Presentation on theme: "Cigré/Brasil CE B5 – Proteção e Automação Seminário Interno de Preparação para o Colóquio de Madri 2007 Rio de Janeiro, outubro/07."— Presentation transcript:
Cigré/Brasil CE B5 – Proteção e Automação Seminário Interno de Preparação para o Colóquio de Madri 2007 Rio de Janeiro, outubro/07
Dados do Artigo Número111 TítuloVerification of Utility Requirements on Modern Numerical Busbar Protection by Dynamic Simulation AutoriaZoran Gajic, JP Wang, PW Gong, YS Xu, ZX Zhou PaísSweden, China
Objetivo This paper presents a set of requirements posed on busbar protection by Chinese transmission system operator. In order to approve a busbar differential relay to be used in the Chinese transmission grid its performance must be verified by the national testing institute. Test setup and actual test results for one particular implementation of a modern numerical busbar protection are presented. Performance of the busbar protection relay is verified on an analogue power system simulator for different operating conditions for the busbar protection scheme such as external faults with and without CT saturation, internal faults, evolving faults, faults during power swing, etc.
Destaques The numerical busbar protection has been tested on an analogue power system simulator in order to verify that it can handle both station configurations. Different operating conditions for the busbar protections have been tested as listed below: Internal and external metallic faults (i.e. without fault resistance) Internal faults with fault resistance Evolving faults Circuit Breaker Failure Power swing and faults during power swing Internal and external faults during active load-transfer for double-bus single-breaker station CT saturation for external faults Open CT secondary circuits Line and power transformer energization Internal and external faults during off-nominal power system frequency condition Special test for one-and-a-half breaker station (internal faults with out-feed currents) DC power switching (off/on) while relay is in service and busbar is loaded Faults during off-nominal frequency conditions Internal and external metallic faults (i.e. without fault resistance) Altogether 1528 test cases on an analogue power system simulator were performed
Dúvidas Double-bus single –breaker station layout Four feeder bays and one bus-coupler One-and-a-half-breaker Two full diameters Why these busbar configuration? Are them pre defined by CEPRI?
Conclusões After all these tests, the protection relay was officially approved by CEPRI to be used for busbar protection applications in China for all voltage levels up to and including 500kV
Respostas às questões do REP Número da questão Questão5 What are the main conditions to select one of the two available types of busbar protection arrangements? What are the operational experiences with one or another arrangement? Is there any differences regarding engineering, installation, testing, commissioning and operation of these two types of busbar protection arrangements? How is the DC power supply arranged for these two solutions? Resposta:Basically the main condition to choose one of the available arrangements (centralized or decentralized) is the cost of the cables to be installed in the relay room. New stations have a better cost benefit using decentralized busbar protection. Existing stations have a better cost benefit with centralized type.
Respostas às questões do REP Número da questão Questão11 What are the practical experiences from the factory acceptance testing and commissioning of numerical busbar protections? Is it easier to perform commissioning of (live) stations with numerical busbar protections then stations with the busbar protection using conventional technology? Resposta:Live stations commissioning are easily done with numerical busbar protection, as we can isolated bays and test each one individually without compromising energised bays while testing others. Also image replica of disconnectors can be simulated making tests easier
Respostas às questões do REP Número da questão Questão12 How is the disconnector replica tested for numerical busbar protection relays? Resposta:In cold commissioning they are tested checking real conditions. On live station they can be tested by simulation and checking the digital inputs status. This can be helpful to test specific bays at a time
Respostas às questões do REP Número da questão Questão13 What are the main utility considerations when deciding to perform approval testing of a busbar protection? When such tests are considered necessary? How is the issue of busbar protection relay software version handled in such approvals? Resposta:Not always dynamic tests are used to approval busbar protection. Most of times they are used when utility is using the busbar protection for the first time and have no experience with it. Software version are normally by specification granted to last version. Manufacturer has to delivery last version up end of warranty
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