Gas-insulated switchgear up to 145 kV, 40 kA, 3150 A type series 8DN8

Connecting environment-friendly wind energy to the grid with compact 8DN8 GIS in switchgear building Bay control systems in ergonomically arranged local control cabinet 8DN8 switchgear up to 145 kV, outgoing cable bay Benefiting from experience Our 8D series of gas-insulated switchgear represents a highly successful product concept. Since its introduction in 1968, Siemens has installed more than 24,000 bays worldwide. A total of well over 285,000 years of bay operation have since been recorded. Intensive research work, many years of system experience, and continuous further development of the...

Continuous further development has reduced the footprint required for 145-kV GIS to only 25% of the first designs in 1968 Our type series 8DN8 switchgear for all voltage levels from 72.5 kV to 145 kV represents one of the most compact systems of its kind available worldwide, and meets all of today’s requirements for modern, pioneering switchgear in terms of efficiency and economy. Its space-saving design and its low weight help make this switchgear extremely economical. Since the levels of noise and field emission (EMC) are extremely low, it is possible to easily integrate 8DN8 switchgear even...

The 8DN8 allows a high degree of versatility in The innovative design of the cast resin bushings allows switchgear layout thanks to its modular construction maximum flexibility in the design of bays and for installation A fundamental feature of our gas-insulated switchgear is the high degree of versatility made possible by its modular system. Depending on their respective functions, the components are housed either individually and/or combined in pressure-resistant, gas-tight enclosures. With a remarkably small number of active and passive modules, all customary bus schemes are possible. Standard...

Three-phase enclosure allows compact design: 8ND8 145 kV, cable bay with double busbar ,hVH i' ti—© 1. Integrated local control cubicle 2. Support for control cubicle 3. Current transformer 4. Busbar II with disconnector and earthing switch 5. Interrupter unit of the circuit-breaker 6. Busbar I with disconnector and earthing switch 7. Stored-energy spring mechanism with circuit-breaker control unit 8. Voltage transformer 9. High-speed earthing switch 10. Outgoing feeder module with disconnector and earthing switch 11. Cable sealing end Variations are possible with switchgear type series 72.5...

Circuit-breaker module The central element of the gas-insulated switchgear is the three-pole encapsulated circuit breaker comprising the following two main components: interrupter unit operating mechanism The design of the interrupter unit and of the storedenergy spring mechanism is based on proven and in most cases identical designs which have often been used for outdoor switchgear installations worldwide. Circuit-breaker module The stored-energy spring mechanism provides the force for opening and closing the circuit-breaker. It is installed in a compact corrosion-free aluminum housing. The...

Arc-quenching principle Interrupter unit The interrupter unit used in the circuit-breaker for arc quenching operates on the proven self-compression principle. Since this requires only minimal operating energy the mechanical stresses involved are low. Stressing of both the circuit-breaker and the housing is reduced. The current path In the case of a self-compression circuit-breaker, the current path is formed by the contact support (1), the base (6), and the moving contact cylinder (5). In the closed position, the operating current flows through the contact finger (3) and the arcing contact (4)...

Three-position switching device Schematic diagram Neutral position Disconnector closed Earthing switch closed The functions of a disconnecting switch and an earthing switch are combined in a three-position switching device. The moving contact either closes the gap or connects the high-voltage conductor to the mating contact of the earthing switch. Integral mutual interlocking of the two functions is achieved as a result of this design, thus eliminating the need for providing corresponding electrical interlocking. An insulated connection to the mating contact of the earthing switch is provided...

High-speed earthing switch The high-speed earthing switch used is of the socalled “pin-type.” In this type of switch, the earthing pin at earth potential is pushed into the tulip-shaped mating contact. The earthing switch is equipped with a spring-operated mechanism, charged by an electric motor. High-speed earthing switch Instrument transformers Current and voltage transformers are used for measuring, protection, and monitoring purposes and can be integrated at any point within the substation. The secondary connections are led out of the enclosure through gas-tight bushings and brought into...

Connection modules Connection modules join system components within a bay. They are also used for pipework penetrations and form the connection between switchgear components situated far apart. They also provide a means of connecting equipment such as transformers or overhead lines located some distance away. Both single-pole and three-pole encapsulated connection modules are available depending on the circuit and the spatial layout of the bay. Three-pole extension module Single-pole extension module Extension modules Extension modules connect switchgear components that are a long way away from...

Termination modules The termination modules connect the bays of the gas-insulated switchgear to the following items of equipment: overhead line transformer or reactor Example: cable termination (plug-in type) cable They thus form the transition between the SF6 gas insulation within the enclosure and other insulating media. Cable termination This three-pole module links the metal-enclosed gasinsulated switchgear with the high-voltage cables. All customary types of high-voltage cables can be connected without problem via conventional cable sealing ends or plug-in types. The primary conductor between...