• 제목/요약/키워드: power normalization

검색결과 105건 처리시간 0.026초

KPX의 한국 전력 계통에서 EMS 계통해석기능 활용실태 소개 (KPX's EMS Network Analysis Operation Status in Korea Power System)

  • 강형구;한희천
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
    • /
    • pp.30-34
    • /
    • 2005
  • Due to old Toshiba EMS's database size limit and hardware old aging, KPX(Korea Power Exchange) had introduced New EMS from AREVA(old ALSTOM) in July 2002. After then KPX had committed many man power and time to normalize EMS NA(Network Analysis) functions for using real power system. At initial stage, to normalize State Estimator which is the backbone of all other NA functions and DTS(Dispatcher Training Simulator}, KPX had corrected numerous topology errors, network model errors, non-scanned and wrongly scanned SCADA measured errors. After SE function study, running test and tuning, State Estimator could finally have been run properly and stably from June 2003. Based on SE running, KPX had normalized real time Contingency Analysis, and study mode Power Flow, STNET and DTS. From early 2004, dispatchers have been trained to use NA and DTS for the purpose of stable SE running, NA operation & results reading and urgent equipment outage reviewing. EMS NA have been greatly contributed to operate real time power system stably. Above NA normal operation by KPX own efforts under the no experience of NA running, KPX made a good precedent. This paper is intended to introduce EMS NA normalization process, operation status, and etc in Korea power system operation.

  • PDF

발전 제어시스템의 융합보안 연구 (A Study on Convergence Security of Power Generation Control System)

  • 이대성
    • 융합보안논문지
    • /
    • 제18권5_1호
    • /
    • pp.93-98
    • /
    • 2018
  • 한국수력원자력, 한국전력공사, 한국남동발전 등의 발전 제어시스템은 전력을 공급하는 국가의 주요 인프라 시설로 악의적인 해킹 공격이 진행될 경우 그 피해는 상상을 초월한다. 실제로 한국수력원자력은 해킹 공격을 당하여 내부정보가 유출되는 등 사회적인 큰 문제를 야기하였다. 본 연구에서는 최근 이슈가 되고 있는 융합보안 연구에 대해 전력회사 중심의 발전 제어시스템을 대상으로 그 환경을 분석하고, 현황을 분석하여 다양한 발전 제어시스템의 안정화를 위한 전략체계 수립과 대응책을 제시하고자 한다. 다양한 물리적 보안시스템(시설), IT 보안시스템, 출입통제시스템 등에서 나오는 데이터 형태를 정규화하고 통합하여 융합인증을 통해 전체 시스템을 통제하고, 융합관제를 통해 위험을 탐지하는 방법을 제안한다.

  • PDF

A note on Box-Cox transformation and application in microarray data

  • Rahman, Mezbahur;Lee, Nam-Yong
    • Journal of the Korean Data and Information Science Society
    • /
    • 제22권5호
    • /
    • pp.967-976
    • /
    • 2011
  • The Box-Cox transformation is a well known family of power transformations that brings a set of data into agreement with the normality assumption of the residuals and hence the response variable of a postulated model in regression analysis. Normalization (studentization) of the regressors is a common practice in analyzing microarray data. Here, we implement Box-Cox transformation in normalizing regressors in microarray data. Pridictabilty of the model can be improved using data transformation compared to studentization.

A Real-Time Method for the Diagnosis of Multiple Switch Faults in NPC Inverters Based on Output Currents Analysis

  • Abadi, Mohsen Bandar;Mendes, Andre M.S.;Cruz, Sergio M.A.
    • Journal of Power Electronics
    • /
    • 제16권4호
    • /
    • pp.1415-1425
    • /
    • 2016
  • This paper presents a new approach for fault diagnosis in three-level neutral point clamped inverters. The proposed method is based on the average values of the positive and negative parts of normalized output currents. This method is capable of detecting and locating multiple open-circuit faults in the controlled power switches of converters in half of a fundamental period of those currents. The implementation of this diagnostic approach only requires two output currents of the inverter. Therefore, no additional sensors are needed other than the ones already used by the control system of a drive based on this type of converter. Moreover, through the normalization of currents, the diagnosis is independent of the load level of the converter. The performance and effectiveness of the proposed diagnostic technique are validated by experimental results obtained under steady-state and transient conditions.

Site calibration이 풍력발전시스템 성능시험 불확도에 미치는 영향 연구 (A Study for the Effect on the Uncertainty of Power Performance Testing of Windturbine by a Site Calibration)

  • 김건훈;현승건
    • 한국태양에너지학회 논문집
    • /
    • 제31권2호
    • /
    • pp.107-112
    • /
    • 2011
  • A comparison study between two performance testing results, one is on the site calibration not needed and the other is needed, was proceeded for the understanding on the effect of site calibration on the complex terrain. As a result, it is revealed that all of uncertainty components is effected by the topographical features dramatically. And the maximum difference of uncertainty reached at around 8% of rated capacity of wind turbine. So, the site calibration is an effective method to remove the variable wind effect by the ground complexity and must be proceeded before the power performance testing of a wind turbine.

Development of an Adaptive Neuro-Fuzzy Techniques based PD-Model for the Insulation Condition Monitoring and Diagnosis

  • Kim, Y.J.;Lim, J.S.;Park, D.H.;Cho, K.B.
    • E2M - 전기 전자와 첨단 소재
    • /
    • 제11권11호
    • /
    • pp.1-8
    • /
    • 1998
  • This paper presents an arificial neuro-fuzzy technique based prtial discharge (PD) pattern classifier to power system application. This may require a complicated analysis method employ -ing an experts system due to very complex progressing discharge form under exter-nal stress. After referring briefly to the developments of artificical neural network based PD measurements, the paper outlines how the introduction of new emerging technology has resulted in the design of a number of PD diagnostic systems for practical applicaton of residual lifetime prediction. The appropriate PD data base structure and selection of learning data size of PD pattern based on fractal dimentsional and 3-D PD-normalization, extraction of relevant characteristic fea-ture of PD recognition are discussed. Some practical aspects encountered with unknown stress in the neuro-fuzzy techniques based real time PD recognition are also addressed.

  • PDF

몬테소리교육(敎育)에서 아동(兒童)의 정상화과정(正常化過程)에 관한 고찰(考察) (A Study on the Process of Normalizing Children in Montessori's Education)

  • 황옥자
    • 아동학회지
    • /
    • 제5권
    • /
    • pp.107-119
    • /
    • 1984
  • In this article we reviewed the phenomena and processes of normalizing children through documentary records with interest in the aim of Montessori's education methods. The Montessori education method is based on the theory that all children should be respected and their works prized. The normalization of children does not mean only to turn abnormal children into normal ones, but to make normal characteristics - calmness, self-confidence, happiness or patience, etc.- which are latent in themselves, appear on the surface and remold them as new children. To achieve normalization some prerequisites are necessary. They are as follows: 1) The principle of freedom. The freedom in Montessori's education has some limits in prepared environments suitable for developing children as whole persons through their spontaneous activities. 2) Development of the phenomenon of children's attention. Arousal of their attention in the children's primitive inner impulse and sense of spiritual hunger. To satisfy their hunger children divert their interest to certain objects and come to repeated exercise of intelligence. 3) Concentration and repetitive phenomena. Repetition through children's concentration phenomenon is a natural and important fundamental behavior which controls their mental power. Repetitive behavior will form serious discipline and promote development of their intelligence.

  • PDF

화자 정규화를 위한 비정형 워핑함수 도출에 관한 실험 (Experiments on Extraction of Non-Parametric Warping Functions for Speaker Normalization)

  • 신옥근
    • 한국음향학회지
    • /
    • 제24권5호
    • /
    • pp.255-261
    • /
    • 2005
  • 화자들 사이의 워핑특성을 알아보기 위해 비정형 워핑함수를 도출하는 실험을 수행하였다. 이를 위해 모음의 MFCC와 LP 스펙트럼을 이용하여 화자별, 음소별 대표 스펙트럼을 선정한 다음 음소별 기준 스펙트럼을 선택하였다. 기준 스펙트럼과 대표 스펙트럼을 스펙트럼의 전체대역에서 DTW로 비교하여 화자별 워핑함수를 구한 다음, 이들을 clustering함으로써 비정형 워핑함수의 집합을 도출하였다. 이 함수집합에서 남성화자와 여성화자의 함수들이 각각 구간선형함수와 파워함수와 유사함을 관찰할 수 있었으며, 이를 근거로 이 함수들을 조합한 하이브리드 워핑함수집합을 정의하였다. 음소단위의 인식 실험을 통하여 새로 정의된 함수들의 인식률을 시험하였으며 두 함수집합 모두에서 개선된 인식률을 얻을 수 있었다.

족삼리와 상완, 중완, 하완혈의 침 자극으로 기능성 소화불량증 환자의 위 평활근 전기적 활성 장애를 정상화시켰던 증례 2례 (Normalization Effect of Both ST36 and CV11, 12, 13 Meridian Points on the Abnormal Gastric Myoelectrical Activity in Two Cases of Functional Dyspeptic Patients)

  • 윤상협
    • 대한한방내과학회지
    • /
    • 제42권4호
    • /
    • pp.707-717
    • /
    • 2021
  • Objectives: The aim of this study was to introduce the normalization effects of stimulation of both ST36 and CV11, 12, 13 meridian points on the abnormal gastric myoelectrical activity in two cases of functional dyspeptic patients with gastric dysmotility. Methods: Gastric myoelectrical activity was recorded by electrogastrography every two weeks until their gastric myoelectrical activity finally reached the normality. Dominant frequency of gastric slow waves in the fasting and postprandial periods and a dominant power ratio were obtained on each occasion. Patients were treated three times each day: 9 am, 1 pm, and 7 pm. The first treatment consisted of manual and immersion stimulation on all used meridian points for 20 min. In the second and third treatments, electrical stimulation of both ST36 was added. It was conducted for 20 min at a strength intensity of 1.2 times the pain threshold at a frequency of 3 Hz. Results: Stimulation of the above meridian points normalized abnormal gastric myoelectrical activity. The time taken to return from abnormal gastric myoelectrical activity to normal was 16-19 weeks. Conclusion: Stimulation of both ST36 and CV11, 12, 13 meridian points normalized the abnormal gastric myoelectrical activity in the functional dyspepsia of gastric dysmotility.

Research on prediction and analysis of supercritical water heat transfer coefficient based on support vector machine

  • Ma Dongliang;Li Yi;Zhou Tao;Huang Yanping
    • Nuclear Engineering and Technology
    • /
    • 제55권11호
    • /
    • pp.4102-4111
    • /
    • 2023
  • In order to better perform thermal hydraulic calculation and analysis of supercritical water reactor, based on the experimental data of supercritical water, the model training and predictive analysis of the heat transfer coefficient of supercritical water were carried out by using the support vector machine (SVM) algorithm. The changes in the prediction accuracy of the supercritical water heat transfer coefficient are analyzed by the changes of the regularization penalty parameter C, the slack variable epsilon and the Gaussian kernel function parameter gamma. The predicted value of the SVM model obtained after parameter optimization and the actual experimental test data are analyzed for data verification. The research results show that: the normalization of the data has a great influence on the prediction results. The slack variable has a relatively small influence on the accuracy change range of the predicted heat transfer coefficient. The change of gamma has the greatest impact on the accuracy of the heat transfer coefficient. Compared with the calculation results of traditional empirical formula methods, the trained algorithm model using SVM has smaller average error and standard deviations. Using the SVM trained algorithm model, the heat transfer coefficient of supercritical water can be effectively predicted and analyzed.