• Journal of IKEEE
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• v.18 no.2
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• pp.220-227
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• 2014

This paper presents a control method of Single-Inductor Dual-Output DC-DC Converter using Common mode feedback and differential feedback loops. To generate duty used for differential mode feedback loop, this paper propose relative sawtooth circuit using current divider circuit which makes ramp signal with variable dead-time. Two outputs of the Single-Inductor Dual-Output DC-DC Converter are specified for 2.8 V and 4.2 V with input voltage 2.5 V. The maximum conversion efficiency of designed SIDO DC-DC Converter is 95% at total output power of 539mW. Cross regulations of Boost1 and Boost2 are 3.57% and 4% each, when increasing twice times output current.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.161-163
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• 2009

본 논문은 차세대 에너지 저장장치로 각광받는 슈퍼커패시터를 이용한 양방향 DC-DC컨버터의 구성 및 빠른 동특성을 갖는 이중 루프 PI제어기 설계를 제시하였다. 제어기는 초기 슈퍼캐패시터의 충전을 위한 정전류 제어기와 초기 충전 이후에 동작을 개시하는 전력제어기를 구성하였다. 구성된 제어기는 PSIM을 이용한 시뮬레이션을 통하여 검증하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.9
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• pp.1462-1469
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• 1997

This study presents a genetic algorithm-based method for optimizing control parameters in fluid power systems. Genetic algorithms are general-purpose optimization methods based on natural evolution and genetics. A genetic algorithm seeks control parameters maximizing a measure that evaluates system performance. Five control gains of the PID-PD cascade controller fr an electrohydraulic speed control system with a variable displacement hydraulic motor are optimized using a genetic algorithm in the experiment. Optimized gains are confirmed by inspecting the fitness distribution which represents system performance in gain spaces. It is shown that optimization of the five gains by manual tuning should be a task of great difficulty and that a genetic algorithm is an efficient scheme giving economy of time and in labor in optimizing control parameters of fluid power systems.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.475-476
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• 2010

본 논문은 에너지 저장장치로 각광받는 Li 배터리를 이용한 양방향 DC-DC컨버터의 구성 및 빠른 통특성을 갖는 이중 루프 PI제어기 설계를 제시하였다. 제어기는 초기 충전을 위한 정전류 제어기와 초기 충전 이후에 동작을 개시하는 전력제어기를 구성하였다. 배터리 모델링 및 양방향 DC-DC 컨버터용 제어기는 PSIM을 이용한 시뮬레이션을 통하여 검증하였으며, 그 타당성을 실험을 통하여 확인하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.34-44
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• 2007

Many urban cities deployed ITS technologies to improve the efficiency of traffic operation and management including a real-time franc control system (i.e., COSMOS). The system adopted loop detector system to collect traffic information such as volume, occupancy time, degree of saturation, and queue length. This paper investigated the applicability of detector information within COSMOS to represent the congestion level of the links. Initially, link travel times obtained from the field study were related with each of detector information. Results showed that queue length was highly correlated with link travel time, and direct link travel time estimation using the spot speed data produced high estimation error rates. From this analysis, a procedure was proposed to estimate congestion level of the links using both degree of saturation and queue length information.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.6
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• pp.524-530
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• 2002

A control of the body posture and movement is maintained by the vestibular system, vision, and proprioceptors. Afferent signals from those receptors are transmitted to the vestibular nuclear complex, and the efferent signals from the vestibular nuclear complex control the eye movement and skeletal muscle contract. The postural disturbance caused by loss of the vestibular function results in nausea, vomiting, vertigo and loss of craving for life. The purpose of this study is to develop a off-vertical rotatory system for evaluating the function of semicircular canals and otolith organs, selectively, and visual stimulation system for- stimulation with horizontal, vortical and 3D patterns. The Off-vortical axis rotator is composed of a comportable chair, a DC servo-motor with reducer and a tilting table controlled by PMSM. And a double feedback loop system containing a velocity feedback loop and a position feedback loop is applied to the servo controlled rotatory chair system. Horizontal, vertical, and 3D patterns of the visual stimulation for applying head mounted display are developed. And wireless portable systems for optokinetic stimulation and recording system of the eye movement is also constructed. The gain, phase, and symmetry is obtained from analysis of the eye movement induced by vestibular and visual stimulation. Detailed data were described.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.175-178
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• 1991

The drive system of servo motor is requested to have robustness of disturbance and parameter variation. However, the dynamics of PMSM drive change significantly by forced disturbance and parameter variation. Moreover, the state error caused by them should be suppressed completely and rapidly. In this paper, the vector-control system of PMSM using dual adaptive control loop is investigated. In the proposed system, linear adaptive control loop rapidly recovers the state error caused by both disturbance and parameter variation. In the dual adaptive control loop, the inner loop reduces the system sensitivity of parameter variation and disturbance, and the outer loop suppresses the state error caused by them completely. The proposed servo system is verified through a computer simulations and experimental results.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.528-529
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• 2012

연료전지는 매우 늦은 응답속도를 가지므로 부하 증가시 Li-Ion 배터리나 슈퍼 커패시터 같은 별도의 에너지 저장장치로부터 필요한 전류를 공급받도록 구성되는데 이들 사이에서 전력전달을 위해 DC-DC 컨버터가 필수적으로 요구된다. 본 논문에서는 상태평균화 기법과 PWM 스위치 모델을 사용하여 DC-DC 컨버터를 해석하고 시뮬레이션 하였다. 또한 배터리 등가회로를 구성해서 배터리 등가 임피던스를 고려한 이중루프 제어기를 설계하고 정전류/정전압 충전모드 시뮬레이션을 통해 효과를 확인하였다.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.48-55
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• 2004

This study presents a genetic algorithm-based method fur optimizing control parameters in the pressure control of electro-hydraulic pump with variable displacement. Genetic algorithms are general-purpose optimization methods based on natural evolution and genetics and search the optimal control parameters maximizing a measure that evaluates the performance of a system. Four control gains of the PI-PD cascade controller for an electro-hydraulic pressure control system are optimized using a genetic algorithm in the experiment. Optimized gains are confirmed by inspecting the fitness distribution which represents system performance in gain spaces. It is shown that genetic algorithm is an efficient scheme in optimizing control parameters of the pressure control of electro-hydraulic pump with variable displacement.

• New & Renewable Energy
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• v.20 no.2
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• pp.55-64
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• 2024

To ensure the frequency stability of wind power generation, we analyzedd the existing technology and proposedd a method for changing the gain value with respect to to the rotor speed by adding the MPPT reference value and output reference value that reflect the system frequency. The MPPT control and output were compared and calculated for performance verification. Subsequently, the application of the proposed algorithm led to an increased output when compared with that of the existing control method.