• Title/Summary/Keyword: Power Signal

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A study on DSP based power analyzing and control system by analysis of 3-dimensional space current co-ordinates (3차원 전류좌표계 해석법에 의한 DSP 전력분석 제어장치에 관한 연구)

  • 임영철;정영국;나석환;최찬학;장영학;양승학
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.4
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    • pp.543-552
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    • 1996
  • The goal of this paper is to developed a DSP based power analyzing and control system by 3-Dimensional (3-D) space current co-ordinates. A developed system is made up of 486-PC and DSP (Digital Signal Processor) board, Active Power Filter, Non-linear thyristor load, and Power analyzing and control program for Windows. Power is analyzed using signal processing techniques based on the correlation between voltage and current waveforms. Since power analysis algorithm is performed by DSP, power analysis is achieved in real-time even under highly dynamic nonlinear loading conditions. Combining control algorithm with power analysis algorithm is performed by DSP, power analysis is achieved in real-time even under highly dynamic nonlinear loading conditions. Combining control algorithm with power analysis algorithm, flexibility of the proposed system which has both power analysis mode and control mode, is greatly enhanced. Non-active power generated while speed of induction motor is controlled by modulating firing angle of thyristor converter, is compensated by Active Power Filter for verifying a developed system. Power analysis results, before/after compensation, are numerically obtained and evaluated. From these results, various graphic screens for time/frequency/3-D current co-ordinate system are displayed on PC. By real-time analysis of power using a developed system, power quality is evaluated, and compared with that of conventional current co-ordinate system. (author). refs., figs. tabs.

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Design of a Bias Circuit for Reducing Memory Effects (Memory Effect를 줄이기 위한 바이어스 회로의 설계)

  • Kang, Sanggee
    • Journal of Satellite, Information and Communications
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    • v.12 no.4
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    • pp.115-119
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    • 2017
  • Intermodulation distortion degrades the S/N(signal-to-noise) of the original signal and also affects the adjacent channels. Intermodulation distortion is mainly caused by the nonlinear characteristics of the power amplifier. If the power amplifier with nonlinear characteristics has a memory effect, the intermodulation distortions occurred in the power amplifier are generated in various and complex forms. The predistorter is used as a way to improve intermodulation distortions. In order to efficiently utilize the performance of the predistorter, the memory effect of the power amplifier must be reduced. In this paper, we describe the design method of bias circuit to reduce the memory effect in power amplifiers. To reduce the memory effect, the bias circuit must have a high impedance for the signal and a low impedance for the envelope(modulating signal) and the second harmonic component of the signal. To verify the performance of the bias circuit designed considering the memory effect, a power amplifier operating at 170 ~ 220MHz was designed and implemented. The designed bias circuit has a large impedance in the operating frequency band and low impedance in the envelope signal and the second harmonic of the signal. As a result of the performance measurement, it was found that the asymmetric intermodulation distortion component is improved by 3.7dB.

Low Power Current mode Signal Processing for Maritime data Communication (해상 데이터 통신을 위한 저전력 전류모드 신호처리)

  • Kim, Seong-Kweon;Cho, Seung-Il;Cho, Ju-Phil;Yang, Chung-Mo;Cha, Jae-sang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.4
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    • pp.89-95
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    • 2008
  • In the maritime communication, Orthogonal Frequency Division Multiplexing (OFDM) communication terminal should be operated with low power consumption, because the communication should be accomplished in the circumstance of disaster. Therefore, Low power FFT processor is required to be designed with current mode signal processing technique than digital signal processing. Current- to-Voltage Converter (IVC) is a device that converts the output current signal of FFT processor into the voltage signal. In order to lessen the power consumption of OFDM terminal, IVC should be designed with low power design technique and IVC should have wide linear region for avoiding distortion of signal voltage. To design of one-chip of the FFT LSI and IVC, IVC should have a small chip size. In this paper, we proposed the new IVC with wide linear region. We confirmed that the proposed IVC operates linearly within 0.85V to 1.4V as a function of current-mode FFT output range of -100~100[uA]. Designed IVC will contribute to realization of low-power maritime data communication using OFDM system.

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Dimming Control Signal Transmisson of Electronic Ballast on the Power Line and Characteristics Measurement (전력선을 이용한 전자식 안정기 조광 신호 전송과 특성 측정)

  • 이상곤;정은택;강복연;양병렬;유홍균
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.4
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    • pp.691-700
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    • 1994
  • A power line in not so good in characteristics for communication, because it is a media to transfer the commercial electrical power, and its load noise and high frequency noise are so much. Thus, a simple method to transfer a remote control signal on the power line is studied. The already-existing method is that two signals with upper part eliminated is transmitted every N step. But the method is investigated which the transmitter sends a period signal eliminated in arbitrary phase. Thus the transmission power loss due to elimination of signal can be reduced to the minimum. To implement it, a timer calculating the time from zero-crossing point to the phase is required. The micro-controller, 87C51, precisely calculates the phase using one of two built-in timers. As a result, a remote control signal tramsmitter and receiver using a partially eliminated signal, which is better than the conventional technique using half-eliminated signal in a efficiency of power transmission, is realized, and its characteristics are analyzed.

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Compact Power-on Reset Circuit Using a Switched Capacitor

  • Seong, Kwang-Su
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.5
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    • pp.625-631
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    • 2014
  • We propose a compact power-on reset circuit consisting of a switched capacitor, a capacitor, and a Schmitt trigger inverter. A switched capacitor working with a clock signal charges the capacitor. Thus, the voltage across the capacitor is increased toward the supply voltage. The circuit provides a reset pulse until the voltage across the capacitor reaches the high threshold voltage of the Schmitt trigger inverter. The proposed circuit is simple, compact, has no static power consumption, and works for a wide range of power-on rising times. Furthermore, the clock signal is available while the reset pulse is activated. The proposed circuit works for up to 6 s of power-on rising time, and occupies a $60{\times}30{\mu}m^2$ active area.

Eigenvalue Analysis of Power Systems with GTO Controlled SSSC by the RCF Method (GTO 제어 SSSC가 설치된 계통의 RCF 해석법에 의한 고유치 해석)

  • Dong, Moo-Hwan;Kim, Deok-Young
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.230-231
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    • 2006
  • In this paper, the RCF(Resistive Companion Form) analysis method is used to analyze small signal stability of power systems including GTO controlled FACTS equipment such as SSSC. To apply the RCF analysis method in power system small signal stability problems, state transition equations of power system equipments and power systems with SSSC are presented. In eigenvalue analysis of power systems by the RCF analysis method, SSSC is modelled into the equivalents voltage source model and PWM switching circuit model. As a result of simulation, the RCF method is very powerful to calculate the oscillation modes exactly after the switching operations, and useful to analyze the small signal stability of power systems with periodic switching device such as SSSC.

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A Study on a Reactive Power Control using Digital Filtering (디지털 필터링을 이용한 무효전력 제어에 관한 연구)

  • 우천희;강신준;이덕규;우광방;이성환
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.4
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    • pp.517-524
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    • 1998
  • This paper discusses the development of a reactive power controller using digital signal processing. Digital Signal Processing is the technique of using digital devices to Process continuous signals or data, often in real-time. And DSP algorithms are associated with a discrete time interval between input samples. When one designs a digital filter, one can use a Laplace transform to determine the continuous time frequency response. The corresponding discrete time transform is called Z transform and depends upon discrete samples of the input spaced equally in time. The objectives of this paper are to minimize real power losses and improve the power factor of a given system. Also, the implementation of a direct-form non recursive filter on the TMS320C31 has been described. The application of this microprocessor-based controller using DSP on test system reveals its numerous advantages. Performance and features of the controller for the reactive power control are analyzed.

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A Study on the Control of Solenoid Valve for Heating by using Power Line Communication (PLC) (전력선 통신을 이용한 난방용 솔레노이드밸브 제어에 관한 연구)

  • 신관우;김용태;이윤섭
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.8
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    • pp.647-650
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    • 2003
  • PLC (Power Line Communication) is the communication method using the existing power line installed in houses and offices to convert and transmit high frequency communication signal from tens of KHz to tens of MHz, and receive the filtered signal using high frequency filter The advantage of PLC is that PLC uses the existing power line installed in houses and offices so it does not require separate power line. Easy and convenient access using electric outlets is another advantage of PLC. However, PLC has some disadvantages such as limited transmission power, high load interference and noise, variable signal attenuation, characteristic of impedance, and selective possibility of frequency property. We designed the boiler temperature control system unit by using the PLC modem. We can avoid unnecessary heating of separate temperature control unit, and save the cost accordingly control stability of the proposed system is proven through the experiment.

Transmission Signal Normalization Scheme for Advanced Terrestrial Digital Multimedia Broadcasting (AT-DMB 전송 신호 정규화 방안)

  • Lee, Sang-Woon;Kim, Young-Su;Yun, Jeong-Song
    • Journal of Broadcast Engineering
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    • v.15 no.6
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    • pp.868-875
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    • 2010
  • AT-DMB was developed to raise the transmission rate of existing T-DMB with backward compatability. The transmission and hierarchical video service technique were legislated as Korean TTA standards, and other application service techniques including data services are being developed for the commercial service. In this paper, we consider the power of transmission power level of signals in Advanced Terrestrial Digital Multimedia System according to the constellation ratio. And we propose a new scheme for normalization of transmission signal power level in AT-DMB system. Adopting this scheme, the signal power level of hierarchical modulated signal can be uniform in AT-DMB system both for B Mode and Q Mode.

Effect of Particle Contamination of Objective Lens in a CD-ROM Drive on Laser Diode Power and Photo Diode RE Signal (CD-ROM 드라이브의 대물렌즈 입자오염이 레이저 다이오드 파워와 포토 다이오드 RF 신호에 미치는 영향)

  • Pae, Yang-Il;Lee, Jae-Ho;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.1
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    • pp.66-71
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    • 2004
  • Airborne contaminant particles are intruded into optical disk drive(ODD) due to the flow caused by disk rotation and can be adhered to objective lens, which causes read/write errors. Such a phenomenon can be a serious problem for high-density storage devices. The purpose of this paper is to understand the effect of particle contamination of objective lens in a CD-ROM drive on laser diode power and photo diode RF signal. The measurements of laser power and readout RF signal were carried out by using a laser power meter and a time interval analyzer, respectively. The parameters for estimating a readout-signal' distortion were its jitter and amplitude. Alumina(Al$_2$O$_3$) particles were used as test dust particles. The results show that the failure for data access happened as the degree of lens contamination was greater than 20%.