• Title/Summary/Keyword: Harmonics sensitivity

Search Result 29, Processing Time 0.022 seconds

Characteristics on the Harmonic Sensitivity of an Induction Watthour Meter (유도형 적산전력량계의 고조파 민감도 특성)

  • Jang, Seok-Myeong;Lee, Seong-Ho;Park, Yeong-Tae
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.48 no.11
    • /
    • pp.587-596
    • /
    • 1999
  • The use of Switching elements in power systems causes the current or voltage to involve harmonic waves. Harmonics bring about registration errors of the equipment for measuring power. In case the induction watthour meter designed on sinusoidal source is used in the measurement of power with harmonics, the precise measurement of power has many problems because harmonics cause a decrease of power factor and vibration by the unstable driving force on the aluminum disc. In this paper, analysis and test results on the harmonic sensitivity of an induction watthour meter is reported when the input voltage and current with harmonics were supplied to single-phase watthour meter.

  • PDF

Characteristics on the Harmonic Sensitivity of Induction Watthour Meter (유도형 적산전력량계의 고조파 민감도 특성)

  • Jang, Seok-Myeong;Lee, Sung-Ho;Park, Young-Tae
    • Proceedings of the KIEE Conference
    • /
    • 1998.11a
    • /
    • pp.31-33
    • /
    • 1998
  • The sensitivity of induction watthour meter was reviewed by characteristic tests under the effects of each input harmonics and the variation of power factor of inverter input/output terminal. This paper presents experimental data on the characteristics of induction watthour meter under the effect of harmonics.

  • PDF

A Technique of Deterioration Diagnosis for ZnO Element by Analyzing the 3rd order Harmonics- of Leakage Current (누설전류의 제3고조파 분석에 의한 ZnO소자의 열화진단기술)

  • Lee, Bok-Hee;Kang, Sung-Man
    • Proceedings of the KIEE Conference
    • /
    • 1998.07e
    • /
    • pp.1740-1742
    • /
    • 1998
  • This paper describes the technique of deterioration diagnosis for ZnO element. Due to the non-linear resistance of ZnO block, the total leakage current contains harmonics when arrester deteriorated. The most significant harmonics is the 3rd order component. So, it can be used as an indicator of the arrester condition. An iron core, which has a very high relative permeability, is used for increasing detection sensitivity and the 3th order harmonics of leakage current was detected by band-pass circuit. And we have verified the reliability and performance of the sensing device through several laboratory tests.

  • PDF

2-Dimensional Fluxgate Sensor using Ferrite Ring Core (페라이트 링코어를 이용한 2차원 Fluxgate 센서)

  • 임재환;박한석;안영주;김남호;류지구
    • Proceedings of the Korea Institute of Convergence Signal Processing
    • /
    • 2003.06a
    • /
    • pp.251-255
    • /
    • 2003
  • In this paper, we have a fluxgate sensor with ferrite core. Thought sensor is consist of one excitation coil and two pick-up coil, and A lock-in amplifier circuity is designed for Signal processing of picking up 2nd harmonics from pick-up coils. Excitation coils is turned by 20 turns, and pick-up coil for picking up harmonics is turned by 40 turns eachother. It convert 2nd harmonics to DC output voltage. Measured output voltage and sensitivity, direction of sensor about out side magnetic field, and also sensor output properties about excitation frequency and current.

  • PDF

An Analysis and Optimum Design of o Neutral Line Harmonics Eliminating Reactor (중성선 영상고조파 저감용 특수 Reactor 최적설계 연구)

  • Shin, Pan-Seok;Chung, Gyo-Bum;Kim, Han-Deul;Kim, Cheol
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.20 no.5
    • /
    • pp.33-41
    • /
    • 2006
  • In the modem power distribution systems, there are lots of zero-phase current harmonics in the neutral power line due to much usages of the controlled switching devices, various semiconductor power converting systems, OA(Office Automation) equipments, PC etc. In order to minimize the current harmonics a zero-phase neutral line current eliminating reactor (NHER) is designed and analyzed its performance using the finite element program. For the design of NHER a program is developed using C++ program. To verify the program a case model(380/220[V], 200[A]) is designed and analyzed by the developed program. As the results of the optimal design, the core loss is reduced by 26[%] with eliminating of the current harmonics. Especially the ninth harmonics is much reduced as compared with the others. When the design of NHER is adapted to the load of the power system, the eliminating effect and efficiency of the device will be much better

DC Current Transducer Using Saturable Magnetic Cores (포화자성코어를 이용한 직류전류측정 트랜스듀서)

  • Park, Young-Tae;Jung, Jae-Kap;Gang, Jeon-Hong;Ryu, Kwon-Sang;Yu, Kwang-Min
    • Journal of the Korean Magnetics Society
    • /
    • v.14 no.4
    • /
    • pp.138-142
    • /
    • 2004
  • Uncertainty and characteristics of the developed current sensor by means of two identically wound magnetic cores forming a ring like for measurement of a low DC current such as leakage current was described in this paper. This transducer consists of a sensor type of a current transformer, peak value detectors, a reference alternating low frequency voltage oscillator, precision measuring circuits to measure the output signals of sensor with harmonics, and can be measured up to 2 A at DC current. The resolution and sensitivity of the sensor were 0.1㎃ and 10㎷/㎃, respectively.

A Study on the Harmonics Effect of Ratio Differential Relay for Transformer Protection (변압기 보호용 비율차동계전기의 고조파 영향에 관한 연구)

  • Kim, Kyung-Chul;Hwang, Young-Rok;Kho, Hun;Jung, Dong-Won;Chung, Hae-Sung;Lee, Dong-Wook;Jeong, Chae-Ho;Lee, Jae-Yoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.28 no.6
    • /
    • pp.99-105
    • /
    • 2014
  • Power transformers are applied throughout the power system to connect systems of different voltage to one another. Since a ratio differential relay offers high sensitivity in detection of internal faults in power transformers, it is widely used in the main protection system. The use of nonlinear devices such as rectifiers and other devices utilizing solid state switching have been increased in industry during recent years. For nonlinear loads, the load current is not proportional to the instantaneous voltage. This situation creates harmonic distortion on the system. The harmonic could differential relay misoperation if not recognized. This paper aims at analyzing and probing into the influences of harmonics on a ratio differential relay for power transformer protection.

Decoupling Method Between Digital Signals on FPCB and Mobile Handset Antenna

  • Kim, Joon-Chul;Kim, Hyeong-Dong
    • ETRI Journal
    • /
    • v.33 no.1
    • /
    • pp.121-124
    • /
    • 2011
  • Digital harmonics, which may reduce the radio frequency sensitivity of a system, can be coupled with an antenna in a mobile handset. This letter presents a decoupling method for increasing the isolation between digital harmonics on a flexible printed circuit board (FPCB) and an antenna in terms of the ground mode current and the concept of reaction. We model the signal and ground lines in an FPCB as a loop circuit exciting a ground mode current and demonstrate a simple but efficient decoupling method for reducing the excited ground mode current.

Reconfigurable Selective Harmonic Elimination Technique for Wide Range Operations in Asymmetric Cascaded Multilevel Inverter

  • Kavitha, R;Rani, Thottungal
    • Journal of Power Electronics
    • /
    • v.18 no.4
    • /
    • pp.1037-1050
    • /
    • 2018
  • This paper presents a novel reconfigurable selective harmonic elimination technique to control harmonics over a wide range of Modulation Indexes (MI) in Multi-Level Inverter (MLI). In the proposed method, the region of the MI is divided into various sectors and expressions are formulated with different switching patterns for each of the sectors. A memetic BBO-MAS (Biogeography Based Optimization - Mesh Adaptive direct Search) optimization algorithm is proposed for solving the Selective Harmonic Elimination - Pulse Width Modulation (SHE-PWM) technique. An experimental prototype is developed using a Field Programmable Gate Array (FPGA) and their FFT spectrums are analyzed over a wide range of MI using a fluke power logger. Simulation and experimental results have validated the performance of the proposed optimization algorithms and the reconfigurable SHE-PWM technique. Further, the sensitivity of the harmonics has been analyzed considering non-integer variations in the magnitude of the input DC sources.

A Clamp Type Sensor for AC/DC Low Current Measurement (클램프 형 직교류 저 전류 측정 센서)

  • 박영태;유광민
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.15 no.12
    • /
    • pp.1045-1053
    • /
    • 2002
  • This paper describes characteristics of the developed current sensor by means of two identically wound magnetic cores forming a clamp like for measurement of a low DC, or AC current. This sensor consists of peak value detectors, a sensor of an electrically compensated current transformer type, a reference alternating voltage, Precision measuring circuits to measure the output signals of sensor with harmonics, and can be measured up to 2 A at DC, or AC current. The current sensor shows a measurement accuracy of less than 0.3% in the frequency range 40 Hz - 10 HBz. The resolution and sensitivity of the sensor were evaluated 0.1 mA and 10 mV/mA, respectively.