• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.353-356
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• 1997

Vehicle steering system determines the direction of a vehicle. A manual steering system consists of mechanical connections between the steering wheel and tires. Recent power steering system adds an actuator to help a driver to steer easily at low speed. However, at front collision, the driver can be injured by steering shaft and the power steering pump decreases the engine power. To solve these problems, electronic power steering system which connects the steering wheel and tires with electronic connection is proposed, that has advantages such as decrease of engine load and increase of driver safety reactive. Since the ratio between driver's steering torque and steering torque of tires can be controlled freely, the torque which is delivered from the road to the driver through tires and steering wheel can be reshaped to make the driver feel comfortable. In this paper, the ratio of delivering steering torque and the magnitude of force to be delivered from road to driver has been controlled using fuzzy controller, and it's effectiveness has been shown through simulation results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.50-51
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• 2009

This paper presents integrated passive device (IPD) based on Wilkinson power divider. The simulated 2-way power divider has the insertion loss of 3.123 dB, output isolation of -24.576 dB, input return loss of 26.415 dB, and output return loss of 33.478 dB. The power divider is based on IPD process design simulation at 2.5 GHz for WiMAX (Worldwide Interoperability for Microwave Access) applications. The chip size of power divider is $1\;\times\;1.2\;mm^2$, which is under fabrication.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.130-131
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• 2013

In this paper, it suggests offset compensation method of output current in single phase PV-BES system which is connected with grid. The algorithm applied removes grid's frequency ingredient using a notch filter and it extracts only DC offset current. It can reduce problems as saturation of power transformer cause by DC current when it is indoctrinated to grid.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.93-94
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• 2014

Recently, According to increase of power demand, it was increased a demand that switching power supply have characteristic of low-loss and high-efficiency. So increase of using device, the failure rate increases and service life problem arises. Even though normal circuit protection is applied in designing stage, it is often hard to identify the cause of malfunction in certain cases such as fatigued power supply due to over-running, malfunctions of main elements or over heating. This report will cover experimental results with the prototype we made, that monitors the efficiency of switching power supply and that protects a circuit when it drops below the standard value.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.235-236
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• 2015

본 논문에서는 universal line 입력 및 전 부하영역에서 영전압 스위칭(Zero Voltage Switching) 보장을 통한 500kHz 고 주파수 구동의 Dual Mode control LLC 컨버터를 제안한다. 제안 회로는 전 부하영역에서의 ZVS(영전압 스위칭)보장으로 고주파 구동이 가능하여 전원회로의 부피 중 상당량을 차지하는 수동소자의 부피를 대폭 저감 할 수 있다. 또한, 소용량 전원회로는 PFC(Power Factor Correction)의 규제가 없기 때문에 universal line 입력에 대응이 가능해야하므로, 제안회로는 변화하는 입력전압과 출력전류에 따라 PFM과 PWM의 두 가지 모드로 동작하여 universal line 입력 및 전 부하 영역에서 정확한 출력전압 제어가 가능하다. 최종적으로 제안 회로의 타당성 검증을 위하여 60W급 adapter의 전원회로를 위한 시작품을 제작하여 고찰된 실험 결과를 제시한다.

• 전기전자학회논문지
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• 제23권1호
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• pp.127-133
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• 2019

미래에 스마트 그리드 도입을 위해 전력수요예측은 중요한 연구 분야 중 하나이다. 하지만 전력데이터는 많은 외부적 요소들에 영향을 받기 때문에 예측하기 어렵다. 기존의 전력수요예측 방법들은 가공되지 않은 전력데이터를 그대로 이용하기 때문에 정확도 높은 예측을 하는데 한계가 있어왔다. 본 논문에서는 가공되지 않은 전력데이터를 이용하는 전력수요예측의 문제를 해결하기 위해 확률기반 학습알고리즘을 제안한다. 확률 모델은 전력데이터의 확률적 특성을 분석하기에 적합하다. 제안한 모델의 중기 전력수요예측 성능을 비교하기 위해 신경망 네트워크 중 하나인 순환신경망과 성능 비교를 해보았다. 매사추세츠 대학에서 제공한 전력데이터를 이용하여 성능 비교를 한 결과 본 논문에서 제안한 확률기반 학습알고리즘이 중기 수요예측에 더 좋은 성능을 나타냄을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.255-258
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• 1996

This paper describes a DC voltage controller for the DC power supply which is constructed using the full-bridged MOS-FET DC-to-RF power inverter and rectifier. The full-bridged MOS-FET DC-to-RF inverter consisting of four MOSFET arrays and an output power transformer has a control function which is able to control the RF output power when the widths of the pulse voltages which are fed to four MOS-FET arrays of the fall-bridged inverter are changed using the pulse width control circuit. The power conversion efficiency of the full-bridged MOS-FET DC-to-RF power inverter was approximately 85 % when the duty cycles of the pulse voltages were changed from 30 % to 50 %. The RF output voltage from the full-bridged MOS-FET DC-to-RF inverter is fed to the rectifier circuit through the output transformer. The rectifier circuit consists of GaAs schottky diodes and filters, each of which is made of a coil and capacitors. The power conversion efficiency of the rectifier circuit was over 80 % when the duty cycles of the pulse voltages were changed from 30 % to 50 %. The output voltage of the rectifier circuit was changed from 34.7V to 37.6 V when the duty cycles of the pulse voltages were changed from 30 % to 50 %.

• ETRI Journal
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• 제30권3호
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• pp.347-354
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• 2008

In this paper, the design of a low-power 512-bit synchronous EEPROM for a passive UHF RFID tag chip is presented. We apply low-power schemes, such as dual power supply voltage (VDD=1.5 V and VDDP=2.5 V), clocked inverter sensing, voltage-up converter, I/O interface, and Dickson charge pump using Schottky diode. An EEPROM is fabricated with the 0.25 ${\mu}m$ EEPROM process. Power dissipation is 32.78 ${\mu}W$ in the read cycle and 78.05 ${\mu}W$ in the write cycle. The layout size is 449.3 ${\mu}m$ ${\times}$ 480.67 ${\mu}m$.

• 전력전자학회논문지
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• 제21권2호
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• pp.95-101
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• 2016

This paper proposed a high-power density bidirectional converter for hybrid electric vehicle high-voltage DC-DC converter(HDC). The conventional HDC has two disadvantages. First, large inductance is required to satisfy the ripple current of inductor by low switching frequency (<20 kHz). Second, large core size is required to prevent the saturation of inductor by high current. Compared with the conventional HDC, the proposed HDC can reduce inductance with SiC-FET for high frequency driving. High-power density of I/O capacitors can be achieved through two-phase interleaved method. The high-power density of inductors can be achieved because the offset current of magnetizing inductance is theoretically terminated by using the differential mode coupled inductor instead of using two single inductors. The validity of the proposed converter is proved through the 50 kW prototype.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.631-633
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• 2000

Modern consumer electronic products like TV, VCR etc, offer users the convience of switching the equipment on and off via a remote control handset. When this type of equipments is switched off, it is said to be in standby mode. In this paper, We proposed that the method of the blocking standby power Son in industrial product including electronic and electronic appliauces. This method is perfectly blocking the standby power of electrical circuit.