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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Transactions of the Korean Institute of Power Electronics
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Journal DOI :
The Korean Institute of Power Electronics
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Volume & Issues
Volume 19, Issue 6 - Dec 2014
Volume 19, Issue 5 - Oct 2014
Volume 19, Issue 4 - Aug 2014
Volume 19, Issue 3 - Jun 2014
Volume 19, Issue 2 - Apr 2014
Volume 19, Issue 1 - Feb 2014
Selecting the target year
A Study on LED Driver Compatible with Triac-dimmer Employing Active Bleeder
Yeom, Bong-Ho ; Hong, Sung-Soo ; Kim, Taek-Woo ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 297~302
DOI : 10.6113/TKPE.2014.19.4.297
In this paper, a LED driver compatible with TRIAC-dimmer applying active bleeder is proposed. If TRIAC-dimmer is connected with LED driver, flicker phenomenon occurs by TRIAC malfunction. In order to prevent this problem, a current over holding current must flow into TRIAC. Therefore, additional circuit compatible with TRIAC-dimmer is required to provide enough current. Passive bleeder has power loss in whole operation period. The proposed circuit apply a valley-fill circuit for power-factor-correction and a novel active bleeder detecting malfunction point of TRIAC. Therefore, it prevent malfunction of TRIAC-dimmer and have advantage of higher efficiency than passive bleeder. To verify the validity of proposed circuit, 13W-lighting LED driver prototype has been proposed.
The Application and Verification of the 2MVA Battery Energy Storage System(BESS) with Wind-turbine in Micro-grid of Gapado, Jeju
Kim, Seung-Mo ; Oh, Seung-Jin ; Lee, Jong-Hak ; Kim, Tae-Hyeong ; Kwon, Byung-Ki ; Ahn, Jae-Min ; Jin, Kyung-Min ; Choi, Chang-Ho ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 303~311
DOI : 10.6113/TKPE.2014.19.4.303
This paper shows the test result of 2MVA BESS(Battery Energy Storage System) with wind-turbine in micro-grid of the Gapado. To implement of micro-grid with BESS, characteristics of generator and customer load in grid are considered. Also, to operate of 2-parallel PCU(Power Conversion Unit) in BESS, the droop control is adopted with operating mode of grid independent. Performances of BESS with wind-turbine were verified by analysis of power quality such as voltage harmonics, ratio of voltage and frequency regulation, and by measurement of waveform such as output voltage and current.
A Hybrid Anti-islanding Detection Scheme for Utility Interactive Inverter with Enhanced Harmonic Extraction Capability
Kang, Sung-Wook ; Kim, Kyeong-Hwa ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 312~319
DOI : 10.6113/TKPE.2014.19.4.312
When distributed generation such as a wind power system is connected to the grid, it should meet grid requirements like IEEE Std. 1547, which regulates the anti-islanding method. Since the islanding may cause damage on electrical equipments or safety hazards for utility line worker, a distributed generation should detect it as soon as possible. This paper proposes a hybrid anti-islanding method coupled with the active and passive detection methods. To enhance the harmonic extraction capability for an active harmonic injection method, cascaded second-order band-pass filter and signal processing scheme are employed. Simulation and experiments are carried out under the islanding test condition specified in IEEE Std. 1547. Passive over/under voltage and over/under frequency methods are combined with the active method to improve the detection speed under certain condition. The simulation and experimental results are presented to verify that the proposed hybrid anti-islanding method can effectively detect the islanding.
Smart Dimming Control Algorithm for Reducing Power Consumption of LED TV Backlight
Ryu, Je-Seung ; Park, Ju-Hee ; Lim, Seong-Ho ; Kim, Tae-Woo ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 320~326
DOI : 10.6113/TKPE.2014.19.4.320
In this paper, the new smart dimming algorithm which is mixed with PWM and PAM control method is proposed for reducing the power consumption of LED TV Backlight. The proposed technique is using the curve characteristics of LED forward voltage and current which is proportionally changing LED forward voltage as changing LED forward current. Therefore, each PWM and PAM control method has different LED forward voltage and current in the same brightness condition. The PWM control method adjusts the brightness of LED TV Backlight by only varying the duty ratio of PWM and constantly sustaining the amplitude of LED forward current and voltage. So, the level of LED forward current and voltage in the PWM control method is relatively high and constant regardless of duty ratio of PWM. On the other hand, the PAM control method adjusts the brightness of LED TV Backlight by directly varying the level of LED forward current. So, the level of LED forward current and voltage in the PAM control method is lowered according to the brightness level. For the above-mentioned reason, the PAM control method has the advantage of reducing the total power consumption of LED TV Backlight at the brightness condition of below 100%, compared with PWM control method. By implementing this characteristic to LED driver circuit with control algorithm in MCU, the power consumption of LED TV Backlight can expect to be reduced. The effectiveness of the proposed method, new smart dimming algorithm, CPWAM(=Conditional Pulse Width Amplitude Modulation), has been verified by experimental results.
A Study on Flicker Free LED Driver for Dimming MR16 Electronic Transformer
Kim, Taek-Woo ; Hong, Sung-Soo ; Yeom, Bong-Ho ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 327~331
DOI : 10.6113/TKPE.2014.19.4.327
LED(Light Emitting Diode) is a semiconductor device utilizing electroluminescent effect is a phenomenon in which a type of P-N junction diode, the light of short wavelength which a voltage is applied in the forward direction is released. LED is advantageous in reducing the energy as environmentally materials that can greatly reduce the carbon emissions, recent it has attracted attention IT(Information Technology) and GT(Green Technology) industry. In addition, there are advantages long life, high efficiency, and excellent response speed, LED have come into the spotlight as the illumination means to replace the existing fluorescent light and incandescent light bulb. When connecting to MR16 electronic transformer for existing LED driver circuit, due to malfunction of the dimmer and the electronic transformer, flicker occurs and linear dimming is not possible. Therefore, in this paper, we suggest an LED drive circuit there is no flicker with the corresponding dimming MR16 electronic transformer. Further, we explain the principles of the LED current control technique and the principle of the drive circuit of the LED, in order to validate the proposed circuit through prototyping and simulation.
Control of DC-side Voltage Unbalance among Phases in Multi-level H-Bridge STATCOM with Unbalanced Load
Kwon, Byung-Ki ; Jung, Seung-Ki ; Kim, Tae-Hyeong ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 332~341
DOI : 10.6113/TKPE.2014.19.4.332
A cascaded H-bridge multi-level STATCOM(STATic synchronous COMpensator), which is composed of many cell inverters with independent dc-sources, generates inevitably dc-side voltage unbalance among phases when it compensates unbalanced load. It comes from the difference of flowing active power in each phase when this compensator makes negative-sequence current to eliminate the unbalance of source-side current. However, this unbalance can be controlled by injecting zero-sequence current which is decoupled with grid currents, so the compensator can work well during this balancing process. Both a feedback control algorithm, which produces zero-sequence current proportional to dc-side voltage unbalance within each phase, and a feedforward control algorithm, which makes zero-sequence current directly from the compensator's negative-sequence current, were proposed. The dc-side voltage of each phase can be controlled stably by these proposed algorithms in both steady-state and transient, so the compensator can have fast response to satisfy control performance under rapid changing load. These balancing controllers were implemented and verified via simulation and experiment.
Sensorless BLDC Motor Control to Drive Fins for Flight Attitude Control of a Guided Artillery Munition
Lee, Tae-Hyung ; Kim, Sang-Hoon ; Cho, Chang-Yeon ; Pak, Chang-Ho ; Kim, Jae-Ho ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 342~348
DOI : 10.6113/TKPE.2014.19.4.342
In this paper, a BLDC(Brushless DC) motor control system for driving fins to control the flight attitude of the guided artillery munition is developed. This system adopts a sensorless control scheme without any position sensor such as a Hall sensor fragile at high altitudes. The sensorless control of the BLDC motor is achieved by using commutation signals obtained from the measured pole voltages. The position control of the fin is also performed by using of the estimated speed from the commutation signals. The experimental results on the actual fin drive system demonstrated that the developed sensorless control algorithm can give an excellent position control performance.
Analysis and Design of Continuous Current Mode Tapped-Inductor Boost Converter
Kang, Jeong-Il ; Han, Sang-Kyoo ; Han, Jonghee ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 349~356
DOI : 10.6113/TKPE.2014.19.4.349
As the turns ratio of the tapped-inductor contributes to the step-up ratio, the tapped-inductor boost (TIB) converter has significantly increased level of difficulties in its analysis and design compared to the conventional boost converter where the duty ratio is the sole factor affecting the step-up ratio. In this paper, the operation of the continuous current mode TIB converter is briefly reviewed, the characteristics are analyzed in detail, and a design guideline optimizing the loss in the tapped-inductor is presented with a practical design example. Finally, experimental results from a 12V/120V prototype for 0.25A LED driver application are also presented to confirm the design.
Programmable Smart Charger Compatible to Various Load Conditions
Jo, Kang-Ta ; Keum, Moon-Hwan ; Han, Sang-Kyoo ; Oh, Dong-Sung ; Sakong, Suk-Chin ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 357~363
DOI : 10.6113/TKPE.2014.19.4.357
A programmable smart charger compatible to various load conditions is proposed in this paper. Since the proposed smart charger is compatible to various mobile devices having different rated voltage and power, it is convenient for carrying and easy to standardize many kinds of battery chargers. Moreover, since it uses the input impedance and built-in PMIC (Power management IC) of the load system to recognize the connection state and specifications of load system, hardware changes of load system is not only hardly necessary but it also features no addition communication cable and easy implementation. To confirm the validity of the proposed charger, the theoretical analysis and experiment results from a prototype compatible to three load conditions 5V/1A, 5V/2A and 12V/1A are provided.
Design of High Efficiency Power Amplifier for Parametric Array Transducer using Variable Output Voltage AC/DC Converter
Shim, Jae-Hyeok ; Lee, Chang-Yeol ; Kim, Seul-Gi ; Kim, In-Dong ; Moon, Won-Kyu ; Lee, Jong-Hyeon ; Kim, Won-Ho ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 364~375
DOI : 10.6113/TKPE.2014.19.4.364
Parametric array transducers are used for long-range and highly directional communication in an underwater environments. The power amplifiers for parametric array transducers should have sufficient linear output characteristic and high efficiency to avoid communication errors, system heating, and fuel problems. But the conventional power amplifier with fixed source voltage is very low efficient due to large power loss by the big difference between the fixed source voltage and the amplifier output voltage. Thus to solve the problems this paper proposes the high efficiency power amplifier for parametric array transducers. The proposed power amplifier ensures high linearity of output characteristic by utilizing the push-pull class B type amplifier and furthermore gets high efficiency by applying the envelope tracking technique that variable source voltage tracks the envelope of the amplified signal. Also the paper suggests the detailed circuit topology and design guideline of class B push-pull type amplifier and variable output voltage AC/DC converter. Its characteristics are verified by the detailed simulation and experimental results.
A PWM Control Strategy for Low-speed Operation of Three-level NPC Inverter based on Bootstrap Gate Drive Circuit
Jung, Jun-Hyung ; Ku, Hyun-Keun ; Im, Won-Sang ; Kim, Wook ; Kim, Jang-Mok ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 376~382
DOI : 10.6113/TKPE.2014.19.4.376
This paper proposes the pulse width modulation (PWM) control strategy for low-speed operation in the three-level neutral-point-clamped (NPC) inverters based on the bootstrap gate drive circuit. As a purpose of the cost reduction, several papers have paid attention to the bootstrap circuit applied to the three-level NPC inverter. However, the bootstrap gate driver IC cannot generate the gate signal to the IGBT for low-speed operation, because the bootstrap capacitor voltage decreases under the threshold level. For low-speed operation, the dipolar and partial-dipolar modulations can be the effective solution. However, these modulations have drawbacks in terms of the switching loss and THD. Therefore, this paper proposes the PWM control strategy to operate the inverter at low-speed and to minimize the switching loss and harmonics. The experimental results are presented to verify the validity on the proposed method.
New Soft-Switching Method of 3-phase Interleaved Bidirectional DC-DC Converter for Battery Charging and Discharging
Jung, Jae-Hun ; Seo, Bo-Gil ; Kwon, Chang-Keun ; Nho, Eui-Cheol ; Kim, In-Dong ; Kim, Heung-Geun ; Chun, Tae-Won ;
The Transactions of the Korean Institute of Power Electronics, volume 19, issue 4, 2014, Pages 383~390
DOI : 10.6113/TKPE.2014.19.4.383
This paper deals with novel soft-switching method for a bidirectional DC-DC converter in battery charging and discharging system. The proposed soft-switching method provides ZVS and ZCS at turn-on, and ZVS at turn-off of the switch in both charging and discharging operation modes. The soft switching condition can be obtained in wide load range, and provide low switching loss as well as low voltage spike at turn-off of the switch. Proposed method is analyzed in charging and discharging mode. Simulation and experimental results validate the usefulness of the proposed soft-switching method.