• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.9
• /
• pp.1610-1617
• /
• 2016

To execute load curtailment efficiently for Urban Railway Load, the load patterns of the Urban Railway Load and available amount of load curtailment over the Urban Railway Load are analyzed through comparing the load to the common power loads. In addition, the current policies of the load curtailment for the Urban Railway Load are investigated and the problems of those are presented. Based on the researches, the optimal load curtailment strategies for the Urban Railway Load are proposed to minimize the consumer's utility diminishment and the costs of the use of energies. Finally, the optimal load curtailment strategies are applied to the real Urban Railway Load, the results shows that proposed methods are efficient and cost effective while the amount of load curtailment is minimized.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.26 no.2
• /
• pp.106-111
• /
• 2021

This study proposes a control method to mitigate the influence of input capacitors in photovoltaic power curtailment. The influence is analyzed by the power flow in the photovoltaic system. In conventional power curtailment, the power injected to the grid may be increased momentarily because the influence of the input capacitor on the power injected to the grid is not considered. The proposed method limits the change rate of photovoltaic array voltage to prevent a momentary increase in the power injected to the grid. The effectiveness of proposed method, which reduces power overshoot, is verified by experimental tests. The proposed method enables the power grid to operate stably in photovoltaic power curtailment.

• New & Renewable Energy
• /
• v.18 no.2
• /
• pp.50-59
• /
• 2022

The Korean government announced the "1st Basic Plan for the Transition to Hydrogen Economy" in 2021 and declared the establishment of a hydrogen industry ecosystem by 2040. To build a low-carbon power system, resources that can efficiently accommodate renewable energy are required, and green hydrogen is considered a potential solution. This study analyzed the economic feasibility of green hydrogen-based sector coupling to reduce curtailment of renewable generation in the Jeju power system by 2025 under the scenario of with or without HVDC#3. The result showed that HVDC#3 significantly reduced the frequency of curtailment from 16.1% to 3.0%. In addition, green hydrogen-based sector coupling was an economically feasible option as result showed an IRR of 4.86% when HVDC#3 was connected and 11.45% when it was not under the condition of achieving 50% curtailment reduction. This study shows that the higher the level of renewable energy deployment, the more delayed the HVDC connection between Jeju and the main land, and the lower the SMP, the more economically feasible the green hydrogen-based sector coupling is. Furthermore, this study suggests that the policy goal of completely reducing curtailment is not economically efficient.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.5
• /
• pp.18-25
• /
• 2016

This research purposed to study a structural effect on curtailment of upper shear wall in frame-shear wall structures, using MIDAS-Gen. In this study, the analysis variables were the story number of curtailment of upper shear wall, change of column section in every 2 stories and change of shear wall thickness in every 2 stories. In order to analyse a structural effect on curtailment of upper shear wall in frame-shear wall structures, we studied the distribution of shear force and overturning moment according to curtailment of shear wall, the inflection point of shear wall from shear force/overturning moment and the lateral stiffness. The results of study proposed the quantitative influence that the curtailment of upper shear wall in frame-shear wall structures had on the structural performance such as lateral stiffness. Furthermore, it is verified that the results of study can be very helpful in catching the materials on the structure design for a reasonable frame-shear wall system.

• Korea Journal of Hospital Management
• /
• v.8 no.2
• /
• pp.93-110
• /
• 2003

Fiscal crisis in the medical insurance has put the pressure upon hospitals by increasing the rate of curtailment, since the implementation of the separation between prescription and dispensing of Drug. The purpose of this study is to analyze the curtailment for antibiotics, injected drug and other drugs expenditure before and after the system of separation between prescribing and dispensing. Data were gathered from 13 general hospitals and used for analysis of trends on antibiotics and injected drug expenditure, and curtailment in 2000-2001 at three months intervals. The results were as follows; The curtailment rate of antibiotics expenditure has been increased in outpatient and inpatient since 2000. The curtailed antibiotics cost and injected drug cost in outpatient under the prescription within the hospital and in inpatient increased. The ratios of curtailment versus expenditure had increased in antibiotics, injected drugs, anticancer drugs, antiulcer drugs, albumine, antiinflammatory drugs. These results suggest that claim review system in social health insurance were over-focused mainly to control the cost and it might to impede the validity of claim review function in health insurance system. Therefore, it's needed to develope the scientific and reasonable parameter & criteria for claim review of drug expenditure.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.2
• /
• pp.158-164
• /
• 2018

Wind power forecast is critical for efficient power system operation. However, wind power has high forecasting errors due to uncertainty caused by the climate change. These forecasting errors can have an adverse impact on the power system operation. In order to mitigate the issues caused by the wind power forecasting error, wind power curtailment and energy storage system (ESS) can be introduced in the power system. These methods can affect the economics of wind power resources. Therefore, it is necessary to evaluate the economics of the methods for mitigating the wind power forecasting error. This paper attempts to analyze the economics of wind power curtailment and ESS operation for mitigating wind power forecasting error. Numerical simulation results are presented to show the economic impact of wind power curtailment and ESS operation.

• Health Policy and Management
• /
• v.12 no.3
• /
• pp.23-35
• /
• 2002

Fiscal crisis in the medical insurance system has put the pressure upon hospitals by increasing the rate of curtailment, since the implementation of the separation of prescription and dispensing of medicine. The purpose of this study is to analyse the curtailment of mdical and drug expenditure before and after the system of separation between prescribing and dispensing and to suggest the problems about current inspection system. Data were obtained from 13 general hospitals and used for analysis of trends on medical & drug expenditure, and curtailment in 1999-2000 at three months intervals. The results were as follows; The scale of curtailment for drug expenditure has been increased on outpatient and inpatient since 2000. For the curtailed drug cost with outpatient, the ratio of curtailed drug expenditure has been increased in the case of prescription within the hospital. These results suggest that review system in social insurance were over-focused to control the cost and it might to impede the validity of review function in insurance system. Therefore, it' s needed to develope the scientific and reasonable criteria for Inspection and evaluation of durg expenditure.

• Korea Journal of Hospital Management
• /
• v.10 no.2
• /
• pp.45-63
• /
• 2005

The purposes of this study are to understand the doctors' attitude and satisfaction about the review system of national health insurance claim in Korea and to suggest the way to improve this system This study conducted a survey of the doctors registered in the medical association in Seoul city. The survey was performed as a form of self-administered questionnaire from January 2004 to February 2004. The contents of questionnaire dealt with doctors' attitude and satisfaction about the review system of medical service claim. Totally, 1,037 members replied to our survey and we analysed 981 doctors' data, excluding incomplete responses. As a result, 89.7% of repliers showed a negative attitude about the influences of the review system on improvement of medical service quality, 98.0% of repliers have had experiences that they have given distorted insufficient medical services in order to evade the curtailment of service claim. Also, 91.6% of repliers stated that they have had experiences of intentional modification or alteration of diagnostic code to shun the curtailment. Most of the doctors showed negative attitude to the curtailment procedure and the review system of service claim originally intended to be one of the quality control methods of medical service in Korea also, the development of both scientific and reasonable parameters and criteria for claim is needed. 'Through the improvement of review system for appropriate medical service, there is a need of a way to increase the satisfaction of medical service providers, and to encourage the motivation for quality control. Also, education is strongly needed to provide doctors with sufficient information about review criteria and curtailment cases.

• Proceedings of the KIEE Conference
• /
• 2003.07a
• /
• pp.633-635
• /
• 2003

Electricity industries throughout the world are undergoing unprecedented changes. As a result, these changes lead to the separation of traditional integrated utilities and the introduction of competition in order that increase efficiency in electricity industry. Direct load control (DLC) system in competitive electricity market has a hierarchical interactive operation system, therefore, its control logic is also applied by bilateral interactive method that interchanges information related to interruptible load between operation hierarchies. Consequently, load curtailment allocation algorithm appropriate for new DLC system is required, and based on interchanged information, this algorithm should be implemented by most efficient way for each operation hierarchy. In this paper, we develop the load curtailment allocation algorithm in an emergency for new DLC system. Especially, the optimal algorithm for load aggregator (LA) that participates in competitive electricity market as a main operator for load management is developed.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.8
• /
• pp.466-471
• /
• 2004

Electricity industries throughout the world are undergoing unprecedented changes. As a result, these changes lead to the separation of traditional integrated utilities and the introduction of competition in order that increase efficiency in electricity industry. Direct load control (DLC) system in competitive electricity market has a hierarchical interactive operation system, therefore, its control logic is also applied by bilateral interactive method that interchanges information related to interruptible load between operation hierarchies. Consequently, load curtailment allocation algorithm appropriate for new DLC system is required, and based on interchanged information, this algorithm should be implemented by most efficient way for each operation hierarchy. In this paper, we develop the load curtailment allocation algorithm in an emergency for new DLC system. Especially, the optimal algorithm for load aggregator (LA) that participates in competitive electricity market as a main operator for load management is developed.