show reduction effect of the current repple and the switching loss through simulation results.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.924-926
• /
• 2005

This paper presents an excellence start-up performance drive system of Switched Reluctance Motor(SRM) for hoist. At first, the SRM design method of Hoist drive is expounded, and suitable Digital control arithmetic of SRM Hoist drive is advanced in the paper. Finally, some correlative experimentation has been finished, and the SRM Hoist drive has been confirmed in the experimentation.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제1권4호
• /
• pp.477-482
• /
• 2012

This paper describes a new rotor position sensorless control method for SRM drives based on an improved simplified flux linkage method. In the traditional simplified flux linkage method, every phases take turns conduction and current chopping control method is used. Every phases take turns conduction means turning on the incoming working phase while turning off the working phase. This conduction mode causes coupling between turn-on and turn-off angles, which goes against optimal efficiency or torque ripple minimization with sensorless speed control. In the improved simplified flux linkage method, turn-off angle is calculated by flux loop, the turn-on angle can be given arbitrarily and has no relations with the turn-off angle, and the current chopping control method is used. The speed and rotor position can be estimated then. Finally, a sensorless SRM speed control system and an experiment platform with DSP are built and validity of this method is confirmed.

• Journal of Electrical Engineering and Technology
• /
• 제9권6호
• /
• pp.1944-1953
• /
• 2014

This paper shows the design and control methods of the bidirectional DC-DC converter to generate the proper DC-link voltage of a PMSM drive. Conventionally, because the controllable power of the PWM based voltage source inverter is limited by its DC-link voltage, the DC-DC converter is used for boosted DC-link voltage if the inverter source cannot generate enough operating voltage for the PMSM drive. In this paper, to obtain more utilization of this DC-DC converter, optimal DC-link voltage control for PMSM drive will be explained. First, the process and current path of the DC-DC converter will be illustrated, and a control method of this converter for variable DC-link voltage will then be explained. Finally, an improvement analysis of the optimal DC-link voltage control method, especially on the deadtime effect, will be explained. The DC-DC converter of the proposed control method is verified by the experiments by comparing with the conventional constant voltage control method.

• Proceedings of the KIPE Conference
• /
• 전력전자학회 2003년도 추계학술대회 논문집
• /
• pp.51-55
• /
• 2003

In this paper, the authors propose a new high performance Built-in Type spindle motor drive using vector-controlled technique at 15,000 r/min. Control method is changed by variation of motor speed in a conventional Built-in type spindle drive. In the drive system to be presented, the conventional vector control is used in the low-speed range, and the vector control without encoder is used in the high-speed range. Furthermore, in order to drive the motor from 0 to 15,000 rpm smoothly, the vector control with encoder in the low-speed range (from 0 to 8,000 rpm) is utilized and the vector control without encoder in the high-speed range (from 8,000 to 15,000 rpm) is utilized. This paper describes problem of control method in conventional spindle drive and proposes control method as variation of motor speed

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.439-440
• /
• 2006

This research proposes a novel method of shape display to present 3-dimensional objects. Shape displays allow us to feel the actual volume of the object, unlike conventional 2D visual displays of 3D objects. The proposed method employs a wire frame structure to present 3D objects. The wire frame is composed of small units driven by shape memory alloy(SMA) actuators. The drive unit is analogous to the agonist-antagonist system of animal musculoskeletal systems, where the SMA actuators serve as agonist and antagonist muscles. The force in the SMA actuator is controlled by electrical current. The drive unit is equipped with the locking mechanism so that it can sustain the external force exerted by the user as well as the own weight of the wire frame structure. By controlling the current into the SMA actuator and locking mechanism, we call control the angle of the drive unit. A chain of drive units enables presentation of 2 dimensional objects. 3 dimensional presentations are possible by collecting the chains of drive units.

• Journal of Information Science Theory and Practice
• /
• 제9권2호
• /
• pp.33-46
• /
• 2021

The purpose of this paper is to analyze the case of 'drive-thru' services newly introduced and tried in libraries in Korea under the influence of COVID-19, and to develop and propose a service model so that this service can be continuously applied to all libraries in the future. Therefore, the method of study was selected and analyzed by selecting one of the representative libraries that provide related services in Seoul Special City, Incheon Metropolitan City, and Anyang City of Gyeonggi Province. In addition, a focus group interview was conducted with twelve people in charge to find a way to apply the drive-thru service to the library. As a result, the library's drive-thru service is a way to fulfill the library's original purpose of providing information materials while minimizing faceto-face contact with users. It was concluded that it is a suitable method for a library of complex buildings, where there is a lack of parking space. In addition, it was deduced that it may be one of the ways to use the library efficiently for office workers who are unable to use library services during the opening hours. Therefore, if the drive-thru service is implemented according to the developed model, it is expected to increase the library visit rate and data utilization rate.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• 제29권4호
• /
• pp.108-115
• /
• 2015

This paper proposed a optimal current control method to improve efficiency of BLDC motors. The aim of the proposed method is to use the maximum torque operating method by increasing the effective voltage at the maximum torque point unlike existing SPM operating method. The proposed method is based on existing IPM maximum torque operating method grafting onto a square wave operating of SPM motors. As the method of increasing the effective output voltage from inverter using the maximum torque point, the proposed method is to improve efficiency of BLDC motors using the same amount of the existing current effectively. For this method, the maximum torque point is carried out by FEA and analysis of magnetic flux vector. In this paper, the prototype of general-purpose BLDC drive is manufactured and the performance characteristic and validity are verified.

• Journal of Power Electronics
• /
• 제6권4호
• /
• pp.340-346
• /
• 2006

A high efficiency drive technique for synchronous reluctance motors (SynRM) using a neural network (NN) is presented in this paper. High efficiency drive condition depends on the mathematical model of SynRM. A NN is employed as an adaptive model of SynRM. The proposed high efficiency drive technique does not require an accurate mathematical model of SynRM. Moreover, the proposed method shows robustness against machine parameter variations because the training algorithm of the NN is executed on-line. The usefulness of the proposed method is confirmed through experimentation.

• Proceedings of the KIPE Conference
• /
• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
• /
• pp.235-238
• /
• 2004

The simple motor construction and low cost, fault tolerant power electronic drive has made the switched reluctance drive a strong contender for many applications. But the switched reluctance drive does exhibit higher levels of vibration and acoustic noise than that of most competing drives. The main source of vibration in the switched reluctance drive is generated by rapid change of radial force when phase current is extinguished during commutation action. In this paper, a hybrid excitation method is proposed to reduce vibration and acoustic noise of the switched reluctance drive. The hybrid excitation has 2-phase excitation by long dwell angle as well as conventional 1-phase excitation. The vibration and acoustic noise are reduced because the scheme reduces abrupt change of excitation level by distributed and balanced excitation.