• Journal of Advanced Marine Engineering and Technology
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• 제17권5호
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• pp.86-98
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• 1993

The application of A.C. motor for servo system is rapidly increased according to the recent advance of power electronics and digital control techniques. The induction motor which has a simple structure and needs less maintenance has become to be used widely in the industrial field for the speed and position control recently. In this paper, the full-bridge resonant inverter is applied to the speed control of single phase inducting motor. The digital PID control algorithm is used and the control parameter is determined by the Zigler-Nichols transient response method. The speed control is carried out by the one chip micro-processor(intel EV 8097BH) and control program is developed by the assembly language. By the experimental result, it is confirmed that the speed of single phase induction motor driven by full bridge series inverter can be smoothly controlled by a digital PID controller.

• 전기학회논문지P
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• 제55권4호
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• pp.161-166
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• 2006

In this paper, an automatic lighting control system is developed using microprocessor. The developed system consists of a digital lighting control unit, an analog lighting control unit, and a lighting control simulator. In the developed system, ATMega128 is used as the main controller. The developed digital lighting control unit consists of eight modules and the developed analog lighting control unit consists of six modules respectively. Additional, the developed simulator consists of a digital and an analog lighting control simulation using graphic user interface. And so this developed system can be applied to the controller design of the interior and exterior lighting equipment.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권6호
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• pp.395-402
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• 2000

This paper presents the improvement for speed characteristics of a Brushless DC Motor (BLDCM), it was applied to digital PI control for this. The practical PID control has been widely used to velocity control of DC motors. In this paper, a digital PI controller is used in order to decrease the speed error in constant velocity control of BLDCM. A TMS320C31 DSP is used for the microprocessor of digital PI control. The method using the DSP carry out the real-time control. The DSP has the rapid calculation ability and sampling time used lms. Driving BLDCM used 50W, motor input DC 150V and rotation speed 3000rpm. When BLDCM is to approval for discretion velocity at the acceleration and deceleration driving with any load, it was a feasible for stabilization control. Therefore, the experimental results indicate the superiority and validity of the velocity control by digital PI control.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.163-167
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• 2000

This paper presents the digital control of single-phase power factor correction(PFC) converter which has the variable gain according to the condition of inner control loop error. Generally the gain of inner current control loop in single-stage PFC converter has a constant magnitude. This has a bad influence on the power factor because current loop doesn't operate smoothly in the condition that input voltage is low In particular a digital controller has more time delay than an analog controller and degrades This drops the phase margin of the total digital PFC system,. It causes the problem that the gain of current control loop isn't increased enough. In addition the oscillation happens in the peak value of the input voltage open loop PFC system gain changes according to ac input voltage. These aspects make the design of the digital PFC controller difficult The digital PFC controller presented in this paper has a variable gain of current control loop according to input voltage. The 1kW converter was used to verify the efficiency of the digital PFC controller.

• 디지털융복합연구
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• 제18권9호
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• pp.9-15
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• 2020

본 연구는 디지털 격차가 노인의 디지털 일상생활에 미치는 영향력을 분석하는 것이다. 60세이상의 노년층을 대상으로 디지털 격차에 대한 적응경향성을 측정하여 집단으로 구분하였고, 디지털 의사소통 기술, 디지털 자신감, 디지털 자기통제감, 디지털 생활만족을 측정하였다. 연구모형은 교차설계 모형과 이중매개모형을 적용하였다. 연구결과, 첫째, 디지털 격차에 대한 적응 접근성이 높은 집단이 전반적인 디지털 일상생활에 긍정적인 영향을 미치는 것으로 나타났다. 둘째, 디지털 격차에 대한 적응 활동성이 높은 집단이 디지털 자기통제감에 긍정적인 영향을 미치는 것으로 나타났다. 셋째, 디지털 의사소통 기술이 디지털 생활만족에 긍정적인 영향을 미치며, 디지털 자신감과 디지털 자기통제감은 매개역할을 하는 것으로 나타났다. 이러한 연구결과를 토대로 노년층의 디지털 격차에 대한 극복 전략에 대해 논의하였다.

• Journal of Power Electronics
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• 제12권1호
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• pp.88-97
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• 2012

This paper presents a method for the digital control of a high power factor AC/DC converter employing the power balance control technique to achieve a fast response of the output voltage control. To avoid the effects of an output voltage ripple in the voltage control loop, the average output voltage is sampled and used as a feedback signal for the output voltage controller. The proposed control technique was verified by simulations using MATLAB/Simulink and its implementation was realized by a dsPIC30F4011 digital signal processor to control a CUK topology AC/DC converter with a 48V output voltage and a 250 W output power. The experimental results agree with the simulation results. The proposed control technique achieves a fast transient response with a lower line current distortion than is achieved when using a conventional proportional-integral controller and the power balance control technique with the conventional sampling method.

• 전기의세계
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• 제30권8호
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• pp.509-516
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• 1981

The optimal control theory is applied to the design of a digital control system for a nuclear reactor. A linear dynamic model obtained at 85% of rated power and a quadratic performance index are used. A minimal order observer used in cascade with the feedback controller is suggested as a state estimator. The total reactor power control is studied in the range of 80% to 100% of rated power, with the steady state and load-following control. The control algorithm considered is suitable for implementation in direct digital control.

• 디지털산업정보학회논문지
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• 제6권1호
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• pp.13-22
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• 2010

In this paper, we propose a management system for positioning and indicating the surveyed control point using RFID and UMPC. This system is composed of digital control point, management system and application. The digital control point transmits information of the surveyed control point and the management system receives the data from the digital control points and manages the scattered digital control points. The system offers three services for managing the surveyed control point. The first service is control point monitoring service for identifying the change of location, locating the missing control point and the second service is control point search service notifying selected control point to user, and the third service is control point land management service for editing the control point information in the land. Therefore, this system makes it easy for administrators to access the control point information of the scattered surveyed control point through the country and enhances the managing efficiency.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.36-40
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• 2003

On analyzing the power circuit of a DVR system, control limitations and control targets are presented for the voltage compensation in DVRs. The control delay in digital controllers increases the dimension of the system transfer function one degree higher which makes the control system more complicate and more unstable. Based on the power stage analysis, a novel controller for the compensation voltages in DVRs is proposed by a feedforward control scheme. Proposed controller works well with the time delay in the digital control system. This paper also proposes a guide line to design the control gain, appropriate output filter parameters and inverter switching frequency for DVRs in digital controllers. Proposed theory is verified by an experimental DVR system with a typical digital controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.288-293
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• 1987

This study presents the methodology for the hierachical construction of digital control system which can be of practical value to a wide application of sequence control. Optimization of digital control system, programming of the system by micropascal, and simulation of a model program under test are discussed.