• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.580-583
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• 2002

An improved MPPT converter with current compensation method for small-scaled PV-applications is presented in this paper. The proposed method implements maximum power point tracking (MPPT) by variable reference current which is continuously changed during one sampling period. Therefore, the power transferred to the load is increased above $9\%$ by the proposed MPPT converter with current compensation method. As a result, the utilization efficiency of Photovoltaic (PV)-panel can be increased. In addition, as it doesn't use digital signal processor (DSP), this MPPT method has the merits of both a cost efficiency and a simple control circuit design. Therefore, it is considered that the proposed MPPT method is proper to low power, low cost PV-applications. The concept and control principles of the proposed MPPT method are explained in detail and its validity of the proposed method is verified through several simulated results.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.262-272
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• 2007

SAD (Sum of Absolute Difference) algorithm is the most frequently executing routine in motion estimation, which is the most demanding process in motion picture encoding. To enhance the performance of motion picture encoding on a VLIW processor, an optimal implementation of SAD algorithm on VLIW processor should be accomplished. In this paper, we propose an implementation of optimal scheduling of SAD algorithm with conditional branch on a VLIW-based high performance DSP. We first transform the nested loop with conditional branch of SAD algorithm into a single loop with conditional branch which has a large enough loop body to utilize fully the ILP capability of VLIW DSP and has a conditional branch to make the escape from loop to be achieved as soon as possible. And then we apply a modulo scheduling technique to the transformed single loop. We test the proposed implementation on TMS320C6713, and analyze the code size and performance with respect to processing time. Through experiments, it is shown that the SAD implementation proposed in this paper has small code size appropriate for embedded applications, and the H.263 encoder with the proposed SAD implementation performs better than other H.263 encoder with other SAD implementations.

• Journal of Aerospace System Engineering
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• v.1 no.4
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• pp.13-21
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• 2007

As one of YHF digital data link technologies, VDL Mode 2 is designed to be an air-to-ground subnetwork of the Aeronautical Telecommunication Network (ATN) based on the Open System Interconnection (OSI) architecture. VDL Mode 2 can be used in ATS Applications especially for CPDLC and ADS. And it is also expected to replace ACARS (Aircraft Communications Addressing and Reporting System) which has broadly been used in AOC for over 20 years. This paper presents the design result of VDL Mode 2 system under AOA (ACARS Over AVLC) environment for the implementation of bit-oriented ATS applications. The system is composed of airborne and ground subsystem. Airborne subsystem consists of VDR, CMU and an aircraft test equipment with CPDLC/ADS client applications for operational test and ground system consists of Ground Station which includes ground VDR and ground communication controller, simple DSP (Datalink Service Processor) and a ground test equipment with CPDLC/ADS server applications.

• Broadcasting and Media Magazine
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• v.1 no.1
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• pp.61-74
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• 1996

디지탈 오디오 방송(DAB)과 디지털 텔레비전(DTV), 고선명 텔레비전(HDTV) 방송의 실용화가 다가오면서 대용량의 디지털 오디오 신호를 주관적인 왜곡없이 압축, 복원할 수 있는 고음질 오디오 부호화 방식이 방송음향 기술전반에 응용되고 있다[1][2]. 또한 방송 채널에 있어서도 기존의 스테레오에서 다채널 오디오 시스템으로 진전하면서 가상 현실, 입체음향 등에 필수적인 음장재생 기술이 적용되고 있다[3][4]. 위와 같은 기술은 디지털 오디오 신호처리 기술의 발전이 가져온 결과로 미래의 방송기술을 변화시키고 있다. 본 고에서는 디지털 방송 시스템에 있어서 디지털 신호처리 기술의 응용 분야를 살펴보고 새로운 기술을 소개하기로 한다.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.645-650
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• 2000

this paper deals with HVDC Light(High Voltage Direct Current) system using space vector PWM(SVPWM) method. Because the system of this paper has d-q control scheme for HVDC Light system. HVDC Light system represented in this paper is capable of controlling active and reactive power independently. For this system. V-I curve and control methods are proposed. Also this paper describes the design of a digital system for applications in power converters such as those that would be used in the next generation of HVDC system. Finally HVDC system is implemented using DSP TMS320C31

• Journal of Power Electronics
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• v.3 no.1
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• pp.1-9
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• 2003

This paper presents a performance analysis of typical Auxiliary Resonant Commutation Snubber-assisted three phase voltage source soft switching inverter which can operate under a condition of Zero Voltage Switching (ZVS) using a digital control scheme which is suitable for high power applications compared with resonant DC link snubber assisted soft switching inverter. The system performances of this inverter are illustrated and evaluated on the basis of experimental results.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.441-443
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• 1994

Modern control theory and high speed switching device such as IGBT have been developed day by day, but it hardly has been applicated practically to the various fields of industry, specially power electronic fields, because there is no cost effective hardware that accommodates modern control theory. Thus, in our study, DSP based ultra high speed general controller which may be exclusively used for power electronic applications is developed.

• Journal of Communications and Networks
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• v.1 no.2
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• pp.86-88
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• 1999

The Discrete Fourier Transform (DFT) and the Inverse Discrete Fourier Transform (IDFT) are commonly used in signal processing applications, in particular in digital communication sys-tems using the multi-carrier modulation principle. In such systems an IDFT is computed at the transmitter end, and a DFT at the re-ceiver end. This paper examines a technique of computations, for which only negligible differences appear between the DFT and the IDFT calculations while the number of arithmetic operations re-quired is substantially reduced. This offers significant advantages for the design of an IDFT/DFT processor for Discrete Multitone(DMT) systems.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.1
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• pp.52-58
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• 2003

The application of a sliding mode control for improving the dynamic response of an induction motor based speed control system is presented in this paper and provides attractive features, such as fast response, good transient performance, and insensitivity to variations in plant parameters and external disturbance. However, chattering is a difficult problem for which the sliding mode control is a popular solution. This paper presents a new fuzzy-sliding mode controller for a sensorless vector-controlled induction motor servo system to practically eliminate the chattering problem for traction applications. A DSP based implementation of the speed control system is employed. Experimental results are presented using a propulsion system simulator. The performance of the drive is shown to be practically free from chattering.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.508-511
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• 1992

Modern control theory has been developed day by day, but it hardly has been applicated practically to the various fields of industry, specially power electronic field, because there is no cost effective hardware that accommodates modern control theory. Thus, in our study, DSP based ultra high speed general controller which may be exclusively used for power electronic applications is developed.