• 한국정보전자통신기술학회논문지
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• 제13권5호
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• pp.359-369
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• 2020

본 논문에서는 CMOS X-Ray 검출기의 메인 클럭을 발생시키는 위상 고정 루프(phase locked loop, PLL)을 위한 전류 불일치를 줄이면서도 넓은 동작 범위를 가지는 전하 펌프(charge pump, CP) 회로를 제안하였다. CP 회로의 동작 범위와 전류 불일치는 CP 회로를 구성하는 전류원 회로의 동작 범위와 출력 저항에 의해서 결정된다. 제안된 CP 회로는 넓은 동작 범위를 확보하기 위한 wide operating 전류 복사 바이어스 회로와 전류 불일치를 줄이기 위한 출력 저항이 큰 캐스코드 구조의 전류원으로 구현하였다. 제안된 wide operating range 캐스코드 CP 회로는 350nm CMOS 공정을 이용하여 칩으로 제작되었으며 소스 측정 장치(source measurement unit)을 활용하여 전류 일치 특성을 측정하였다. 이때 전원 전압은 3.3V이고 CP 회로의 전류 ICP=100㎂이었다. 제안된 CP 회로의 동작 범위 △VO_Swing=2.7V이고 이때 최대 전류 불일치는 5.15%이고 최대 전류 편차는 2.64%로 측정되었다. 제안된 CP 회로는 낮은 전류 불일치 특성을 가지면서 광대역 주파수 범위에 대응할 수 있으므로 다양한 클럭 속도가 필요한 시스템에 적용할 수 있다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권4호
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• pp.280-285
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• 2004

In this paper, a 9-bit analog-to-digital converter (ADC) is designed for optical disk drive (ODD) servo applications. In the ADC, the circuit technique to increase the operating range of the sample-and-hold amplifier is proposed, which can process the wide-varying input common-mode range. The algorithmic ADC structure is chosen so that the area can be significantly reduced, which is suitable for SoC integration. The ADC is fabricated in a 0.18-$\mu\textrm{m} $ CMOS 1P5M technology. Measurement results of the ADC show that SNDR is 51.5dB for the sampling rate of 6.5MS/s. The power dissipation is 36.3mW for a single supply voltage of 3.3V.

• Journal of Power Electronics
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• 제9권5호
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• pp.772-780
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• 2009

A novel soft-switching two-switch flyback converter is proposed in this paper. This converter is composed of two active power switches, a flyback transformer, a blocking diode, and two passive regenerative clamping circuits. The proposed converter has the advantages of a low cost circuit configuration, a simple control scheme, a high efficiency, and a wide operating range. The circuit topology, analysis, design considerations, and experimental results of the new flyback converter are presented.

• Journal of Power Electronics
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• 제12권6호
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• pp.851-858
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• 2012

This paper presents resonant inverter tuning for current source parallel resonant induction heating systems based on a new self oscillating switching technique. The phase error is suppressed in a wide range of operating frequencies in comparison with Phase Locked Loop (PLL) techniques. The proposed switching method has the capability of tuning under fast changes in the resonant frequency. According to this switching method, a multi-frequency induction heating (IH) system is proposed by using a single inverter. In comparison with multi-level inverter based IH systems, the advantages of this technique are its simple structure, better transients and wide range of operating frequencies. A laboratory prototype was built with an operating frequency of 35 kHz to 55 kHz and 300 W of output power. The performance of the IH system shows the validity of the new switching technique.

• 전력전자학회논문지
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• 제24권4호
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• pp.294-302
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• 2019

A capacitor common connected LLC resonant converter with auxiliary switches for a wide output voltage control range is presented in this paper. The proposed converter can be controlled in two ways to achieve a wide output voltage control range of Vo-3Vo. The first control method is performed through pulse width modulation of the auxiliary switches and primary switching devices. The second control method is conducted through frequency modulation of the primary switching devices configured to operate in full-bridge switching modes, when the auxiliary switches are turned off. The feasibility of the proposed converter is verified by the experimental results of a 5 kW prototype.

• Smart Structures and Systems
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• 제19권5호
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• pp.567-576
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• 2017

Design of piezoelectric energy harvester for a wide operating frequency range is a challenging problem and is currently being investigated by many researchers. Widening the operating frequency is required, as the energy is harvested from ambient source of vibration which consists of spectrum of frequency. This paper presents a new technique to increase the operating frequency range which is achieved by designing a harvester featured by a propped cantilever beam with variable over hang length. The proposed piezoelectric energy harvester is modeled analytically using Euler Bernoulli beam theory and the effectiveness of the harvester is demonstrated through experimentation. The results from analytical model and from experimentation reveal that the proposed energy harvester generates an open circuit output voltage ranging from 36.43 V to 11.94 V for the frequency range of 27.24 Hz to 48.47 Hz. The proposed harvester produces continuously varying output voltage and power in the broadened operating frequency range.

• 전기학회논문지
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• 제58권1호
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• pp.69-76
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• 2009

This paper describes sensorless high-speed control for 45,000rpm/22kw type PMSM by using iterative adaptive sliding mode observer. The proposed algorithm is based on sensorless vector control by on-line estimating the speed of rotor in the wide speed operating range between the starting operation. In addition, it shows the enhanced performance of the iterative adaptive observer by lessening its chattering and getting stable response in limited PWM period. The simulation and experiment results show the reliable performance of the proposed algorithm through starting to high speed operating range.

• 전산구조공학
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• 제27권1호
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• pp.26-33
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• 2014

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.665-673
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• 2017

This paper proposes a field weakening control method for operating an induction motor with a variable DC input voltage condition. In the variable DC voltage condition such as a battery, the field weakening method are required for the maximum output power. The conventional field weakening control methods can be used for operating the induction motor over the rated speed in a constant DC-link voltage condition. However, the conventional methods for operating the motor with the variable DC voltage is not suitable for the maximum output power. To overcome this problem, this paper proposes the optimized field weakening control method to extend the operating range of the induction motor with a rated power in a limited thermal and a wide DC input voltage conditions. The optimized d-axis and q-axis current equations are derived according to the field weakening region I and II to extend the operating region. The experimental results are presented to verify the effectiveness of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.183-186
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• 2002

The paper is proposed intantaneous torque control of IPMSM for drive of wide speed range. The control scheme is based on the mathematical model of the motor and is applicable to the constant torque and field weakening operations The scheme allows the motor to be driven with maximum torque per ampere (MTPA) characteristic below base speed and it maintains the maximum voltage limit of the motor wide field weakening and the motor current limit under all conditions of operation accurately. For each control mode. a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. The proposed control algorithm is applied to PMSM drive system for drive of wide speed range, the operating characteristics controlled by maximum torque control are examined in detail by simulation.