• Title/Summary/Keyword: THD(total harmonic distortion)

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A Study on the Analysis on the Direct-Driven High Power Permanent Magnet Generator for Wind Turbine

  • Kim, Ki-Chan;Ihm, Hyung-Bin;Lee, Ju
    • 조명전기설비학회논문지
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    • 제22권3호
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    • pp.88-95
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    • 2008
  • In the paper, the permanent magnet synchronous generator of 1.5[MW] output power which is driven directly without gear system is designed by conventional magnetic equivalent circuit method and analyzed by finite element method. We analyzed the characteristics of generator like no load, rated load, short circuit condition and demagnetization of permanent magnet in order to verify the design results by magnetic circuit method. The last, the analysis results of two kinds of rotor types are compared with each other. Especially the THD(total harmonic distortion) of output voltage is examined for the comparison.

출력전압 레벨 수와 전류정격을 고려한 PWM 다중레벨 인버터 (Multi-level PWM Inverter Considering the number of Output Voltage level and Current rating)

  • 박노식;서종준;박성준;김광헌;조수억;김철우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2005년도 전력전자학술대회 논문집
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    • pp.659-662
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    • 2005
  • In this paper, we proposed the novel hybrid multi-level inverter using combination of the output voltage of transformers to reduce the THD(Total Harmonic Distortion) and improve the waveform of output voltage. The proposed multi-level inverter used the output of transformer which is 1times, 2times, 4times of input of the transformers. So we increased the output voltage from the reduce the number of switching component and transformer. Also, we tested the proposed prototype 15-level inverter to clarify the proposed electric circuit and reasonableness of control signal for the proposed multi -level PWM inverter.

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위상 변위제어기법을 이용한 저주파 다중레벨 스위칭 방식 (Low frequency Multi-level Switching Strategy based on Phase-Shift Control)

  • 우도;문채주;박성준;남해곤;권순재
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2005년도 전력전자학술대회 논문집
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    • pp.673-676
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    • 2005
  • In this paper, we proposed the electric circuit using one common arm of H-Bridge Inverters to reduce the number of switching component in multi-level inverter combined with H-Bridge Inverters and Transformers. and furthermore we suggested the new multi-level PWM inverter using PWM level to reduce THD(Total Harmonic Distortion). and we used the switching method that can be same rate of usage at each transformer. Also, we tested the proposed prototype 9-level inverter to clarify the proposed electric circuit and reasonableness of control signal for the proposed multi-level PWM inverter.

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Analysis and Design of a PFC AC-DC Converter with Electrical Isolation

  • Lin, Chia-Ching;Yang, Lung-Sheng;Zheng, Ren-Jun
    • Journal of Power Electronics
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    • 제14권5호
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    • pp.874-881
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    • 2014
  • This study presents a single-phase power factor correction AC-DC converter that operates in discontinuous conduction mode. This converter uses the pulse-width modulation technique to achieve almost unity power factor and low total harmonic distortion of input current for universal input voltage $90V_{rms}$ to $264V_{rms}$) applications. The converter has a simple structure and electrical isolation. The magnetizing-inductor energy of the transformer can be recycled to the output without an additional third winding. The steady-state analysis of voltage gain and boundary operating conditions are discussed in detail. Finally, experimental results are shown to verify the performance of the proposed converter.

Comparative Analysis of Three-Phase AC-DC Converters Using HIL-Simulation

  • Raihan, Siti Rohani Sheikh;Rahim, Nasrudin Abd.
    • Journal of Power Electronics
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    • 제13권1호
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    • pp.104-112
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    • 2013
  • This paper presents a comparative evaluation of various topologies for three-phase power converters using the hardware-in-the-loop (HIL) simulation technique. Various switch-mode AC-DC power converters are studied, and their performance with respect to total harmonic distortion (THD), efficiency, power factor and losses are analyzed. The HIL-simulation is implemented in an Altera Cyclone II DE2 Field Programmable Gate Array (FPGA) Board and in the Matlab/Simulink environment. A comparison of the simulation and HIL-simulation results is also provided.

3상 인버터를 위한 동기좌표계에서의 위치기반 데드타임 보상알고리즘 (Dead-time compensation algorithm on synchronous frame for 3-phase inverter)

  • 임정우;조영훈
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2018년도 전력전자학술대회
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    • pp.27-29
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    • 2018
  • 본 논문은 상 전류의 위치(전기각)를 기반으로 보상전압을 결정하는 새로운 데드타임 보상알고리즘을 제안한다. 제안하는 알고리즘은 보상전압을 결정하는데 있어, 전류의 극성대신 제어하는 상 전류의 위치(전기각)를 이용하기 때문에 추가적인 알고리즘 없이 간단하게 보상전압을 정의할 수 있다. 또한 제안하는 데드타임 보상알고리즘은 동기좌표계에 바로 적용가능하기 때문에 3상 전압형 인버터(VSIs; Voltage Source Inverters)에 일반적으로 사용되는 동기좌표기반 제어기에 적용이 용이하고 추가적인 변환과정 없이 동기좌표에서의 인버터 출력전압을 추정할 수 있다. 제안하는 데드타임 보상알고리즘의 효과와 성능을 검증하기 위하여 전압형 3상 인버터를 이용한 L-R부하 실험이 진행되었으며, 상 전류파형의 FFT(Fast Fourier Transfrom)와 THD(Total Harmonic Distortion)를 산정하여 정량적 분석을 병행하였다.

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Hartley-VCO Using Linear OTA-based Active Inductor

  • Jeong, Seong-Ryeol;Chung, Won-Sup
    • 전기전자학회논문지
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    • 제19권4호
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    • pp.465-471
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    • 2015
  • An LC-tuned sinusoidal voltage-controlled oscillator (VCO) using temperature-stable linear operational transconductance amplifiers (OTAs) is presented. Its architecture is based on Hartley oscillator configuration, where the inductor is active one realized with two OTAs and a grounded capacitor. Two diode limiters are used for limiting amplitude. A prototype oscillator built with discrete components exhibits less than 3.1% nonlinearity in its current-to-frequency transfer characteristic from 1.99 MHz to 39.14 MHz and $220ppm/^{\circ}C$ frequency stability to the temperature drift over 0 to $75^{\circ}C$. The total harmonic distortion (THD) is as low as 4.4 % for a specified frequency-tuning range. The simulated phase noise of the VCO is about -108.9 dBc/Hz at 1 MHz offset frequency in frequency range of 0.4 - 46.97 MHz and property of phase noise of VCO is better than colpitts-VCO.

패널용 에어컨의 역률 개선 및 고조파 저감 (Power Factor Correction Improvement and Total Harmonic Distortion Reducing for Panel's Air-conditioner)

  • 박성우;박정우;이현우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.258-261
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    • 2001
  • High Power factor Active Filter converter is used for Inverter Air conditioner power supply to meet IEC standard. In the active filter topology for power factor, extra switch just control the input current indirectly to meet the IEC standard for reducing the cost and size. In this paper, low cost converter was suggested by simulation using extra switch which auxiliary pulse is inserted and quasi resonant soft switching topology control is adapted for panel's inverter air conditioner converter Inserting auxiliary Pulse method to the extra switch has the benefit of reducing THD by low cost input control circuit. And also quasi resonant soft switching topology can reduce switching loss. So both technical is suitable for Panel's Air conditioner.

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Comparative Study on SVPWM Switching Sequences for VSIs

  • Vivek, G.;Biswas, Jayanta;Nair, Meenu D.;Barai, Mukti
    • Journal of Electrical Engineering and Technology
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    • 제13권1호
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    • pp.133-142
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    • 2018
  • Paper presents a comparative study of space vector pulse width modulation (SVPWM) switching sequences for Voltage Source Inverters (VSIs). Various SVPWM switching sequences are studied for two and three level VSIs in linear modulation index region. The computations of dwell times are presented for two and three level VSIs based on space vector geometry in a synchronized and optimized manner. The existing SVPWM switching sequences are implemented using Matlab / Simulink and in an experimental setup for three phase two and three level VSIs. The simulation and experimental waveforms of conventional SVPWM (CSVPWM) and bus clamped SVPWM (BCSVPWM) are demonstrated for two and three level inverter respectively. The performance of different SVPWM switching sequences are evaluated and presented based on weighted voltage total harmonic distortion (THD).

A Hysteresis Current Controller for PV-Wind Hybrid Source Fed STATCOM System Using Cascaded Multilevel Inverters

  • Palanisamy, R.;Vijayakumar, K.
    • Journal of Electrical Engineering and Technology
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    • 제13권1호
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    • pp.270-279
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    • 2018
  • This paper elucidates a hysteresis current controller for enhancing the performance of static synchronous compensator (STATCOM) using cascaded H-bridge multilevel inverter. Due to the rising power demand and growing conventional generation costs a new alternative in renewable energy source is gaining popularity and recognition. A five level single phase cascaded multilevel inverter with two separated dc sources, which is energized by photovoltaic - wind hybrid energy source. The voltages across the each dc source is balanced and standardized by the proposed hysteresis current controller. The performance of STATCOM is analyzed by connecting with grid connected system, under the steady state & dynamic state. To reduce the Total Harmonic Distortion (THD) and to improve the output voltage, closed loop hysteresis current control is achieved using PLL and PI controller. The performance of the proposed system is scrutinized through various simulation results using matlab/simulink and hardware results are also verified with simulation results.