Surges and Ground Fault Characteristics Analysis for CCS of Transmission System and Ground Protective Relay Setting Review
| Autor: | Jie-Jhen Liou, 劉劼臻 |
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| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 Cable connect station (CCS) of transmission system is the junction of overhead lines and underground cables. The system frameworks and line parameters are discontinue at CCS, which let the electrical faults to happen easily. This article is to analyze the lightning surges, switching surges and ground fault characteristics and to assess the impact of CCS. Moreover, CCS often located public accessible place. Once the potential distribution caused by ground faults will generate step voltage and touch voltage. The safety of the public have concerns, must be analyzed. To assess the impact on the safety of personnel and review the ground fault protective relay setting is appropriate. First of all, system modeling and analysis are based on the alternative program (ATP) of electromagnetic transient program (EMTP). The system model will cover extra-high voltage substation (E/S) and distribution substation (D/S). Transmission line is 161kV double-circuit transmission, including overhead lines, underground cables and CCS. Lightning and switching surges analysis observation CCS of cable phase voltage and ground potential rise (GPR), and to assess its impact on arresters. Ground fault analyzes GPR and current of grounding system. Based on the simulation results, a software package for grounding system analysis, named current distribution electromagnetic ground and soil structure analysis (CDEGS), is used to simulate step voltage and touch voltage of CCS. And to assess the impact on the safety of personnel. To ensure the safety of personnel, we will consider different laying conditions of CCS. Review the protective relay settings and take relevant measures in order to ensure safety of system and personnel. The results showed that structure of 12 in the lightning, switching surges and ground fault, can effectively improve the CCS GPR, step voltage and touch voltage. Moreover, when arrester struck by lightning and switching surges, there is the risk of damage, we recommend using a higher level of arrester. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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