• 한국지능시스템학회논문지
• /
• 제19권2호
• /
• pp.197-205
• /
• 2009

미래 디지털 환경에서 에너지 관리 시스템은 예기치 못한 정전이나 과부하 같은 응급 상황 이벤트들이 발생하면 이를 실시간으로 대처할 수 있어야 하고, 원격 검침과 같은 소비자 서비스 이벤트들도 신속하게 제공되어야 한다. 따라서 다양한 에너지 이벤트 정보들을 실시 간으로 전달할 수 있는 단순하면서 장치 독립적인 정보 교환 모델이 필요하다. 이에 본 논문에서는 XML을 기반으로 객체 지향 모델링을 사용하여 장치와 이벤트 모델링을 분리한 esXML을 개발하였다. 실험 결과 독립적이고 효율적으로 정보 교환을 할 수 있었다.

• 한국컴퓨터정보학회논문지
• /
• 제23권10호
• /
• pp.57-63
• /
• 2018

The operating system for an isolated microgrid, which is completely disconnected from the central power system, aims at preventing blackouts and minimizing power generation costs of diesel generators through efficient operation of the energy storage system (ESS) that stores energy produced by renewable energy generators and diesel generators. In this paper, we predict the amount of renewable energy generation using the weather forecast and build an optimal diesel power generation plan using a genetic algorithm. In order to avoid inefficiency due to inaccurate prediction of renewable energy generation, our search algorithm imposes penalty on candidate diesel power generation plans that fail to maintain the SOC (state of charge) of ESS at an appropriate level. Simulation experiments show that our optimization method for maintaining an appropriate SOC balance can prevent the blackout better when compared with the previous method.

• Journal of Electrical Engineering and Technology
• /
• 제5권2호
• /
• pp.191-196
• /
• 2010

Power system restoration following a massive or complete blackout starts with energizing the primary restorative transmission system. During this primary restoration process, unexpected overvoltage may happen due to nonlinear interaction between the unloaded transformer and the transmission system. In the case of the Myanmar electric power system, there are so many wide outage experiences, including complete blackout cases, caused by 230kV line faults and so on. Consequently, Myanmar's system operators have been well trained to deal with wide blackouts. Howver, system blackout restoration has been conducted by relying on the experience of only a few specialists. So, more scientific analysis is required to meet the requirements necessary to ensure fast and reliable system restoration. This paper presents analytical results on the primary restorative transmission system of Myanmar, focusing on the problems during the early restoration process. Methodologies are presented that handle load pick-up, terminal voltage and the reactive capability limitation of black-start generators to compensate the Ferranti effect. Static and dynamic simulation with the PSSolution and EMTDC programs respectively for the six cases are performed in order to select the primary restorative transmission lines.

• 전기학회논문지
• /
• 제66권3호
• /
• pp.507-512
• /
• 2017

Recently, more electric power facilities have been miniaturized and it is noted that the facilities maintenance will be essential through operation optimization. In this paper we applied and examined the operation optimization of electric power facilities by applying Matrix system which can improve reliability to minimize outage and recover failure rapidly when blackouts happen at 25.8kV Gas Insulated Switchgear(GIS). The fundamental problem for facilities maintenance of GIS can happen due to indeterminable internal state in real time. Matrix optimization organizes action states in all containers which contain pressurized $SF_6$ Gas such as circuit breaker, disconnector switch, bus for utilizing them each area. Then, we connect it with power system to monitor and control internal state remotely in real time, and we can minimize blackout zone or outage. Considering above process, we improved stability of overall facilities.

• Journal of Electrical Engineering and Technology
• /
• 제13권1호
• /
• pp.1-10
• /
• 2018

Wide-area monitoring of tree-related high impedance fault (THIF) efficiently contributes to increase reliability of large-scaled network, since the failure to early location of them may results in critical lines tripping and consequently large blackouts. In the first place, this wide-area monitoring of THIF requires managing the placement of sensors across large power grid network according to THIF detection objective. For this purpose, current paper presents a framework in which sensors are distributed according to a predetermined risk map. The proposed risk map determines the possibility of THIF occurrence on every branch in a power network, based on electrical conductivity of trees and their positions to power lines which extracted from spectral data. The obtained possibility value can be considered as a weight coefficient assigned to each branch in sensor placement problem. The next step after sensors deployment is to on-line monitor based on moving data window. In this on-line process, the received data window is evaluated for obtaining a correlation between low frequency and high frequency components of signal. If obtained correlation follows a specified pattern, received signal is considered as a THIF. Thereafter, if several faulted section candidates are found by deployed sensors, the most likely location is chosen from the list of candidates based on predetermined THIF risk map.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.107-108
• /
• 2007

Overhead transmission lines are completely exposed to the environment. This causes faults in transmission lines due to natural environmental conditions. In some cases, transmission towers are damaged by typhoons and snow, as well as sleet on the transmission lines. It takes a lot of time to repair the damaged towers. For emergency restoration purposes, steel poles are installed to temporarily supply power. Before 2003, emergency restoration steel poles were made of angled steel, which required a large number of beams, bolts, etc. In addition, the foundation of the steel pole and ground wire was constructed using excavation and burial methods, therefore it required a lot of manpower and time to construct temporary transmission lines. In September 2003, typhoon Maemi, whose maximum wind speed was 60m/s, hit Korea. 'Maemi' destroyed transmission lines in the Busan and Geojea area, causing long blackouts. To reduce the recovery time to the damaged transmission lines, self-build based emergency towers were developed. self-build based emergency towers reduced recovery time from 24 hours to 4 hours or less. However, the self-build based emergency tower had no arms, so the temporary transmission lines could only be constructed without curves in line routes. In this paper, solving these self-build based emergency tower limitations, using insulated arms(designed for use with the self-build based emergency tower), shall be explained.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제57권4호
• /
• pp.371-391
• /
• 2018

The purpose of this study is to analyze manifestation examples and effects of group creativity in mathematical modeling and to discuss teaching and learning methods for group creativity. The following two points were examined from the theoretical background. First, we examined the possibility of group activity in mathematical modeling. Second, we examined the meaning and characteristics of group creativity. Six students in the second grade of high school participated in this study in two groups of three each. Mathematical modeling task was "What are your own strategies to prevent or cope with blackouts?". Unit of analysis was the observed types of interaction at each stage of mathematical modeling. Especially, it was confirmed that group creativity can be developed through repetitive occurrences of mutually complementary, conflict-based, metacognitive interactions. The conclusion is as follows. First, examples of mutually complementary interaction, conflict-based interaction, and metacognitive interaction were observed in the real-world inquiry and the factor-finding stage, the simplification stage, and the mathematical model derivation stage, respectively. And the positive effect of group creativity on mathematical modeling were confirmed. Second, example of non interaction was observed, and it was confirmed that there were limitations on students' interaction object and interaction participation, and teacher's failure on appropriate intervention. Third, as teaching learning methods for group creativity, we proposed students' role play and teachers' questioning in the direction of promoting interaction.

• The Journal of Asian Finance, Economics and Business
• /
• 제8권9호
• /
• pp.261-272
• /
• 2021

Rapid economic growth in recent years has caused a surge in energy consumption among Southeast Asian countries and laid a considerable burden on the already inadequate power infrastructure. As a result, frequent blackouts and prolonged outages have become common and weakened firm productive performance in those years. The main objective of this study is to examine the impact of power infrastructure quality on the performance of Southeast Asian manufacturing firms. In this study, the World Bank Enterprise Surveys was employed as the training dataset of 4723 manufacturing firms in the period of 2015-2016. The results of this study reveal that industrial firms that suffered from power outages had consistently lower productivity. As measured by the length of such events, more severe outages tend to be more harmful to the firm. Furthermore, the findings also indicated that most firms relied on self-generated electricity to reduce the negative impact of power outages, but this does not bring many benefits when operating at a small scale in some countries. Consequently, this study contributes to a growing literature that examines the economic impact of public infrastructure and how detrimental the poor state of such services is to a firm's downstream operations, productivity, and growth.

• Nuclear Engineering and Technology
• /
• 제54권2호
• /
• pp.749-763
• /
• 2022

The fulcrum of economic development is a sustainable supply of electricity. Nigeria is plagued with blackouts, with one of the lowest per capita electricity consumption in the world (circa. 120 kWh per capita). Hence, policies have been instigated to integrate electricity generation from nuclear power plants (NPP) on or before 2027. However, a critical requirement for NPP generation is the implementation of robust human resource development (HRD) programs. This paper presents the perspective of Nigeria in assessing human resources needs over the entire NPP lifecycle following the milestone approach and employing the IAEA's Nuclear Power Human Resource (NPHR) modeling tool. Three workforce organizations are in focus including the owner/operator, regulators, and construction workers following three decades timeframe (2015-2045). The results indicate that for the study period, a maximum of approximately 9045 personnel (73% construction workers, 24% owner/operator, and 3% regulators) should be directly involved in the NPP program just before the commissioning of the third NPP in 2033. However, this number decreases by about 73% (2465 personnel including 94% operator and 6% regulator) at the end of the study timeframe. The results can potentially provide clarity and guidance in HRD decision-making programs.

• 한국컴퓨터정보학회논문지
• /
• 제14권8호
• /
• pp.89-96
• /
• 2009

향후 에너지 환경에서 전력 관리 시스템은 예기치 못한 정전이나 과부하 같은 응급 상황 이벤트들이 발생하면 이를 실시간으로 대처할 수 있어야 하고, 원격 검침과 같은 소비자 서비스 이벤트들도 신속하게 제공되어야 한다. 뿐만 아니라, 시스템에서 발생되는 대용량의 정보들을 효과적으로 처리할 수 있는 기능도 필요하다. 이에 본 논문에서는 정보교환에 효율적인 XML(eXtensible Markup Language)을 이용하여 이벤트에 기반하며 대용량의 정보들을 부하 균형시키고, 핫 스폿(hot spot)을 줄일 수 있는 메타 데이터 처리 기법이 적용된 분산 전력 정보 관리 시스템을 개발하였다. 개발된 시스템을 실험하기 위해 무선통신으로 전력 단말기들을 제어할 수 있는 축소된 미래 전력 시스템을 제작한 후, 이를 통해 실험을 수행하였다.