Presentation is loading. Please wait.

Presentation is loading. Please wait.

Medium-Voltage Switchgear - Then and Now -

Similar presentations

Presentation on theme: "Medium-Voltage Switchgear - Then and Now -"— Presentation transcript:

1 Medium-Voltage Switchgear - Then and Now -
Hans-Joachim Müller

2 Evolution of Medium-Voltage Switchgear
Source: ABB Local installation Workshop manufacture Factory-assembled, type-tested Factory-assembled, compact Factory-assembled, SF6-insulated non type tested type tested Air-insulated Air/solid-insulated Cast-resin insulated Gas-insulated Year until 1950 until 1970 since 1970 since 1980 since 1982 Building 83 m3 47 m3 29 m3 24 m3 8 m3 Panel 19 m3 14.5 m3 8.7 m3 5.8 m3 2.2 m3

3 Situation in the Past Yesterday, switchgear were air, oil or cast-resin insulated with the following features: Huge dimensions Dependent on pollution and climate Maintenance at regular intervals Human failure during maintenance High fire risk Not arc-fault tested This means: High investment for buildings High costs for maintenance staff and system transfer in the network Breakdown of the network (longer downtimes)

4 Restricted Availability and Reliability of Supply
After short circuit at the rear side of an epoxy-resin insulated switchgear Burned-out 10 kV substation: Fire after short circuit in an epoxy-resin insulated ring-main unit

5 Objectives for the Development of New Switchgear
Requirements for development: Personal safety Reliability of supply Maintenance-free design Suitability for all switching duties Sufficient power reserves Low fire risk Small, light design Concept options for new switchgear due to availability of the following equipment: Maintenance-free switching devices Shockproof cable plugs and bar connections Electronic measuring and protection devices

6 Implementation of the Development Tasks
Constructional implementation: Solid insulation is replaced by insulating gas with constant properties Sealed enclosure of primary part Installation of fixed-mounted, maintenance-free switching devices: - Vacuum circuit-breaker - Three-position switch - SF6-switch-disconnector Shockproof cable plugs Use of current and voltage transformers with low susceptibility to faults Verification of safe isolation from supply with capacitive voltage dividers Maintenance-free and reliable operating elements with few parts inside the enclosure Easiest operation Pressure-resistant enclosure with defined pressure relief

7 Situation with Gas-Insulated Switchgear
Today’s state of the art is gas-insulated switchgear with the following main benefits: Small, compact dimensions Independent of environmental effects and climate Widely maintenance-free Maximum safety for staff Low fire risk Arc-fault tested Advantages: Low invest for buildings due to compact dimensions and climate-independent design Maximized power supply reliability Maximum personal safety Lowest life cycle costs Reduced operational costs - no additional maintenance costs

8 First SIEMENS Gas-Insulated Medium-Voltage Switchgear (April 1982)
Kulmbach / Germany 8DA10 16 panels 24 kV / 16 kA (3s) / 1250 A

9 Applications Today Tibet / China 8DA10 205 panels
40.5 kV / 31.5 kA (3s) / 1250 A Site altitude: 3000 – 5000 m

10 First SIEMENS Gas-Insulated Medium-Voltage Ring-Main Unit (April 1982)
Stadtwerke Lambrecht / Pfalz, Germany Project: Municipal power supply Electrical data: 24 kV, 16 kA, 630 A Typicals: 8DJ10, scheme 10

11 Switchgear Type 8DJ Typical Application Examples

12 Thank you very much for your attention!

Download ppt "Medium-Voltage Switchgear - Then and Now -"

Similar presentations

Ads by Google