• Title/Summary/Keyword: Harmonics and reactive power

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A Study on the Monitoring System of Passive Filter to Improve Power Quality (전력품질 개선을 위한 수동필터 모니터 시스템에 관한 연구)

  • Yu, Jae-Geun;Lee, Sang-Ik;Choe, Gyu-Ha
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.89-91
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    • 2007
  • In this paper, we developed DSP based control system to automatically open and close passive filter, which is used to reduce harmonics, according to operating condition of loads. Passive filter control system automatically open and close each branch of filter according to working conditions of loads by sending signals to open and close installation of passive filter after measuring and monitoring voltage, current, harmonics, reactive power, power factor and so on. We verified it's performance by connecting control system with passive filter in the power line using the 100[HP] d.c. motor drive, opening and closing passive filter according to operation condition of motor, and measuring harmonics and reactive power, etc.

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A Study on the Control System of Passive Filter to Reduce Harmonics (고조파 저감을 위한 수동필터의 제어시스템에 관한 연구)

  • 전정채;유재근;이상익
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.4
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    • pp.124-130
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    • 2004
  • In this paper, we developed DSP(Digital Signal Processor)-based control system to automatically open and close passive filter, which is used to reduce harmonics, according to operating condition of loads. Passive filter control system automatically open and close each branch of filter according to working conditions of loads by sending signals to open and close installation of passive filter after measuring and monitoring voltage, current, harmonics, reactive power, power factor and so on. We verified it's performance by connecting control system with passive filter in the power line using the 100HP D.C motor drive, opening and closing passive filter according to operation condition of motor, and measuring harmonics and reactive power, etc.

A Series Active Power Filter For Harmonic Currents And Reactive Power Compensation (고조파 전류와 무효전력보상을 위한 직렬형 능동전력필터)

  • 김진선;고수현;김영석
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.5
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    • pp.221-229
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    • 2003
  • This paper suggests a control algorithm of 3-phase 3-wire series active power filter. This suggested algorithm can compensate source harmonics and reactive power in 3-phase 3-wire power distribution systems. These harmonics are generated by nonlinear loads such as diode rectifiers and thyristor converters. This control algorithm extracts a compensation voltage reference from performance function without phase transformation. Therefore, this control algorithm is simpler than any other conventional control algorithms. 3-phase 3-wire series active power filters which have a harmonic voltage source and a harmonic current source are manufactured and experiments are carried out to verify the effectiveness of suggested control algorithm.

A Study on the Reduction of harmonics by Current type PWM - Inverter (전류형 PWM 인버터에 의한 고조파 저감에 관한 연구)

  • Lee, Kye-Ho;Jang, Young-Hak;Yang, Seung-Hak;Jung, Young-Gook
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.359-361
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    • 1987
  • It is known that the reactive component of AC power in the Power system gives no energy to outside and causes enlargement of power apparatus, voltage fluctuation and unstability of power system. The power conversion system and control system which are composed of power semiconductor devices such as Thyrisor, transistor, GTO and so on have been appeared as new sources of Harmonics. So the reduction of harmonics in power semiconductor system is one of impending problems on the point of energy conservation and improvement of power factor. This paper treates the fundamental review of the harmonics reduction by Current type PWM-Inverter. This Inverter-detects not only the fundamental wave but also that of all harmonics created in the power semiconductor system and is scheduled to control by sampled value.

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FUNDAMENTAL RESEARCH OF A NOVEL 3/1 PHASE CONVERTER FOR ELECTRIFIED RAILROAD

  • Farshad, Siamak;Rongtai, Hao
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.955-960
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    • 1998
  • Electrified railroads inject large amount of harmonics, negative sequence and reactive currents to electric supply systems. This paper introduces application of active filter as a 3/1 phase converter for electrified railroad. In this system active filter compensate harmonics, negative sequence and reactive currents and electric railroad and active filter together act as a balance three-phase load with power factor 1

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Study on the Variation of Reactive Power When Applying the Passive Filter (수동형 필터 적용시 무효전력의 변화에 관한 연구)

  • Kim, Ji-Myeong;Kim, Jong-Gyeum
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.9
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    • pp.1626-1631
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    • 2016
  • Generally, the low-voltage customer has been used with a linear load and nonlinear load in the 3-phase 4-wire distribution system. Linear load has usually configured the resistance and inductance, current phase is slower than the voltage phase, so power factor is low. It is required for the power factor correction device prior to the phase of the current than the voltage. The capacitor is connected in parallel to the load in order to ensure a low power factor. Power converter such as an inverter is a typical non-linear load. Non-linear load generates harmonic currents in the energy conversion process. Many electrical equipment may be adversely affected by the harmonic current. There, passive or active filter have been used to reduce these harmonics current. Passive filter consisting of inductor and capacitor generates a reactive power. According to the combination of filter inductor and capacitor, reactive power can be adjusted. In this paper, we analyzed how the combination of inductor and capacitor affects the overall power factor by simulation and measurement.

A Study on Development of SVC to Improve Harmonics and Power Factor of Power Plant (발전소 소내전력 고조파 및 역률 개선용 SVC 개발에 관한 연구)

  • Yun, Gwang-Hee;Lee, Hee-Jin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.11
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    • pp.2109-2118
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    • 2011
  • The power system has to maintain its synchronism from transient disturbances and oscillations. To achieve this, the static var compensator(SVC), which is a flexible AC transmission system(FACTS), is applied to the power system. SVC using an advanced control algorithm improves the stability of power system. This paper is a study on design of SVC to improve harmonics and power factor of power plant. The proposed SVC analyzes harmonics, voltage drop and reactive power in real time. On the basis of the analysis of the data, the SVC using a switching control algorithm decreases harmonic signals and increases the power factor. The experimental results show that the proposed SVC enhances the stability of power system.

Using Voltage Control Active Power Filter, Power Factor Improvement and Harmonics Reduction for Nonlinear Load (전압제어형 능동전력필터를 이용한 비선형부하의 고조파저감 및 역류개선)

  • 김병진;문학룡;송양희;임병국;전희종
    • The Transactions of the Korean Institute of Power Electronics
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    • v.5 no.4
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    • pp.403-408
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    • 2000
  • In this paper, voltage control APF(Active Power Filter) is introduced to improve power factor and reduce harmonics generated from nonlinear load. The voltage controlled APF which is consisted of inverter and passive filter operates with nonlinear load simultaneously. Real power supplies from main power to load and reactive power provides from APF to load. According to the results o experiment and simulation, it is proved that the proposed system has the performance of improving power factor and reducing harmonics.

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A Study on the Single Phase Voltage-Controlled Active Power Filter for Power Quality Improvement (전력품질 개선을 위한 단상 전압제어형 능동전력필터 시스템에 관한 연구)

  • 손진근
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.5
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    • pp.238-245
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    • 2003
  • In this paper, a single Phase voltage source voltage-controlled active power filter(APF) for power quality improvement was proposed. The proposed APF has the performance of harmonic suppression and unity power factor correction. The performance of harmonic suppression can be obtained by controlling the waveshape of the APF output voltage to be sine wave. And, unity power factor is controlled by the reactive power control loop of the APF output. Simulation and experimental results using diode rectifier showed that the voltage-controlled APF, unlike the current-controlled APF, can reduce the voltage harmonics as well as current harmonics. Also the results showed that the input dover factor and power quality were greatly improved.

Development of Current Harmonics Estimation Method by Considering the Characteristics of Input Voltage (인가전압의 특성을 고려한 주거용 부하의 전류성분 추정기법 개발)

  • Ji, Pyeong-Shik
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.60 no.4
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    • pp.181-185
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    • 2011
  • Due to the increasing of nonlinear loads such as converters and inverters connected to the electric power distribution system, and extensive application of harmonic generation sources with power electronic devices, disturbance of the electric power system and its influences on industries have been continuously increasing. Thus, it is difficult to construct accurate load model for active and reactive power in environments with harmonics. In this research, we develop current harmonics estimation method based on Extreme Learning Machine (ELM) with fast learning procedure for residential loads. Using data sets acquired from various residential loads, the proposed method has been intensively tested. As the experimental results, we confirm that the proposed method makes it possible to effective estimate current harmonics for various input voltage.