• Title/Summary/Keyword: electrical load

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Development of Control Algorithm and Detection of the Small Leakage Current (미소 누전전류 검출 및 차단제어기 설계)

  • 반기종;김낙교
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.3
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    • pp.161-165
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    • 2004
  • In this paper, we have designed the ground faults detection and interrupting controller at normal condition of AC 120v to 240v rating voltage. Ground faults in electrical network have the characteristics of low current, 60㎐ frequency to 2㎑frequency. The load condition are no load and 20A load. The trip level of the controller is 6㎃ with ground faults. The Controller algorithm is implemented using pic16c71 microprocessor.

Reasonable Load Characteristic Experiment for Component Load Modeling (개별 부하모델링을 위한 부하의 합리적인 특성실험)

  • Ji, Pyeong-Sik;Lee, Jong-Pil;Im, Jae-Yun;Chu, Jin-Bu;Kim, Jeong-Hun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.2
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    • pp.45-52
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    • 2002
  • Load modeling is classified into two methods according to approaching method, so called the measurement and component-based method. The measurement method is to model the load characteristics measured directly at substations and feeders. But it is difficult to measure continuously load characteristics from naturally occurring. system variation. The component-based method consists of the fellowing process; component load modeling, composition rate estimation and aggregation of component loads, etc. In this paper, the characteristic experiment of component loads was performed to obtain data for the component load modeling as the component-based method. At first, representative component loads were selected by the proposed method considering the accuracy of load modeling and the performance possibility of component load experiment in the laboratory. Also an algorithm was Proposed to identify the reliability of data obtained from the component load characteristic experiments. In addition, the results were presented as the case studies.

A Low Drop Out Regulator with Improved Load Transient Characteristics and Push-Pull Pass Transistor Structure (Push-Pull 패스 트랜지스터 구조 및 향상된 Load Transient 특성을 갖는 LDO 레귤레이터)

  • Kwon, Sang-Wook;Song, Bo Bae;Koo, Yong-Seo
    • Journal of IKEEE
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    • v.24 no.2
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    • pp.598-603
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    • 2020
  • In this paper present a Low Drop-Out(LDO) regulator that improves load transient characteristics due to the push-pull pass transistor structure is proposed. Improved load over the existing LDO regulator by improving the overshoot and undershoot entering the voltage line by adding the proposed push-pull circuit between the output stage of the error amplifier inside the LDO regulator and the gate stage of the pass transistor and the push-pull circuit at the output stage. It has a delta voltage value of transient characteristics. The proposed LDO structure was analyzed in Samsung 0.13um process using Cadence's Virtuoso, Spectre simulator.

Reliability Computation of Neuro-Fuzzy Model Based Short Term Electrical Load Forecasting (뉴로-퍼지 모델 기반 단기 전력 수요 예측시스템의 신뢰도 계산)

  • Shim, Hyun-Jeong;Wang, Bo-Hyeun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.54 no.10
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    • pp.467-474
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    • 2005
  • This paper presents a systematic method to compute a reliability measure for a short term electrical load forecasting system using neuro-fuzzy models. It has been realized that the reliability computation is essential for a load forecasting system to be applied practically. The proposed method employs a local reliability measure in order to exploit the local representation characteristic of the neuro-fuzzy models. It, hence, estimates the reliability of each fuzzy rule learned. The design procedure of the proposed short term load forecasting system is as follows: (1) construct initial structures of neuro-fuzzy models, (2) store them in the initial structure bank, (3) train the neuro-fuzzy model using an appropriate initial structure, and (4) compute load prediction and its reliability. In order to demonstrate the viability of the proposed method, we develop an one hour ahead load forecasting system by using the real load data collected during 1996 and 1997 at KEPCO. Simulation results suggest that the proposed scheme extends the applicability of the load forecasting system with the reliably computed reliability measure.

Comparative Analysis of Voltage Unbalance Factor on the use of Linear and Non-linear loads in Three-phase Four-wire Low Voltage Distribution Line (3상 4선식 저압 배전선로에서 선형 및 비선형 부하의 사용시 전압 불평형률 비교 분석)

  • Kim, Jong-Gyeum;Kim, Ji-Myeong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.3
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    • pp.587-592
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    • 2017
  • In the three-phase four-wire low-voltage power distribution equipment, single-phase and three-phase load have been used mainly mixed. Also linear and nonlinear loads have been used together in the same conditions. In a three-phase four-wire distribution line, the current distribution of three-phase linear load is almost constant in each phase during driving or stopping, but the single-phase load is different from each other for each phase in accordance with the operation and stop. So that the voltage unbalance is caused by the current difference of each phase. In the three-phase four-wire distribution system, non-linear load is used with linear load. The presence of single-phase nonlinear loads can produce an increase in harmonic currents in three-phase and neutral line. It can also cause voltage unbalance. In the present study, we analyzed for the voltage unbalance fluctuations by the operation pattern of the single and three-phase linear and non-linear load in three-phase four-wire low voltage distribution system.

Spatio-temporal Load Forecasting Considering Aggregation Features of Electricity Cells and Uncertainties in Input Variables

  • Zhao, Teng;Zhang, Yan;Chen, Haibo
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.38-50
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    • 2018
  • Spatio-temporal load forecasting (STLF) is a foundation for building the prediction-based power map, which could be a useful tool for the visualization and tendency assessment of urban energy application. Constructing one point-forecasting model for each electricity cell in the geographic space is possible; however, it is unadvisable and insufficient, considering the aggregation features of electricity cells and uncertainties in input variables. This paper presents a new STLF method, with a data-driven framework consisting of 3 subroutines: multi-level clustering of cells considering their aggregation features, load regression for each category of cells based on SLS-SVRNs (sparse least squares support vector regression networks), and interval forecasting of spatio-temporal load with sampled blind number. Take some area in Pudong, Shanghai as the region of study. Results of multi-level clustering show that electricity cells in the same category are clustered in geographic space to some extent, which reveals the spatial aggregation feature of cells. For cellular load regression, a comparison has been made with 3 other forecasting methods, indicating the higher accuracy of the proposed method in point-forecasting of spatio-temporal load. Furthermore, results of interval load forecasting demonstrate that the proposed prediction-interval construction method can effectively convey the uncertainties in input variables.

An Improved Spatial Electric Load Forecasting Algorithm (개선된 지역수요예측 알고리즘)

  • Nam, Bong-Woo;Song, Kyung-Bin
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.05a
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    • pp.397-399
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    • 2007
  • This paper presents multiple regression analysis and data update to improve present spatial electric load forecasting algorithm of the DISPLAN. Spatial electric load forecasting considers a local economy, the number of local population and load characteristics. A Case study is performed for Jeon-Ju and analyzes a trend of the spatial load for the future 20 years. The forecasted information can contribute to an asset management of distribution systems.

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The Daily Peak Load Forecasting in Summer with the Sensitivity of Temperature (온도에 대한 민감도를 고려한 하절기 일 최대전력수요 예측)

  • 공성일;백영식;송경빈;박지호
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.6
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    • pp.358-363
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    • 2004
  • Due to the weather sensitivity of the power load, it is difficult to forecast accurately the peak power load of summer season. We improve the accuracy of the load forecasting considering weather condition. We introduced the sensitivity of temperature and proposed an improved forecasting algorithm. The proposed algorithm shows that the error of the load forecasting is 1.5%.

Estimation of Electrical Loads Patterns by Usage in the Urban Railway Station by RNN (RNN을 활용한 도시철도 역사 부하 패턴 추정)

  • Park, Jong-young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.11
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    • pp.1536-1541
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    • 2018
  • For effective electricity consumption in urban railway station such as peak load shaving, it is important to know each electrical load pattern by various usage. The total electricity consumption in the urban railway substation is already measured in Korea, but the electricity consumption for each usage is not measured. The author proposed the deep learning method to estimate the electrical load pattern for each usage in the urban railway substation with public data such as weather data. GRU (gated recurrent unit), a variation on the LSTM (long short-term memory), was used, which aims to solve the vanishing gradient problem of standard a RNN (recursive neural networks). The optimal model was found and the estimation results with that were assessed.