A Controller Design for a Stability Improvement of an On-Board Battery Charger Hae-Gwang Jeong* and Kyo-Beum Lee†

A Controller Design for a Stability Improvement of an On-Board
Battery Charger
Hae-Gwang Jeong* and Kyo-Beum Lee†
Corresponding Author: Department of Electrical and Computer
Engineering, Ajou University, Suwon, Korea. (kyl@ajou.ac.kr)
* Dept. of Electrical and Computer Engineering, Ajou University,
Suwon, Korea. (lite88@ajou.ac.kr)
Received: May 27, 2013; Accepted: June 7, 2013

Abstract – This paper proposes the controller design for a stability improvement of an on-board
battery charger. The system is comprised of a power factor correction (PFC) circuit and phase shift
full-bridge DC-DC converter. The PFC circuit performs the control of the DC-link voltage and the
input power factor. The DC-DC converter regulates the voltage and the current in the battery using the
DC-link voltage. This paper proposes the design method of PI controller for the PFC circuit using a
small signal model. The analysis and design of a type-three controller for the DC-DC converter is also
presented. A simulation and experiment has been performed on the on-board battery charger and their
results are presented to verify the validity of the proposed system.
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http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=E1EEFQ_2013_v8n4_951

https://www.mediafire.com/?b466cwi2g7t404z

A Three-Phase High Frequency Semi-Controlled Battery Charging Power Converter for Plug-In Hybrid Electric Vehicles

A Three-Phase High Frequency Semi-Controlled
Battery Charging Power Converter for Plug-In
Hybrid Electric Vehicles
Mahmoud M. Amin and Osama A. Mohammed†
† Dept. of Electrical and Computer Eng., Florida International University, Florida, United States
Abstract
This paper presents a novel analysis, design, and implementation of a battery charging three-phase high frequency semicontrolled
power converter feasible for plug-in hybrid electric vehicles. The main advantages of the proposed topology include
high efficiency; due to lower power losses and reduced number of switching elements, high output power density realization, and
reduced passive component ratings proportionally to the frequency. Additional advantages also include grid economic utilization
by insuring unity power factor operation under different possible conditions and robustness since short-circuit through a leg is not
possible. A high but acceptable total harmonic distortion of the generator currents is introduced in the proposed topology which
can be viewed as a minor disadvantage when compared to traditional boost rectifiers. A hysteresis control algorithm is proposed
to achieve lower current harmonic distortion for the rectifier operation. The rectifier topology concept, the principle of operation,
and control scheme are presented. Additionally, a dc-dc converter is also employed in the rectifier-battery connection. Test results
on 50-kHz power converter system are presented and discussed to confirm the effectiveness of the proposed topology for PHEV
applications.
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http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=E1PWAX_2011_v11n4_490

A Study on the Hot Spot Temperature in 154kV Power Transformers Dong-Jin Kweon†, Kyo-Sun Koo*, Jung-Wook Woo* and Joo-Sik Kwak*

A Study on the Hot Spot Temperature in 154kV Power Transformers
Dong-Jin Kweon†, Kyo-Sun Koo*, Jung-Wook Woo* and Joo-Sik Kwak*
Abstract – The life of a power transformer is dependent on the life of the cellulose paper, which
influenced by the hot spot temperature. Thus, the determination of the cellulose paper’s life requires
identifying the hot spot temperature of the transformer. Currently, however, the power transformer
uses a heat run test is used in the factory test to measure top liquid temperature rise and average
winding temperature rise, which is specified in its specification. The hot spot temperature is calculated
by the winding resistance detected during the heat run test. This paper measures the hot spot
temperature in the single-phase, 154kV, 15/20MVA power transformer by the optical fiber sensors and
compares the value with the hot spot temperature calculated by the conventional heat run test in the
factory test. To measure the hot spot temperature, ten optical fiber sensors were installed on both the
high and low voltage winding; and the temperature distribution during the heat run test, three
thermocouples were installed. The hot spot temperature shown in the heat run test was 92.6℃ on the
low voltage winding. However, the hot spot temperature as measured by the optical fiber sensor
appeared between turn 2 and turn 3 on the upper side of the low voltage winding, recording 105.9℃.
The hot spot temperature of the low voltage winding as measured by the optical fiber sensor was 13.3℃
higher than the hot spot temperature calculated by the heat run test. Therefore, the hot spot factor (H)
in IEC 60076-2 appeared to be 2.0.
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http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=E1EEFQ_2012_v7n3_312

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Implementation of a High Efficiency Grid-Tied Multi-Level Photovoltaic Power Conditioning System Using Phase Shifted H-Bridge Modules

Implementation of a High Efficiency Grid-Tied
Multi-Level Photovoltaic Power Conditioning
System Using Phase Shifted H-Bridge Modules
Jong-Pil Lee†, Byung-Duk Min**, and Dong-Wook Yoo*
†*Power Conversion Research Center, Korea Electrotechnology Research Institute, Changwon, Korea
**Green Power Co. Ltd, Suwon, Korea
Abstract
This paper proposes a high efficiency three-phase cascaded phase shifted H-bridge multi-level inverter without DC/DC
converters for grid-tied multi string photovoltaic (PV) applications. The cascaded H-bridge topology is suitable for PV
applications since each PV module can act as a separate DC source for each cascaded H-bridge module. The proposed phase
shifted H-bridge multi-level topology offers advantages such as operation at a lower switching frequency and a lower current
ripple when compared to conventional two level topologies. It is also shown that low ripple sinusoidal current waveforms are
generated with a unity power factor. The control algorithm permits the independent control of each DC link voltage with a
maximum power point for each string of PV modules. The use of the controller area network (CAN) communication protocol for
H-bridge multi-level inverters, along with localized PWM generation and PV voltage regulation are implemented. It is also
shown that the expansion and modularization capabilities of the H-bridge modules are improved since the individual inverter
modules operate more independently. The proposed topology is implemented for a three phase 240kW multi-level PV power
conditioning system (PCS) which has 40kW H-bridge modules. The experimental results show that the proposed topology has good performance.
LINKS DOWNLOAD
http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=E1PWAX_2013_v13n2_296

Transformerless three-phase on-line UPS with high performance

Transformerless three-phase on-line UPS with
high performance
E.-H. Kim J.-M. Kwon B.-H. Kwon
Department of Electronic and Electrical Engineering, Pohang University of Science and Tech, Republic of Korea
E-mail: znight@postech.ac.kr
Abstract: A transformerless three-phase on-line uninterruptible power supply (UPS) is proposed. The proposed
UPS is composed of a rectifier, an inverter and a battery charger/discharger. The rectifier regulates a DC-link
voltage and performs power factor correction. On the other hand, the inverter provides a regulated sinusoidal
output voltage and has the current-limiting capability for an impulsive load. The battery charger/discharger
reduces the number of battery and supplies the power demanded by the load in the event of the input
power failure or abrupt decrease of the input voltage. Since both neutral lines of the input and output
voltages are connected at the centre of the DC-link, the need for an isolation transformer is eliminated and
the size, weight and cost of the system are significantly reduced. Additionally, new control algorithms of the rectifier, the charger/discharger and the inverter are proposed.
LINK
http://www.mediafire.com/view/7yl5uqoj5e3eq4s/TRANSFORMERLESS-UPS.pdf