• Title/Summary/Keyword: System net power

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Implementation of Modular Neural Net for Fault Diagnosis in Power System (전력 계통 사고구간 판정에의 모듈형 신경 회로망의 구현)

  • Kim, Kwang-Ho;Park, Jong-Keun
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.224-227
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    • 1989
  • In this paper, The implementation of modular neural net for fault diagnosis in power system is presented. Until now, there have been many researches on expert system for fault diagnosis. On expert system, a lot of time for searching goal is needed. But, neural net processes with high speed, as it has parallel distributed processing structure. So neural net has good performance in on-line fault diagnosis. For fault diagnosis in large power system, the constitution of modular neural net with partition of large power system is presented.

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VALVELESS PUMPING IN OPEN TANK SYSTEM USING ENERGY CONSERVING COMPARTMENT MODEL

  • Jung, Eun-Ok;Kim, Do-Wan
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.5
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    • pp.961-987
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    • 2012
  • A compartment model of the flow driven by pumping without valves (valveless pumping) in an open tank system is proposed. By the open tank system, we mean that two rigid cylindrical tanks are connected with an elastic tube. An incompressible fluid fills this system up to a certain level in tanks under the gravity. The compartment model for analyzing such open system is derived from the energy principle which will be called the energy conserving compartment model or shortly the ECCM. Based on this ECCM of valveless pumping, we explore the occurrence of directional net flow or directional net power by a specific excitation at an asymmetric part of the elastic tube. The interaction between deformable elastic tube and the fluid inside is considered in the ECCM. The reliability of the ECCMis investigated through some physical examples. The ECCM shows the existence of directional net power of the valveless pump system with open tanks and confirms that the direction and magnitude of the net power depend on the pumping frequency as well. Furthermore, the phase synchronization in time between the fluid pressure difference and the external pinching force over the pumping region is highly related to the direction of energy storing or net power.

A Study of Geothermal Power Production with Flashed Steam System (플래쉬 시스템에 의한 지열 발전 성능해석)

  • Lee, Se-Kyoun;Woo, Joung-Son
    • Journal of the Korean Solar Energy Society
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    • v.28 no.5
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    • pp.1-7
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    • 2008
  • Flashed steam system is one of the important geothermal power production methods. In this paper, optimum operations and performances of single and double flash systems are presented. It is shown that double flash system can produce about 26.5% more power than single flash system. Temperature of geothermal water($T_R$) is the most important parameter in the geothermal system. Optimum single and double flash temperatures and net power produced with these optimum conditions are expressed as a function of $T_R$ in this study. Thus net power output from geothermal resources can be estimated with the results of this work. Condenser Temperature($T_{con}$) is also important and the net power production can be shown as a function of ($T_R-T_{con}$. Volume flow rate per unit power is also to be considered as the condenser temperature decreases.

Development of the Automatic Hauling Operation System by Three boats for Anchovy Boat Seine (기선권현망어업의 3척식 자동화 양망시스템 개발)

  • An, Young-Su;Jang, Choong-Sik;Lee, Myeong-Kyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.2
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    • pp.147-155
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    • 2005
  • This study was conducted in order to improve the automatic fishing operation system for anchovy boat seine by comparison with the fishing gear geometry and efficiency using the labor saving nets and the combined type net with midwater trawl. Field experiments were carried out to observe the geometry of nets and improve the fishing operation system by catcher boats. The vertical net opening of fore wing net, square, fore bag net and after bag net of the combined type net were varied in the range of 9.9~12.9. 16.2~28.2, 6.8~12.1 and 9.5~15.2m respectively, when the towing speed was 1.0m/sec and the distance between boats were 100m, 200m, 300m. The vertical net opening of the combined type nets was gradually decreased as function of with increasing the distance between catcher boats. Labor saving net which was maintained the net opening and towing depth stable was more suitable for the automatic hauling operation system by improvement of bag net rather than the combined type nets which was impossible in swallow depth and near to anchovy school. 3 boats hauling operation system of the labor saving net was carried out by crane with power block in 2 catcher boats for improvement of hauling operation and pushing equipment of anchovy cooking system in the processing boat for maintain more anchovy in dry frame. From the results of field experiments, 3 boats hauling operation system with power block and improved cooking system was very 3 boats hauling operation system with power block and improved cooking system was very useful and more practical as hauling time 20~35min and No. of fishermen 12~13 in comparison with the traditional system such as hauling time 30~50 min and No. of fishmen 28~38.

Design of Unification of Power device of Stow-Net Fishing System -Unification of Power Device by Hydraulic Power- (안강망 어로 시스템 동력장치의 통합화 설계 -유압동력을 사용한 동력장치의 통합-)

  • 문덕홍
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.1
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    • pp.65-76
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    • 1999
  • Our status of off-shore stow-net fishery is in face with many difficult problems; the lack of fisherman by evading the 3-D occupation, the safety accident by unskilled crew and old type fishing system. In order to solve those problems, it is necessary to save the man power and ensure the safety of fishing work by the effective utilization of power and automatization of fishing gear system. This is consists of the side drum driven by main engine, the net hauler, the bow and stern capstan, jib crane etc. Therefore, we suggest the design on unification of power device of fishing gear system as follows; (1) fishing system by uni-hydraulic power and (2) fishing system by electric motor and electro-hydraulic power.

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Fault Diagnosis of a Refrigeration System Based on Petri Net Model (페트리네트 모델을 이용한 냉동시스템의 고장 진단)

  • Jeong, S.K.;Yoon, J.S.
    • Journal of Power System Engineering
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    • v.9 no.4
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    • pp.187-193
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    • 2005
  • In this paper, we proposes a man-machine interface design for fault diagnosis system with inter-node search method in a Petri net model. First, complicated fault cases are modeled as the Petri net graph expressions. Next, to find out causes of the faults on which we focus, a Petri net model is analyzed using the backward reasoning of transition-invariance in the Petri net. In this step, the inter-node search method algorithm is applied to the Petri net model for reducing the range of sources in faults. Finally, the proposed method is applied to a fault diagnosis of a refrigeration system to confirm the validity of the proposed method.

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A new lightweight network based on MobileNetV3

  • Zhao, Liquan;Wang, Leilei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.1
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    • pp.1-15
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    • 2022
  • The MobileNetV3 is specially designed for mobile devices with limited memory and computing power. To reduce the network parameters and improve the network inference speed, a new lightweight network is proposed based on MobileNetV3. Firstly, to reduce the computation of residual blocks, a partial residual structure is designed by dividing the input feature maps into two parts. The designed partial residual structure is used to replace the residual block in MobileNetV3. Secondly, a dual-path feature extraction structure is designed to further reduce the computation of MobileNetV3. Different convolution kernel sizes are used in the two paths to extract feature maps with different sizes. Besides, a transition layer is also designed for fusing features to reduce the influence of the new structure on accuracy. The CIFAR-100 dataset and Image Net dataset are used to test the performance of the proposed partial residual structure. The ResNet based on the proposed partial residual structure has smaller parameters and FLOPs than the original ResNet. The performance of improved MobileNetV3 is tested on CIFAR-10, CIFAR-100 and ImageNet image classification task dataset. Comparing MobileNetV3, GhostNet and MobileNetV2, the improved MobileNetV3 has smaller parameters and FLOPs. Besides, the improved MobileNetV3 is also tested on CPU and Raspberry Pi. It is faster than other networks

Fuzzy Petri-net Approach to Fault Diagnosis in Power Systems Using the Time Sequence Information of Protection System

  • Roh, Myong-Gyun;Hong, Sang-Eun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1727-1731
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    • 2003
  • In this paper we proposed backward fuzzy Petri-net to diagnoses faults in power systems by using the time sequence information of protection system. As the complexity of power systems increases, especially in the case of multiple faults or incorrect operation of protective devices, fault diagnosis requires new and systematic methods to the reasoning process, which improves both its accuracy and its efficiency. The fuzzy Petri-net models of protection system are composed of the operating process of protective devices and the fault diagnosis process. Fault diagnosis model, which makes use of the nature of fuzzy Petri-net, is developed to overcome the drawbacks of methods that depend on operator knowledge. The proposed method can reduce processing time and increase accuracy when compared with the traditional methods. And also this method covers online processing of real-time data from SCADA (Supervisory Control and Data Acquisition)

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Agent-based Colored Petri Net Modeling of Grid Information Flows : Modeling of Wide Area Protection System (에이전트 기반 컬러 페트리 넷을 이용한 전력 계통의 정보 흐름 모델링: 광역 보호 시스템에의 적용)

  • Park, Byung-Sung;Hur, Kyeon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.7
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    • pp.1347-1353
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    • 2011
  • While most of the existing protection schemes have been designed with local information around individual components, these local schemes are not considered capable of protecting the modern electric power gird with growing complexity. Recent blackouts in North America and Europe have renewed the emphasis on coordinated protection and control actions to avoid systemwide blackouts, utilizing all of the available grid information. Thus, this paper proposes a new methodology, Agent-based Colored Petri Net (ACPN) modeling for systematically representing, modeling and analyzing information flows and interactions among the entities of the electric power grid. The paper demonstrates its efficacy and accuracy by investigating an ACPN model of a wide area protection system for a typical power grid. The proposed modeling and analysis schemes may further provide a framework to help assure reliability and interoperability of diverse smart grid components.

A Study on the Analysis of the Performance and Efficiency of a Low-pressure Operating PEMFC System for Vehicle Applications Using MATLAB/Simulink (MATLAB/Simulink를 이용한 자동차용 상압형 PEM 연료전지 시스템의 성능 및 효율 분석 연구)

  • Park, Raehyeok;Kim, Han-Sang
    • Journal of Hydrogen and New Energy
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    • v.24 no.5
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    • pp.393-400
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    • 2013
  • The air supply system has a significant effect on the efficiency of polymer electrolyte membrane fuel cell (PEMFC) systems. The performance and efficiency of automotive PEMFC systems are greatly influenced by their air supply system configurations. This study deals with the system simulation of automotive PEMFC systems using MATLAB/Simulink framework. In this study, a low-pressure operating PEMFC system adopting blower sub-module (turbo-blower) is modeled to investigate the effects of stack operating temperature and air stoichiometry on the parasitic power and efficiency of automotive PEMFC systems. In addition, the PEMFC net system efficiency and parasitic power of air supply system are mainly compared for the two types (low-pressure operating and high-pressure operating) of automotive PEMFC systems under the same net power conditions. It is suggested that the obtained results from this system approach can be applied for establishing the novel operating strategies for FC vehicles.