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Integrated Protection Unit Design for Power Networks
Zhan-feng Fan,Sheng-ming Ge,Z Q Bo,Lin Wang,Feng-quan Zhou,Xing Liu,Guo-bing Song 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4
This paper presents an hardware design solution for integrated protection of distribution systems (Network Protection Unit) by combining transient polarity comparison technique, which is based on the detection and processing of fault generated transient current signals. The integrated protection relays installed at each substation of a distribution network are communicated with the Network Protection Unit through specially designed Packet Transport Network (PTN) for fast and reliable transmission of transient polarity current signals. The relay detects the faulted generated super-imposed current signals. The transient polarity identification algorithm is then applied to the super-imposed signals to identify the polarity of the signal detected. The Network Protection Unit can collect all the transient polarity current signals under its protection area. Then The direction of a fault is determined by comparison of the polarity of the signals derived from all the line sections connected to the substation. The actual faulted section is identified by the Network Protection Unit through comparing the directional information from various stations. Simulation results presented in the paper demonstrate the feasibility of the scheme.
Thermal and mechanical properties of poly(latic acid) reinforced with silanized basalt scales
Shan-Shan Yao,Ming-Zhan Gao,Zhao-Yang Feng,Fan-Long Jin,박수진 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.7
Biodegradable poly(lactic acid) (PLA)-based composites were prepared using PLA and basalt scale (BS) viaa solution-blending method. BS surfaces were treated using a silane coupling agent, and their surface properties werecharacterized by high-resolution scanning electron microscopy, energy-dispersive X-ray spectrometry, and X-ray photoelectronspectrometry. Moreover, the influence of BS content on the thermal properties, flexural properties, impactstrength, and morphology of the PLA/silane-coupling-agent-treated BS (KH-BS) composites was analyzed. The thermalstability of the composites significantly increased due to the addition of KH-BS. Impact strength tests showed thatthe impact strength of the PLA/KH-BS composite with 4 wt% KH-BS was 3.14 kJ/m2, which is 51% higher than that ofpristine PLA (2.07 kJ/m2). The analysis of the fracture surfaces of the composites after the impact strength tests revealeda rough morphology with numerous river-like micro-cracks. The study results demonstrate that the addition of KH-BSsignificantly improves the thermal stability and impact strength of PLA/KH-BS composites.
Performance Analysis of Packet Transport Network Communication for Integrated Wide-Area Protection
Sheng-ming Ge,Z Q Bo,Lin Wang,Zhan-feng Fan,Xing Liu,Feng-quan Zhou 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.3
As a new protection, wide-area protection enables protective relaying, and automatic control based on electric power system network communications and comprehensive judgment of multi-point information, which plays an increasingly important role in the secure and stable operation of electric power system. Interaction of wide-area information relies on communication network featuring high reliability and low time delay. On the other hand, most service of power transformation station is gradually towards IP and data oriented, along with the development of smart grid. This paper aims to introduce the wide-area protection technology supported by Packet Transport Network (PTN) communication technology, with analyzing the QoS (Quality of Service) network assurance architecture of PTN network, which establishes three planes, including transport plane, management plane, and control plane, based on ASON (Automatically Switched Optical Network) technology. After demonstrating the QoS assurance system of PTN from traffic control and transmission route, this paper introduces PTN networking test. Based on detailed parameters in the test results, the transmission performance of PTN on time delay, protection, and time synchronization of various electric power communication services are analyzed, with showing that PTN can fully meet the requirements of electric power communication.