• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1422-1424
• /
• 2005

본 논문에서는 전원회로의 박형화에 장애가 되는 자기소자(인덕터/변압기)를 박형의 자기코어와 PCB 권선을 이용하여 박형으로 설계/제작하고 이를 역률보상회로와 서스테인 전원회로로 구성된 AC-PDP 전원회로에 적용한다. 이러한 역률보상회로와 서스테인 전원회로로 구성된 AC-PDP 전원회로를 박형자기소자, 박형커패시터 SMD소자를 이용하여 두께 30mm이하로 설계/제작하여 AC-PDP TV 시스템의 박형화 가능성을 제시한다. 또한 입력전압 90-260$V_{rms}$의 범위에서 역률개선 여부를 검증하고, 서스테인 전원회로의 부하변동에 따른 전체 AC-PDP 전원회로의 효율을 측정, 검증한다. 전원회로 각각의 구성요소에서 발생하는 전력손실을 분석하여 안정적인 AC-PDP 전원회로의 설계 가능성을 제시한다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.6
• /
• pp.554-562
• /
• 2002

This paper presents a new sensorless control scheme using simple duty signal feedback technique in DC/DC converters. The proposed Duty Feedback Control(DFC) has the characteristics that they show the same as operation performance of current mode control by using duty feedback technique without current sensor as well as present faster dynamic response performance than conventional Sensorless Current Mode(SCM) control in case that input source is perturbed by step change or DC input source includes the harmonics. Also, the proposed control scheme has good noise immunity and simple control circuits since they have one feedback loop, and can be applied to all DC/DC converters. The concept and control principles of the proposed control scheme are explained in detail and the validity of the proposed control scheme is verified through several interesting simulated and experimental results.

• Journal of Digital Convergence
• /
• v.12 no.3
• /
• pp.243-248
• /
• 2014

Recently, solar energy is expanding to combination of computing in real time by tracking the position of the sun to estimate the angle of inclination and make up freshly correcting a part of the solar radiation. Solar power is need that reliably linked technology to power generation system renewable energy in order to efficient power production that is difficult to output predict based on the position of the sun rise. In this paper, we analysis of prediction model for solar power generation to estimate the predictive value of solar power generation in the development of real-time weather data. Photovoltaic power generation input the correction factor such as temperature, module characteristics by the solar generator module and the location of the local angle of inclination to analyze the predictive power generation algorithm for the prediction calculation to predict the final generation. In addition, the proposed model in real-time national weather service forecast for medium-term and real-time observations used as input data to perform the short-term prediction models.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.16 no.3
• /
• pp.209-218
• /
• 2011

In low voltage high current applications such as fuel cells the current-fed DC-DC converter which has small ripple current and turn ratio is more efficient. In the applications larger than 5kW the conventional single-phase current-fed converter based on full-bridge, half-bridge or push-pull topologies has high current burden of devices such as switches, and the selection and optimized design of the devices are not easy. In this paper a three-phase active-clamped current-fed push-pull DC-DC converter suitable for high power high step-up applications is proposed. The proposed converter has reduced current burden and is suitable for wide input voltage applications due to the use of whole duty cycle range. Design methods of main components including three-phase high frequency transformers are provided, and the validity and performance of the proposed converter are proved from a 5kW prototype.

• Journal of Digital Convergence
• /
• v.12 no.3
• /
• pp.211-218
• /
• 2014

Recently, wind energy is expanding to combination of computing to forecast of wind power generation as well as intelligent of wind powerturbine. Wind power is rise and fall depending on weather conditions and difficult to predict the output for efficient power production. Wind power is need to reliably linked technology in order to efficient power generation. In this paper, distributed power generation forecasts to enhance the predicted and actual power generation in order to minimize the difference between the power of distributed power short-term prediction model is designed. The proposed model for prediction of short-term combining the physical models and statistical models were produced in a physical model of the predicted value predicted by the lattice points within the branch prediction to extract the value of a physical model by applying the estimated value of a statistical model for estimating power generation final gas phase produces a predicted value. Also, the proposed model in real-time National Weather Service forecast for medium-term and real-time observations used as input data to perform the short-term prediction models.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.16 no.3
• /
• pp.242-249
• /
• 2011

The proposed converter has easy device selection for high step-up and high power applications since boost half bridge and voltage doubler cells are connected, respectively, in parallel and series in order to increase output power and voltage. Especially, optimized design of high frequency transformers is possible owing to reduced turn ratio and eliminated dc offset, and distributed power through three cores is beneficial to low profile and thermal distribution. The proposed converter does not necessitate start-up circuit and additional clamp circuit due to the use of whole duty range between 0 and 1 and is suitable for applications with wide input voltage range. Also, high efficiency can be achieved since ZVS turn on of switches are achieved in wide duty cycle range and ZCS turn on and off of diodes are achieved. The proposed converter was validated through 5 kW prototype.

• Nuclear Engineering and Technology
• /
• v.21 no.1
• /
• pp.18-31
• /
• 1989

To analyze the impact of air pollution control on electricity generation cost, a computer program was developed. POGEN calculates levelized discounted power generation cost including additional air pollution control cost for coal power plant. Pollution subprogram calculates total capital and variable costs using governing equations for flue gas control. The costs are used as additional input for levelized discounted power generation cost subprogram. Pollution output for Rue Gas Desulphurization direct cost was verified using published cost data of well experienced industrialized countries. The power generation costs for the year 2001 were estimated by POGEN for three different regulatory scenarios imposed on coal power plant, and by levelized discounted power generation cost subprogram for nuclear power. Because of uncertainty expected in input variables for future plants, sensitivity and uncertainty analysis were made to check the importance and uncertainty propagation of the input variables using Latin Hypercube Sampling and Multiple Least Square method. Most sensitive parameter for levelized discounted power generation cost is discount rate for both nuclear and coal. The control cost for flue gas alone reaches additional 9-11 mills/kWh with standard deviation less than 1.3 mills/kWh. This cost will be nearly 20% of power generation cost and 40% of one GW capacity coal power plant investment cost. With 90% confidence, the generation cost of nuclear power plant will be 32.6-51.9 mills/kWh, and for the coal power plant it will be 45.5-50.5 mills/kWh. Nuclear is favorable with 95% confidence under stringent future regulatory requirement in Korea.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.15 no.3
• /
• pp.421-432
• /
• 2020

This paper proposes a 2-kW solid-state power amplifier (SSPA) developed by employing power amplifier pallets designed using gallium-nitride high electron mobility transistors, which is used in S-band military radars and to replace existing traveling-wave tube amplifier (TWTA). The SSPA consists of a high-power amplifier module, which combines eight power amplifier pallets, a drive amplifier module, a digital control module, and a power supply unit. First, the amplifier module and component were integrated into a small package to account for space limitations; next, an on-board harmonic filter was fabricated to reject spurious components; and finally, an auto gain control system was designed for various duty ratios because recent military radar systems are all active phase radars using the pulse operation mode. The developed SSPA exhibited a max gain of 48 dB and an output power ranging between 63-63.6 dBm at a frequency band of 3.1 to 3.5 GHz. The auto gain control function showed that the output power is regulated around 63 dBm despite the fluctuation of the input power from 15-20 dBm. Finally, reliability of the developed system was verified through a temperature environment test for nine hours at high (55 ℃) / low (-40℃) temperature profile in accordance with military standard 810. The developed SSPA show better performance such as light weight, high output, high gain, various safety function, low repair cost and short repair time than existing TWTA.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.5 no.5
• /
• pp.419-426
• /
• 2000

Generally diode rectifier has been used as Preregulator of arc- welding machine. Its defect is the generation of high current harmonics which result In utility pollution. In this parer, using the three-phase PWM converter, the input performance of arc-welding machine is improved by increasing the input power factor. When the diode rectifier in the arc-welding machine is replaced with three-phase PWM converter, PWM converter should control DC voltage of the output side. If PI controller is used for the output DC voltage regulator, the output DC voltage has high ripple voltage due to the instantaneous load variation in the arc-welding machine. In this paper, the feedforward compensator has been introduced to reduce the DC voltage ripple. It lessens the influence of load current which is the disturbance of the output DC voltage regulator. Theoretical prediction of this analysis has been verified by comparing with experimental data

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.1
• /
• pp.84-87
• /
• 2016

In this paper, a receiver for wireless power transfer is proposed. The receiver consists of a 100 W rectifier in 1.8 MHz frequency band, and a constant current charger. In particular, two kinds of protection circuits are installed in the rectifier. They are a over-voltage protection circuit which block the input voltages greater than 30 V and a active-dummy load which maintains the receiver input impedance by automatically consuming the remaining input power. The constant current charger is designed to charge the battery with a charging current of up to 1 A. A wireless charging system is fabricated using the proposed receiver. The system is composed of a 130 W transmitter, two magnetic resonator, and proposed receiver for charging a 48 V Li-Ion battery using the coupled magnetic resonance method. By the measurement result, the system efficiency is about 54 %.