• 한국산학기술학회논문지
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• 제9권6호
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• pp.1585-1591
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• 2008

현재 움직이는 물체의 운동을 제어하기 위해 하중이라는 개념의 사용이 시도되고 있다. 하중이라는 제어 개념으로 불확실성으로 인한 비선형성을 포함한 시스템에서 신뢰성 있는 제어값을 찾기 위해 MIN 설계 방법이 제안되었다. 이러한 MIN설계 방법에서는 기존의 선형화 방법에 의한 상태방정식에서의 제어값을 찾는 문제와 달리 비선형하중 모델에서 직접 제어 값을 찾는 방식을 보이고 있다. 본 논문에서는 미사일 하중 운동역학과 유도 기하학의 비선형 역학을 고려한 하중 제어값을 찾는다. 즉 시선각 또는 미사일의 받음각 변화에 따른 진행방향에 대한 미사일의 속도 조건을 만족하기 위한 제어값과 표적을 따라가기 위한 선회 각도을 위한 제어값을 구한다. 즉 본 논문에서는 미사일 시스템과 추적 동역학에서 하중 제어값을 구해본다. 이렇게 구해진 하중 제어값으로 유도 제어 법칙을 비선형 시스템에서 직접 쉽게 구할 수 있음을 확인해 보았다.

• 전력전자학회논문지
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• 제3권2호
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• pp.99-106
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• 1998

This paper proposed a speed control system for induction motors robust to variations in torque and parameters by feedforward compensating the current portion of load torque, adding a load torque observer to the conventional PI controller in the indirect vector controlled induction motor system. Computer simulations and exeperimental works using the proposed control confirm that the transient response for the variation of the reference speed and load torque becomes improved, compared with the conventional PI controled method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.152-155
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• 1997

This thesis proposed a speed control system for induction motors robust to variations in torque and parameters by feedforward compensating the current portion of load torque, adding a load torque observer to the conventional PI controller in the indirect vector controlled induction motor system. In conclusion, this thesis demonstrate the improved transient characteristic to variations in reference speed and load torque, compared to the conventional PI control method, by means of the feedworward control of the estimated load torque.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.165-168
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• 1995

The recent rapid growth of air conditioning load has become a major reason of peak load increase in summer. In connection with this, we surveyed the load management projects of utilities world-wide and their detailed activities. This study is to develop a remote load control system using computer and radio communications. We finished the field-test of this system on August 1995 in Seoul area. During the field-test, the remote load control of air conditioners was proved to be well-timed. Two control modes, group control and all control, are available for the user to select. The transmission reliability of the load control signal was very good and the functions of system hardware as well as the software were excellent. So we confirmed the applicability of the load control system including the paper communication network. In this paper, detailed information on the system functions and experimental results are described.

• 전기학회논문지P
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• 제65권4호
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• pp.255-261
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• 2016

Korean Power System are operating a load shedding system to prevent voltage instability phenomenon caused by severe line contingencies. In order to apply the load shedding scheme should be selected a location, amount, delay time. Current load shedding system is load shedding amount that has been calculated in the steady-state analysis to load shed the total amount in first level, load shedding amount calculated in advance, it is possible to perform an unnecessary load shedding. In this paper, set a multi-level load shedding control strategy step-by-step selection of load shedding amount for the prevention of excessive load shedding. In addition, through a voltage resilience analysis of the power system by applying motor load ratio and sensitivity parameter to selection the multi level load shedding ratio and delay time. For this reason, to take advantage of the limit data of interchange power, by utilizing interface power flow data to set a multi-level load shedding control strategy for the stabilization of the Korean Power System.

• Journal of Mechanical Science and Technology
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• 제15권6호
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• pp.720-726
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• 2001

This paper describes a vehicle driving-load estimation method for application to vehicle Intelligent Cruise Control (ICC). Vehicle driving-load consists of aerodynamic force, rolling resistance, and gravitational force due to road slope and is unknown disturbance in a vehicle dynamic model. The vehicle driving-load has been estimated from engine and wheel speed measurements using a vehicle dynamic model a least square method. The estimated driving-load has been used in the adaptation of throttle/brake control law. The performance of the control law has been investigated via both simulation and vehicle tests. The simulation and test results show that the proposed control law can provide satisfactory vehicle-to-vehicle distance control performance for various driving situations.

• 유공압시스템학회논문집
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• 제6권3호
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• pp.16-22
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• 2009

This paper deals with the issue of robust position tracking control and energy-saving control for a valve-controlled cylinder system using speed-controlled fixed displacement pump. The whole feedback control system is composed of a pair of interconnected subsystems, that is, valve-controlled cylinder system and load-sensing control system. From experiments it is shown that position tracking control in the load sensing control system can accomplish significant reduction in input energy to pump comparing to a conventional valve-controlled cylinder system, while exhibiting the same position tracking control accuracy.

• 전기학회논문지
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• 제63권12호
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• pp.1627-1636
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• 2014

In real-time electricity price environment, the energy management system can provide the significant advantage to the residential, commercial and industrial customers since it can reduce the electricity charge by controlling the load operation effectively in response to time-varying price. However, the earlier studies for load management mainly focus on the residential and commercial customers except for the industrial customers because most of load operations in industrial sector are intimately related with production schedule. So, it is possible that the inappropriate control of loads in industrial sector causes huge economic loss. In this paper, therefore, we propose load control algorithm for factory energy management system(F-EMS) to achieve not only minimizing the electricity charges but also maintaining production efficiency by considering characteristics of load operation and production schedule. Considering characteristics of load operation and production schedule, the proposed load control algorithm can reflect the various characteristics of specific industrial customer and control their loads within the range that the production efficiency is maintained. Simulation results show that the proposed load control algorithm for F-EMS leads to significant reduction in the electricity charges and peak power in industrial sector.

• 전력전자학회논문지
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• 제22권6호
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• pp.527-534
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• 2017

This paper proposes a new DC link voltage controller for a single-phase power factor correction (PFC) boost converter. The load current of the PFC boost converter affects the capacitor current, whereas the load current changes the output voltage. However, previous works that compensate output current have failed to consider the relationship between load current and duty. Thus, they also fail to maintain a constant output voltage if the load fluctuates under the conditions of a non-rated input voltage. By considering the duty in the load current compensation, the proposed method improves the load transient response regardless of the input voltage. To demonstrate its effectiveness, the proposed method is compared with other control methods by conducting PSM simulations and experiments under a rapidly changing load.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.290-297
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• 2002

This paper presents analysis results for the effect of power control strategies on the part load performance of gas turbine based power generation systems utilizing exhaust heat of the gas turbine such as cumbined cycle power plants and regenerative gas turbines. For the combined cycle, part load efficiency variations were compared among different single shaft gas turbines representing various technology levels. Power control strategies considered were fuel only control and IGV control. It has been observed that gas turbines with higher design performances exhibit superior part load performances. Improvement of part load efficiency by adopting air flow modulation was analyzed and it is concluded that since the average combined cycle performance is affected by the range of IGV control as well as its temperature control principle, a control strategy appropriate for the load characteristics of the individual plant should be adopted. For the regenerative gas turbine, it is likewise concluded that maintaining exhaust temperature as high as possible by air flow rate modulation is required to increase part load efficiency.