• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1658-1662
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• 2010

This paper presents an advanced energy saving algorithm in building. It is important to aggregate a various demand side resource which is surely controllable at the peak power time to reduce the energy cost. Previous demand side algorithm appropriate for building is based on peak power. In this paper, we develop the new energy saving algorithm to reduce the quantity of power consumption. The simulation results show that the proposed tem is very effective.

• Proceedings of the KIEE Conference
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• summer
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• pp.686-688
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• 2004

We suggest that the core factor which can be established successfully pushing ahead with domestic load management program is finding and keeping management of controllable load resources. We know that load management is mostly the maximum demand power management and participation of DLC program. This paper suggests the way coping with load management suggesting model which air conditioning and heating load facilities are applied to DU program.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2076-2078
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• 2002

This paper presents an Intelligent Balance Beam Controller(IBBC) which can estimate the inertia of load automatically. Balance Beam controller is a kind of construction tool which can control the attitude of the load hanging in the air such as a beam carried by crane. In our previous work, Balance Beam had been built to control the object in air using a mechanical gyro system having a position controllable gimbal structure. In field application the load inertia for operation is not easy to figure out because the weight and shape which determines the inertia, varies depending on the object to be carried. Therefore it is difficult for a worker to operate a Balance Beam and an accident could be caused occasionally. We designed an automatic load estimator to measure the inertia of arbitrary load by using an angular velocity sensor that is installed on the Balance Beam. Simulation results and current status for implementation are presented.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1061-1070
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• 2018

The main purpose of retaining wall methods for deep excavation is to keep the construction site safe from the earth pressure acting on the backfill during the construction period. Currently used retaining wall methods include the common strut method, anchor method, slurry wall method, and raker method. However, these methods have drawbacks such as reduced workspace and intrusion into private property, and thus, efforts are being made to improve them. The most advanced retaining wall method is the prestressed wale system, so far, in which a load corresponding to the earth pressure is applied to the wale by using the tension of a prestressed (PS) strand wire. This system affords advantages such as providing sufficient workspace by lengthening the strut interval and minimizing intrusion into private properties adjacent to the site. However, this system cannot control the tension of the PS strand wire, and thus, it cannot actively cope with changes in the earth pressure due to excavation. This study conducts a preliminary numerical analysis of the field applicability of the controllable prestressed wale system (CPWS) which can adjust the tension of the PS strand wire. For the analysis, back analysis was conducted through two-dimensional (2D) and three-dimensional (3D) numerical analyses based on the field measurement data of the typical strut method, and then, the field applicability of CPWS was examined by comparing the lateral deflection of the wall and adjacent ground surface settlements under the same conditions. In addition, the displacement and settlement of the wall were predicted through numerical analysis while the prestress force of CPWS was varied, and the structural stability was analysed through load tests on model specimens.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.419-424
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• 2011

The system-on-board detectable and controllable the electrical fires due to ground fault(GF), arc fault and overload is implemented. The system IC for controlling and preventing the electrical fires is available to this system. The GF detection circuit for detecting the electrical leakage current, the arc fault detection circuit and the overload detection circuit controllable the input voltage for flowing the overload current are designed. The GF detection circuit and the arc fault detection circuit are good operated to the electrical leakage current and the arc signal, respectively. It is confirmed that the overload detection circuit has shown no erratic operation with the noise or the load variation and is only operated at the overload condition.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.6
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• pp.424-432
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• 2018

This study presents a single-phase single-stage three-level AC/DC converter with a wide controllable output voltage. The proposed AC/DC converter is designed to extend the application of e-mobility, such as electric vehicles. The single-stage converter integrates a PFC converter and a three-level DC/DC converter, operates at a fixed frequency, and provides a wide controllable output voltage (approximately 200-430Vdc) with high efficiencies over a wide load range. In addition, the input boost inductors operate in a discontinuous mode to improve the input power factor. The switching devices operate with ZVS, and the converter's THD is small, especially at full load. The feasibility of the proposed converter is verified by the experimental results of a 1.5 kW prototype.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.9
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• pp.934-942
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• 2007

In this study, the characteristics of the load-sensitive hydraulic control system for closed center type of a wheel loader were analyzed using developed analysis program based on Amesim tool. From the parametric analysis, the effects of each factor were revealed. Through the simulation with varying parameters, the system parameter effects on the controllable region and the pump pressure and load pressure variations were studied. The results were compared with the experimental ones. The results and discussions of the present paper could aid in the design of a load-sensitive hydraulic control system for closed center type.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.227-228
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• 2013

The paper is related to smart maximum power system based on program logic. Especially, this system compares the total demand power with the target power by using the signal from the digital kilo watt meter. Based on the power information by the maximum power control equipment the consumed future power is anticipated. In addition, through consumed future power the controllable target power is set, and it applies on the maximum power control equipment. User or manager would control the load efficiently through the simple programming which could control load based on the control sequence and relay. So this system could control load more efficient and stable. Also the conventional load control circuit is not needed. Therefore, it is possible to improve the simple system configuration, which is resulted in cost effective and time saving. So this system is anticipated on time and coast.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2668-2670
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• 2004

This paper presents an advanced load control method in Direct Load Control(DLC) system. It is important to aggregate a various demand side resource which is surely controllable at the peak power time for a successful DLC system. Because the DLC system use simple On/Off control that may cause a harmful effect on a plant to reduce a peak power load, there are some restriction on deriving a voluntary participation of demand side resource. So it needs a new approach to direct load control method, and this paper describes an advanced load control method using control logic which is based on load properties. This method is easy to take account of a various characteristic of load, it can be use as a dynamic control logic which is good for adaptive control. The suggested control logic method is verified by modeling a control logic for a turbo refrigerator which affects on peak power in summer season.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.459-467
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• 2012

In this paper, a grid connected microgrid with multiple inverter-based distributed generators (DGs) is considered. DG in FFC mode regulates the microgrid as a controllable load from the utility point of view as long as its output is within the capacity limit. The transition mode causes a change in frequency of microgrid due to the loss of power transferred between main grid and microgrid. Frequency deviation from the nominal value can exceed the limit if the loss of power is large enough. This paper presents a coordinated control method for inverter-based DGs so that the microgrid is always regulated as a constant load from the utility viewpoint during grid connected mode, and the frequency deviation in the transition mode is minimized. DGs can share the load by changing their control modes between UPC and FFC and stabilize microgrid during transition.