A New Three-Phase Parallel Active Power Filter with Outages and PCC Voltage Compensation

A New Three-Phase Parallel Active Power Filter
with Outages and PCC Voltage Compensation
by
WOO-CHEOL, LEE
Under the supervision of
Prof. DONG-SEOK HYUN, Ph.D.
Dept. of Electrical Engineering
The Graduate School of Hangyang University
This paper is a research on a new three-phase parallel active
power filter with outages and PCC voltage compensation under the
utility problems caused by the proliferation of non-linear loads such
as harmonics, increment of reactive power, voltage variation, and
blackouts. For these purposes, this paper presents (i) the optimal
design of parallel active power filter (ii) the modified PWM
modulation strategy which can operate the power conversion
system by using the single current sensor (iii) the detection method
of negative sequence and control scheme under the unbalanced load
condition (iv) the control method of constant PCC voltage (v) UPS
control method caused by blackouts in typical distribution systems
and the relations of each scheme.
 In a design method of the parallel active filter, an analytic model
on active filter is proposed. For this purpose, control circuit, power
 circuit, IGBT drive, and design method of the passive filter are
proposed. In a modified PWM modulation strategy, a technique for
reconstructing converter line currents using the information from a
single current sensor in the DC-link of a converter and comparative
evaluation of the performance of single sensor control techniques in
the DC-link for voltage-source PWM converters is presented. And
when 3f input currents cannot be reconstructed, three methods to
acquire the DC-link current are also proposed.
LINK
https://www.mediafire.com/?1u16ro18vksutdg

Design of Advanced Voltage Controller for Three-Phase UPS inverters by KYUNG-HWAN KIM

Design of Advanced Voltage Controller for
Three-Phase UPS inverters
by
KYUNG-HWAN KIM
Under the supervision of
Prof. DONG-SEOK HYUN, Ph.D.
Dept. of Electrical Engineering
The Graduate School of Hanyang University
 ABSTRACT

Inverter system, which uses LC component as the output filter, is essential for a UPS (Uninterruptible Power supply), UPQC (Universal Custom Power Conditioner) and PCS (Power Conditioning System) for the photovoltaic power system. This paper presents DSP (Digital Signal Processor) controlled voltage controller for a 3-phase UPS inverter, which is able to compensate the voltage distortions due to unbalanced and nonlinear loads. The paper discussed the problem of conventional control schemes for the compensation of voltage distortion when they are applied to UPS inverter, and proposes advanced synchronous reference frame control scheme which is able to overcome the problem. In order to solve the problem of low damping ratio of LC filter, the inverter current feed-forward compensator including the selection of the feed-forward gain is proposed. And the digital filter for a compensation of the voltage distortion due to unbalanced and nonlinear loads is also proposed, which makes PI controllers in the synchronous reference frame are able to operate with DC values even under nonlinear and unbalanced load, likewise ensures PI controllers are able to provide zero steady state error. In order to improve the practical usability of the proposed scheme in the paper, the realization of the PLL and the parallel operation, which are essential for UPS, using the proposed controller is also presented. Especially, this paper shows that the feed-forward compensation of the inverter current and the PWM synchronization method proposed in the paper ensures a high precise load-sharing performance in parallel operation of inverter system. The effectiveness of the proposed scheme has been investigated and verified in digital simulation. This thesis also investigates the digital implementation of the proposed systems and all of the related theoretical concepts and control systems have been verified in experimental prototype of the UPS systems.
LINK THESIS
http://library-english.hanyang.ac.kr/eng/index.jsp
DOWNLOAD
https://www.mediafire.com/?vyf940qs5fcc55l

CONDICIONAMENTO DE ENERGIA E GRUPOS GERADORES REVISTA SETOR ELETRICO NOVEMBRO 2013-PARTE1

MANTENIMIENTO INGENIERIA ELECTRICA CHINA

3 Replacing a junior electrician cross arm on 10KV line and tie on a porcelain line (power) 4 with a digital multimeter to determine power transistor using a digital multimeter pin 5 to determine the three small power transistor 6 pin electrical degrees

视频: 电工标准操作4 Vídeo: estándar electricista funcionamiento 4

Video: Electric Standard Operating TEST

ELECTRIC TEST ENGINEERING

IPESI COMUNICAÇÃO A SERVIÇO DA TECNOLOGIA NOV/DEC2013

IPESI-EI-188

Publish at Calameo or read more publications.

RWTH Aachen University Clase Abierta: Fabricación de Maquinaria

China's moon rover separates from moon lander

CHINA ATERIZOU COM SUCESSO SUA PRIMEIRA SONDA ESPACIAL NÃO TRIPULADA NA LUA,CHINA E APENAS O TERCEIRO PAIS A POUSAR NA LUA,SEGUINDO OS EUA E A ANTIGA UNIÃO SOVIETICA,QUE TANTO REALIZOU AS TAREFAS DECADAS ATRAS. "E UMA CONQUISTA DIGNA DE RESPEITO",DISSE JOHN LOGSDON,PROFESSOR EMERITO DA UNIVERSIDADE DE GEORGE WASHINGTON,QUE HA MUITO TEM MONITORADO POLITICA ESPACIAL.
'CHANG-3 E IMPRESSIONANTE COMO O PRIMEIRO POSSO NA LUA EM QUASE QUATRO DECADAS,CAINDO EM UM LUGAR QUE NÃO FOI EXPLORADO E USANDO INSTRUMENTAÇÃO CIENTIFICA RELATIVAMENTE AVANÇADA.

Analysis of the Internal Electrical Characteristics of Electronic Power Transformers Yang Yi*, Cheng-Xiong Mao*, Dan Wang†, and Ji-Ming Lu**

Analysis of the Internal Electrical Characteristics of Electronic Power Transformers Yang Yi*, Cheng-Xiong Mao*, Dan Wang†, and Ji-Ming Lu** *State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, China †**College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, China.
Abstract The modularized subunit of an electronic power transformer (EPT) is a series connection of two H-bridge voltage-source converters and a DC–DC converter with a high-frequency isolation transformer (HFIT). On the basis of cascading and paralleling the modularized subunits, EPT can be used in high-voltage and large-current applications in the power system. This paper discusses the steady state analysis of the modularized subunit of EPT. Theoretical analysis considers the influences of the two H-bridge voltage-source converters on the two sides of the DC–DC converter. We deduce the formulas of the theoretical calculation on the internal electrical characteristics of EPT (e.g., the voltages of the DC-bus capacitor and the primary side peak current of the HFIT). This paper provides guidance on the design and selection of EPT key elements (e.g., the DC-bus capacitors and HFIT). Experimental results are obtained from a single subunit of a laboratory model rated at 962 V, 15 kVA. All calculations, simulations,and experiments confirm the theoretical analysis of the subunit of EPT.
LINK
 http://jpe.or.kr/archives/view_articles.asp?seq=776

New Isolated Single-Phase AC-DC Converter for Universal Input Voltage Ming-Rong Lee*, Lung-Sheng Yang†, and Chia-Ching Lin*

New Isolated Single-Phase AC-DC Converter for Universal Input Voltage Ming-Rong Lee*, Lung-Sheng Yang†, and Chia-Ching Lin* *†Dept. of Electrical Engineering, Far East University, Tainan City, Taiwan Abstract This paper investigates a new isolated single-phase AC-DC converter, which integrates a modified AC-DC buck-boost converter with a DC-DC forward converter. The front semi-stage is operated in discontinuous conduction mode (DCM) to achieve an almost unity power factor and a low total harmonic distortion of the input current. The rear semi-stage is used for step-down voltage conversion and electrical isolation. The front semi-stage uses a coupled inductor with the same winding-turn in the primary and secondary sides, which is charged in series during the switch-on period and is discharged in parallel during the switch-off period. The discharging time can be shortened. In other words, the duty ratio can be extended. This semi-stage can be operated in a larger duty-ratio range than the conventional AC-DC buck-boost converter for DCM operation. Therefore, the proposed converter is suitable for universal input voltage (90~264 Vrms) and a wide output-power range. Moreover, the voltage stress on the DC-link capacitor is low. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.
 LINK
http://jpe.or.kr/archives/view_articles.asp?seq=760

Modeling and Control Method for High-power Electromagnetic Transmitter Power Supplies Fei Yu† and Yi-ming Zhang*

Modeling and Control Method for High-power Electromagnetic Transmitter Power Supplies Fei Yu† and Yi-ming Zhang* †*College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing, China
LINK
http://jpe.or.kr/archives/view_articles.asp?seq=769

Study on the Influence of Distribution Lines to Parallel Inverter Systems Adopting the Droop Control Method Xuan Zhang*, Jinjun Liu*, Zhiyuan You†, and Ting Liu*

Study on the Influence of Distribution Lines to Parallel Inverter Systems Adopting the Droop Control Method Xuan Zhang*, Jinjun Liu*, Zhiyuan You†, and Ting Liu* *†Dept. of Electronic Engineering, Xi’an Jiaotong University, Xi'an, China Abstract This paper takes into account the influence of the different impedances of distribution lines on power distribution among inverters when the inverters are paralleled with the droop control method. The impact of distribution lines on the power distribution of inverters can be divided into two aspects. Firstly, since the distributed generators are in low voltage grids, there is resistive impedance in the distribution lines, which will cause control coupling and reduce system stability. The virtual negative resistive impedance of inverters is adopted in this paper to neutralize the resistive element of distribution lines and thus make the distribution line impedance purely inductive. Secondly, after solving the resistive impedance problem, the difference in the inductive impedance value of distribution lines due to the low density of distributed generators will cause an unequal share of reactive power. With regards to this problem, modification is put forward for the droop control strategy to share the reactive power equally. The feasibility of the design is validated by simulation and experimental results.
LINK
http://jpe.or.kr/archives/view_articles.asp?seq=771

Control Method for Reducing the THD of Grid Current of Three-Phase Grid-Connected Inverters Under Distorted Grid Voltages

Control Method for Reducing the THD of Grid Current of Three-Phase Grid-Connected Inverters Under Distorted Grid Voltages Thanh-Vu Tran*, Tae-Won Chun†, Hong-Hee Lee*, Heung-Geun Kim**, and Eui-Cheol Nho*** *†Dept. of Electrical Engineering, University of Ulsan, Ulsan, Korea **Dept. Of Electrical Engineering, Kyungpook National University, Daegu, Korea ***Dept. of Electrical Engineering, Pukyong National University, Busan, Korea
Abstract This paper proposes a control method for reducing the total harmonic distortion (THD) of the grid current of three-phase grid-connected inverter systems when the grid voltage is distorted. The THD of the grid current caused by grid voltage harmonics is derived by considering the phase delay and magnitude attenuation due to the hardware low-pass filter (LPF). The Cauchy-Schwarz inequality theory is used in order to search more easily for the minimum point of the THD. Both the gain and angle of the compensation voltage at the minimum point of the THD of the grid current are derived with the variation of cut-off frequencies of the hardware LPF. Simulation and experimental results show the validity of the proposed control methods.
LINK
 http://jpe.or.kr/archives/view_articles.asp?seq=772

The Effect of Transformer Leakage Inductance on the Steady State Performance of Push-pull based Converter with Continuous Current Qian Chen†, Trillion Q. Zheng*, Yan Li*, and Tiancong Shao*

The Effect of Transformer Leakage Inductance on the Steady State Performance of Push-pull based Converter with Continuous Current Qian Chen†, Trillion Q. Zheng*, Yan Li*, and Tiancong Shao* †*School of Electrical and Engineering, Beijing Jiaotong University, Beijing, China Abstract As a result of the advantages such as high efficiency, continuous current and high stability margin, push-pull converter with continuous current (PPCWCC) is competitive for battery discharge regulator (BDR) which plays an important role in power conditioning unit (PCU).Leakage inductance yields current spike in low-ripple current of PPCWCCs. The operating modes are added due to leakage inductance. Therefore the steady state performance is affected, which is embodied in the spike of low-ripple current. PPCWCCs which are suitable for BDR can be separated into three types by current spike characteristics. Three representative topologies IIs1, IIcb2 and Is3 are analyzed in order to investigate the factors on the magnitude and duration of spike. Equivalent current sampling method (ECSM) which eliminates the sampling time delay and achieves excellent dynamic performance is adopted to prevent the spike disturbance on current sampling. However, ECSM reduces the sampling accuracy and telemetry accuracy due to neglecting the spike. In this paper, ECSM used in PPCWCCs is summarized. The current sampling error is analyzed in quality and quantity, which provides the foundation for offsetting and enhancing the telemetry accuracy. Finally, current sampling error rate of three topologies is compared by experiment results, which verify the theoretical analysis.
LINK
http://jpe.or.kr/archives/view_articles.asp?seq=735

Design of an LCL-Filter for Three-Parallel Operation of Power Converters in Wind Turbines Hae-Gwang Jeong*, Dong-Keun Yoon**, and Kyo-Beum Lee†

Design of an LCL-Filter for Three-Parallel Operation
of Power Converters in Wind Turbines
Hae-Gwang Jeong*, Dong-Keun Yoon**, and Kyo-Beum Lee†
†*Department of Electrical and Computer Engineering, Ajou University, Suwon, Korea
**Research Group, LG Innotek Co., Ltd., Ansan, Korea

This paper proposes a design scheme for an LCL-filter used for the three-parallel operation of the power converters in high-capacity wind turbines. The designs of the power devices and grid connected filter are difficult due to the high level voltages and currents in huge-capacity wind turbines. To solve these problem, this paper presents three-parallel operation and LCL-filter design techniques optimized by parallel operation. Furthermore, the design of an inverter side inductance of the LCL-filter is discussed in detail considering the switching modulation method. Simulation and experimental results demonstrate the validity of the designed filter and wind turbines.
LINK
http://jpe.or.kr/archives/view_articles.asp?seq=744
https://www.mediafire.com/?f2tlal6acrdao3a

GRAU DE PROTEÇÃO IP PARA EQUIPAMENTOS ELÉTRICOS

Parallel Operation of Three-Phase Four wire UPS using Droop Control ( Hyunseob Kim․Jungho Han․Joong-Ho Song )

Parallel Operation of Three-Phase Four wire UPS using Droop Control

* Main author：Dept. of Railway Electrical and
Signaling Engineering, Seoul National
University of Science and Technology,
Candidate of MS
** Corresponding author：Dept. of Electrical and
Information Engineering, Seoul National
University of Science and Technology,
Professor
Tel：02-970-6415, Fax：02-978-2754
E-mail：joongho@seoultech.ac.kr
 Abstract
A new droop control method which can be applied to 3-phase 4-wire uninterruptible power supply is
proposed in this paper. The droop control method for parallel operation is very attractive one as UPS
parallel operation can be carried out without any data communication devices provided among UPS
systems connected, but it reportedly shows a PnP(plug-and-play) problem. A basic reason why a
circulating current could flow among parallel-connected UPS systems is clearly investigated as well
when droop-controlled-ups systems are operated in the manner of PnP. The proposed algorithm is
deduced from the investigated result and is basically structured to keep a balanced frequency and
balanced voltage profile against power variation. This paper shows that balanced parallel operation of
droop control method can be obtained under unbalanced load as well as balanced load conditions .when PnP operation is needed and load change occurs.
LINK
http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=JMJGCE_2013_v27n4_88

https://www.mediafire.com/?gyedgrq3fd38alx

Power Factor Correction of Single-phase Boost Converter for Low-cost Type UPS Configuration Jong-Chan Park․Jin-Geun Shon

Power Factor Correction of Single-phase Boost Converter for Low-cost Type UPS Configuration 박 종 찬*․손 진 근† (Jong-Chan Park․Jin-Geun Shon) The Transactions of the Korean Institute of Electrical Engineers Vol. 62P, No. 3, pp. 145～150, 2013

 Abstract -A novel AC to DC PWM converters with unity input power factor are proposed to overcome the above shortcoming. The main function of these converters is to shape the input line current to force it exactly in phase with the input AC voltage. Therefore, the input power factor can be improved to near unity and the input current harmonics can be eliminated. In this paper, half-bridge converter with two active switches and two diodes are utilized for low-cost type UPS configuration. By having only two semiconductors in the current path at any time, losses can be reduced over the conventional boost topology. Also, this converter provides controllable dc-link voltage, high power factor, and low cost type converter by simple power circuits. Simulation results show that the proposed half-bridge converter/inverter control technique can be applied to single-phase low-cost type UPS systems successfully.
LINK
http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=DHJGHA_2013_v62n3_145

https://www.mediafire.com/?fqu14xattw5nwkp

LLC Resonant Converter design for Uninterruptible Power Supply Battery Discharger

LLC Resonant Converter design for Uninterruptible Power Supply Battery
Discharger
Kwang-Min Yoo1, Seung-Joo Kim1, Kyoung-Dong Kim1, Seung-Hee Park1, Yong-Seop Byeon,
Seung-Beom Lim, and Jun-Young Lee

Abstract - An Uninterruptible Power Supply(UPS) is a system designed to deliver energy during accidents that the AC mains is out of its acceptable limits, without interruption of power flow through the load. Battery Discharger is the device to supply high quality power to the Inverter, when accidents occur, such as Power Failure. The Battery Discharger should have a fast response characteristics. The LLC resonant converter for UPS battery discharger is proposed. The proposed Battery Discharger offers substantial improvements in efficiency, size and cost. The proposed Battery Discharger of UPS approach is a good solution for high power applications above KW. To verify the validity of proposed Battery Discharger, simulations and experiments are carried out. Paper number: TKPE-2013-18-3-6 ISSN: 1229-2214 ✝ Corresponding author: pdpljy@mju.ac.kr, Dept. of Electrical Engineering, MyongJi University Tel: +82-31-330-6357 Fax: +82-31-330-6977 1 Dept. of Electrical Engineering, Myongji University 2 Eon Co., Ltd Manuscript received Oct. 5, 2012; accepted Feb. 20, 2013 ─ 본 논문은 2012년 전력전자학술대회 외부장학금 수혜논문임
DOWNLOAD
 http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=JRJJC3_2013_v18n3_240

https://www.mediafire.com/?143thdj9xfgg61s