for the protection of gas-insulated metal-enclosed switchgear against lightning and switching overvoltages

Transcription

1 GAS-INSULATED METAL-ENCLOSED SURGE ARRESTERS (GIS-ARRESTERS) for the protection of gas-insulated metal-enclosed switchgear against lightning and switching overvoltages

2 GIS-Arresters from Siemens GIS arresters Type 3EP2 1-3PKZ for the protection of a gas insulated 123--switch-gear Type 8DN9 (Resonant earthed system, TEAG Jena, Germany) Siemens gas-insulated, metal-enclosed arresters (GIS arresters) provide optimum protection for gas-insulated switchgear (GIS). Two reasons are decisive here. On the one hand, GIS arresters can be installed very close to the object to be protected. This is important for instance when GIS are fed by long cables. Overvoltages, which can be caused by travelling wave occurrences, are limited very effectively in this way. On the other hand, the low self-inductance of GIS arresters provides the best conceivable protection against high rate-of-rise voltages, which are particularly critical for gas-insulated equipment. The first Siemens GIS arresters have been supplied in 197. Since then, they have been designed for an extremely wide range of applications and have been installed worldwide. Today, Siemens possesses extensive know-how concerning GIS arresters, assuring optimum operating properties and the highest possible reliability. Siemens supplies two different series of GIS arresters. In the case of the 3EP2-K type range, the resistors are electrically and mechanically of single-column construction. These arresters are available as single (i.e. one phase per vessel) or three-phase (i.e. three phases per vessel) types. In contrast, the 3EP3-K type range incorporates resistors which are mechanically of three-column while electrically of one-column design. This results in a meandering low-inductance current path and reduces the overall length of the arresters. Common to both type ranges is the fact that they are fitted with safety rupture diaphragms and of course comply with international regulations (e.g. IEC 17). By virtue of suitable choice of material and corresponding paint structure, the Siemens GIS arresters are generally suitable for outdoor installation. Every GIS arrester is fitted with a gas connection. This allows the arrester to be incorporated in an existing gas monitoring system; it is also possible, however, to provide a separate arrester gas monitor. The earth-side end of each individual arrester phase is led out of its tank through an insulated bushing, to which monitoring devices, such as surge counters, spark gaps or leakage current meters can be connected. GIS arresters Type 3EP3 378-PKZ at the transformers in a gas insulated --switch-gear Type 8DQ1 (BEWAG Berlin, Germany)

3 >10 i peak ma Type 3EP2...-3PK (Diameter 392 mm) Nominal system voltage Highest voltage for equipment U m up to 10 up to 170 SF -SF -bushing (SF -Oil-bushing on request) Spring contact Access cover with pressure relief device and filter Enclosure Grading hood Metal-oxide resistors Supporting rods Electrical monitoring devices Gas pressure/density monitoring Arrester Data Height Total weight (max.) Maximum rated voltage U r Maximum nominal discharge current acc. to IEC 99- Maximum classifying current acc. to ANSI/IEEE C2.11 Maximum line discharge class Maximum energy absorbing capability Maximum long duration current impulse, 2 ms Short circuit rating 100 / 10 / / 300 / mm kg kj/ r A

4 >10 i peak ma Type 3EP2...-3PK3 (Diameter 710 mm, three-phase arrester) Nominal system voltage Highest voltage for equipment U m up to 10 up to 170 SF -SF -bushing (SF -Oil-bushing on request) Spring contact Enclosure Access cover with pressure relief device and filter Grading hood Metal-oxide resistors Supporting rods Electrical monitoring devices (each phase separate) Gas pressure/density monitoring Arrester Data Height Total weight (max.) Maximum rated voltage U r Maximum nominal discharge current acc. to IEC 99- Maximum classifying current acc. to ANSI/IEEE C2.11 Maximum line discharge class Maximum energy absorbing capability Maximum long duration current impulse, 2 ms Short circuit rating mm kg kj/ r A

5 >10 i peak ma Type 3EP3...-PK (Diameter 710 mm) Nominal system voltage Highest voltage for equipment U m SF -SF -bushing (SF -Oil-bushing on request) Access cover with pressure relief device and filter Spring contact Enclosure Grading hood Metal-oxide resistors Supporting tube Electrical monitoring devices Gas pressure/density monitoring Arrester Data Height Total weight (max.) Maximum rated voltage U r Nominal discharge current acc. to IEC 99- Maximum classifying current acc. to ANSI/IEEE C2.11 Maximum line discharge class Maximum energy absorbing capability Maximum long duration current impulse, 2 ms Short circuit rating 110 / / / mm kg kj/ r A

6 >10 i peak ma Type 3EP3...-PK (Diameter 900 mm) Nominal system voltage Highest voltage for equipment U m 380 / 00 / 0 SF -SF -bushing (SF -Oil-bushing on request) Access cover with pressure relief device and filter Spring contact Enclosure 2 Grading hood Metal-oxide resistors Supporting tube Gas pressure/density monitoring Electrical monitoring devices Arrester Data Height Total weight (max.) Maximum rated voltage U r Nominal discharge current acc. to IEC 99- Maximum classifying current acc. to ANSI/IEEE C2.11 Maximum line discharge class Maximum energy absorbing capability Maximum long duration current impulse, 2 ms Short circuit rating 211 / 0 10 / / mm kg kj/ r A

7 Optimal operating characteristics and maximal operational reliability Siemens GIS arresters permit versatile connection to any GIS system. Bushings may be of the standard type or customer specific. Gas-to-gas type bushings as well as gas-to oil type bushings for connection to transformers are available. In addition to the standard connection flanges, special flanges or additional adaptor flanges can also be designed, constructed and provided according to customer requirements. GIS arresters Type 3EP3 378-PKZ at the line entrance of a gas insulated --switch-gear Type 8DQ1 (BEWAG Berlin, Germany) Commissioning is possible with the absolute minimum of time and expense. The internal mechanical construction of the arresters has been optimized to the effect that no transport braces have to be removed on site. Opening of the tank, which is usually undesirable, is therefore not necessary. However, an internal disconnecting device is provided, which allows to perform dielectric tests on the GIS without removing the arrester. Installation of the GIS arresters is possible, according to customer requirements, either suspended, upright or horizontal. Siemens GIS arresters are virtually maintenance-free. Apart from the usual checking of possible electrical monitoring devices and the gas monitor, it is only necessary to check the gas humidity after ten years and to change the filter material present in the tank after twenty years of service.

8 For Further Information Please fax this page to the following number: Fax Siemens AG, EV HBA 1323 Berlin Germany Name Position Company/Department Street Town / Country Telephone / Telefax Power system data and requirements Nominal system voltage or highest voltage for equipment U m Earth fault factor (if known) δ <1. 1.< δ <1.7 δ = 3 Earth fault duration (if known) < 10 sec > 10 sec or type of neutral earthing Direct Low-resistance Arc-suppression coil (earth fault compensation) Nominal discharge current Line discharge class Connection to (GIS, transformer,...) Manufacturer / Type Seismic requirements Monitoring devices Any other data / information Power Transmission and Distribution Group High Voltage Division Arrester and Limiters Siemens AG, EV HBA D-1323 Berlin Power Transmission and Distribution Subject to change without prior notice Siemens Aktiengesellschaft 11.97