8DQ1 up to 550 kV
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8DQ1 up to 550 kV
Gas Insulated Switchgear
The Siemens 8D range of gas-insulated switchgear (GIS), for rated voltages from 72.5 kV up to 550 kV, is an extremely successful product concept.
Since its introduction back in 1968, Siemens has installed more than 34,500 bays worldwide in all climatic zones of the earth. More than 420,000 years of bay operation have been recorded since. The experience gained from over 45 years with SF6 technology together with continuous development based on the latest research findings, assures demand-oriented technology and the highest possible level of quality and cost-effectiveness. All requirements, which are nowadays usually specified for modern and advanced switchgear with respect to performance and reliabiliy, are met by Siemens-switchgear.
Cost-effectiveness, reliability and customer support are the distinctive features of Siemens gas-insulated switchgear for rated voltages from 72.5 kV up to 800 kV.
Their compact design allows their use in the most confined spaces, whether in the basement of a high-rise building, in a department store, in an industrial plant, on the first floor of an old historic building or in a mobile container. The modular structure of the switchgear permits flexible designs and problem-free extension.
Siemens' gas-insulated metal-encapsulated switchgear, a world leader in terms of:
In addition to gas-insulated switchgear, we also supply gas-insulated transmission lines (GIL) for transmitting high capacities of power over long distances.
With the intelligent control and monitoring solution SICAM, Siemens has created a new system of hard- and software components for the automation of switchgear in the field of electrical energy supply.
The flexible protection and control system offers a sequence of new functions:
Partial discharge monitoring increases the reliability of high-voltage switchgears. It enables any changes in the insulation to be detected at an early stage during normal operation so that appropriate remedial action can be taken. Maintenance measures can thus be controlled according to requirements, thereby reducing operating costs. The measurement data is displayed and archived in the control room. With the aid of an expert system the user can produce trend forecasts from long-term archive data so that potential faults can be eliminated at an early stage. Thanks to the built-in self-monitoring, the system can also be used in unmanned substations.
The PD monitoring system is a sophisticated measuring system, by means of which it is possible to monitor internal partial discharges in gas-insulated switchgear (GIS).
It comprises a number of components:
1 SF6 gas-insulated metal-enclosed switchgear
2 Coupler : act as UHF antennas, integrated in the GIS at a number of points
3 PD converter box (node) : Measuring device, connected to the PD couplers of the three phases of a point of installation
4 Optical-fibre bus system : Device for data transmission between the measuring points and the contral processor unit
5 Central processor unit : Monitoring of the data stream from up to 90 measuring points
6 Operator unit : PC for visualisation, archiving and automatic interpretation of the measured data
Modem : for remote operation and data telecommunication
Gas-Insulated High-voltage Switchgear
Siemens supplied in 1976 the first gas-insulated substation for a rated voltage of 420 kV. A permanent process of improvement has led to today’s 8DQ1, suitable for a voltage range of up to 550 kV.
With the 8DQ1 system, a new generation of gas-insulated switchgear is available on the market, notable for its wide range of applications.
A fundamental feature of Siemens gas-insulated switchgear is the high degree of versatility provided by a modular design. With a remarkably small variety of active and passive modules, it is possible to meet all customary bus schemes.
The 8DQ1 with its single-phase encapsulated design minimizes dielectric and dynamic stresses.
The Siemens 8DQ1 belongs to the world leading gas-insulated switchgears.
|Rated voltage||up to||420 kV||420 kV||550 kV|
|Rated frequency||50/60 Hz||50/60 Hz||50/60 Hz|
|Rated short-duration power-frequency |
withstand voltage (1 min)
|up to||650 kV||650 kV||740 kV|
|Rated lightning impulse withstand |
voltage (1.2/50 µs)
|up to||1425 kV||1425 kV||1550 kV|
|Rated switching impulse withstand |
voltage (250 / 2500 µs)
|up to||1050 kV||1050 kV||1175 kV|
|Rated normal current - busbar||up to||5000 A||6300 A||5000 A|
|Rated normal current - feeder||up to||5000 A||5000 A||5000 A|
|Rated short circuit-breaking current||up to||63 kA|
(< 2 cycles)
(< 2 cycles)
|63 kA |
(< 2 cycles)
|Rated peak withstand current||up to||170 kA||216 kA||170 kA|
|Rated short-time withstand current|
(up to 3 s)
|up to||63 kA||80 kA||63 kA|
|Leakage rate per year and gas |
|< 0.1 %||< 0.1 %||< 0.1 %|
|Driving mechanism of circuit breaker||stored-energy spring (single pole drive)||stored-energy spring (single pole drive)||stored-energy spring (single pole drive)|
|Bay width||2200 mm||3600 mm||3600 mm|
|Ambient temperature range||-30 °C up to |
|-30 °C up to |
|-25 °C up to |
|Standards||IEC / IEEE / GOST||IEC / IEEE / GOST||IEC / IEEE / GOST|
Other values on request
Customer Support Center
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