• 전기학회논문지
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• 제64권1호
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• pp.41-47
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• 2015

In recent years, energy supply cases to take advantage of EMS(Energy Management System) are increasing according to high interest of energy efficiency. The important factor for essential and economical EMS operation is the supply and demand plan the hourly power demand of building load using the hierarchical clustering method of variety statistical techniques, and use the real historical data of target load. Also the estimated results of study are obtained the reliability through separate tests of validity.

• 전기학회논문지
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• 제65권6호
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• pp.946-954
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• 2016

Energy industry is undergoing a paradigm shift in customer participation in the smartgrid. Customers traditionally consume electrical power. But nowadays not only do they generate electricity from private distributed generations, they can participate in demand response programs with their negawatt power which means a theoretical unit of power representing an amount of energy saved. Therefore development of decision-making criteria for electric load aggregation becomes a greater consideration as an amount of energy saved from demand response resources increases. This paper proposes load aggregators' decision-making criteria in the industrial sector where it made up the largest portion in demand response portfolio in order to assure reliability performance for demand response resources.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.630-632
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• 2003

This paper describes allocation strategies of controllable loads for load aggregator in power market with the direct load control (DLC) program, which is carried out the two-way confirmation procedure. So, it is needed to the priority among the controllable loads to perform effectively and quickly the confirmation task. In this paper, allocation strategies for market operator and/or load aggregator are proposed, which are based on the basic load patterns defined in this paper. To verify the soundness of proposed strategies. case study on a sample system is performed.

• 전력전자학회논문지
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• 제18권5호
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• pp.413-421
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• 2013

This paper proposes residential hybrid distribution system that can supply AC power and DC power to AC load and DC load at the same time. This hybrid distribution system consists of three parts: bidirectional inverter, step-up converter and step-down converter. Also that is used to supply voltage to home application is classified of AC load and DC load as load characteristics. The performance of proposed hybrid distribution system is validated through the hardware implementation and the experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.414-416
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• 1992

두팔 robot의 dynamic model 에 위치 및 힘의 제어를 적용했을때의 부하분배의 관한 연구가 논문의 주요내용이다. 두팔 robot의 완전한 control을 위해서는 위치 뿐만아니라 힘이 제어를 하여야하며 그럴때의 전제 동력학 식의 타당성 여부를 알기위해서는 안정도 연구를 하여야 한다. 그리고 위치 및 힘의 제어를 했을때의 Load의 distribution 문제에 대하여 언급했다. 이에 관한 연구도 연재 많이 진행되고 있으며 여기서 소개하는 방법은 Load 및 end-effector의 힘의 분포에 주안점을 두어서 해석을 하였다. 이 경우에 Load의 분포에 관한 최적해를 얻기위해서는 두팔에서 소모되는 에너지의 최소치를 찾는 방법과 또 하나는 Load에서 형성되는 힘의 기하학적 구조에 대한 2가지 해석을 하였다. Load의 힘의 분포를 해석하기 위해서는 Load의 동작에 무관하게 적용되는 internal force를 가정하였다.

• 전기학회논문지
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• 제65권4호
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• pp.567-575
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• 2016

This paper proposed the voltage control of stand-alone inverter for power quality improvement under unbalanced and non-linear load. The 3-phase DC-AC inverter controls CVCF(Constant Voltage Constant Frequency) and selective harmonic eliminate method in stand-alone mode by PR controller, and the stand-lone inverter supplies stable sinusoidal voltage to balanced, unbalanced and non-linear loads. The total harmonic distortion(THD) of line-to-line load voltage($V_{LL}$) is 1.2% in the balanced load. THD of $V_{LL}$ is reduced from 5.2% to 1.4% and 6.7% to 3.5%, respectively unbalanced and non-linear load. The stand-alone inverter can be supplies sinusoidal balanced voltage to unbalanced load because the voltage unbalanced factor(VUF) of $V_{LL}$ is reduced from 5.2% to 1.4% in the unbalanced load. Feasibility of control method for a stand-alone inverter will be verified through 30kW stand-alone inverter system.

• 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.

• 전기전자학회논문지
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• 제25권3호
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• pp.506-510
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• 2021

본 논문에서는 current detection 구조로 인하여 load regulation의 변화를 향상시킨 LDO를 제안하였다. 제안된 LDO 레귤레이터는 출력단에 제안된 current detection 회로를 추가하였다. 그로인하여 출력에 부하전류에 따른 전압 값의 regulation을 향상시켜 기존 LDO 레귤레이터보다 load Regulation의 변화량을 향상시켰다. 제안한 current detection 구조를 사용하여 부하전류의 변화에 따른 출력 변화를 약 60 % 가량 향상시킬 수 있었다. Cadence의 Virtuoso, Spectre 시뮬레이션을 사용하여 특성을 시뮬레이션 및 검증하였다.

• 대한전기학회논문지:전력기술부문A
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• 제50권6호
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• pp.279-286
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• 2001

A load modeling, micro method, is performed by component load modeling, load composition rate estimation and aggregation of component load model, etc. The load model obtained from this process must be applied to actual load bus to verify it and to get reliable load model. But it is difficult to apply every load bus due to al lot of load buses and complex experiment. This paper proposed the field test method in load bus to verify the load modeling. For appropriate field test, representative load buses are selected by the proposed algorithm considering the composition rate of user category in all load buses. The field tests were performed at selected load buses to obtain load characteristics of bus by time and seasonal without blackout. The results of measurement and analysis are presented in detail.

• 한국전기전자재료학회논문지
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• 제25권5호
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• pp.403-408
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• 2012

In this paper, we propose useful load flow algorithms called FEDL (fast enhanced decoupled load flow). The proposed load flow method can improve the convergence characteristics particularly when the P-Q coupling becomes significant and the power system operating states deviate from the conditions required for stable convergence of the FDL by reflecting in part the effects of the off-diagonal terms in the Jacobian. In our test with IEEE AEP-30 bus system and RTS-96 73-bus system, it converge even when the fast decoupled load flow (FDL) and its variations keeping load flow matrices constant experience convergence problems. Test results show promising performances of the proposed algorithms in their convergence characteristics both in number of iterations and overall convergence speeds.