Gas-insulated high-voltage switch
View Patent ↗A high-voltage switch includes a contact arrangement having two arcing contacts, one of which is supported displaceably against the action of a pretensioned spring. When the contact arrangement is closed, the free ends of the two arcing contacts are supported on one another. When the contact arrangement is opened, the two arcing contacts separate and during this process an arcing zone, accommodating compressed arc gas, is produced which is limited axially by free ends of the two arcing contacts and radially by an insulating nozzle toward the outside. To prevent the displaceably supported arcing contact from returning against the action of the pretensioned spring when a large short-circuit current is interrupted, the switch includes a piston/cylinder system functioning as a restoring device, which communicates with the arcing zone and which, with increasing pressure of the compressed arc gas produced in the arcing zone, generates a restoring force supporting the repelling force of the pretensioned spring.
1. A gas-insulated high-voltage switch comprising:
a contact arrangement which includes a first contact member and a second contact member, both of the first and second contact members being movable along an axis, each of the contact members respectively including an arcing contact;
a pretensioned spring; and
an insulating nozzle attached at the first contact member, wherein:
the arcing contact of the second contact member is supported axially displaceably against the pretensioned spring;
when the contact arrangement is closed, free ends of the two arcing contacts are configured to be supported on one another to form a contact force generated by the pretensioned spring;
the two arcing contacts, when the contact arrangement is opened, are configured to separate from one another, and while the contacts arrangements separate from one another, an arcing zone, which accommodates compressed arc gas, is produced which is delimited axially by the free ends of the two arcing contacts and radially by the insulating nozzle toward outside of the switch;
the second contact member includes a piston/cylinder system with a compression space constituting a restoring device which communicates with the arcing zone and which, with increasing pressure of the compressed arc gas produced in the arcing zone, is configured to generate a restoring force supporting the repelling force of the pretensioned spring; and
the arcing zone is connected to the compression space via an expansion space being annularly constructed around the arcing contact.
2. The switch as claimed in claim 1 ,
wherein the compression space is delimited by a first end face of a piston of the piston/cylinder system, and a second end face of the piston, facing away from the compression space is connected rigidly with the arcing contact, the arcing contact having a smaller diameter than the piston.
3. The switch as claimed in claim 2 , wherein the arcing contact of the second contact member is conducted through a wall section, which shields the second end face of the piston from the arc gas, of a contact carrier.
4. The switch as claimed in claim 3 , comprising:
a hollow cylinder of the piston/cylinder system is held at the wall section of the contact carrier,
wherein the hollow cylinder is configured to limit the compression space radially toward the outside.
5. The switch as claimed in claim 4 , comprising:
a piston rod, which is configured to limit the compression space radially toward the inside of the switch, and which is mounted at the first end face, which axially limits the compression space, and
an exhaust duct, which is conducted axially through the compression space, and which is molded into the arcing contact of the second contact member, the piston and the piston rod, which connects the arcing zone with an exhaust space of the switch.
6. The switch as claimed in claim 5 , wherein the piston rod is conducted axially displaceably through a bottom, which limits the compression space axially, of the hollow cylinder.
7. The switch as claimed in claim 6 , wherein the pretensioned spring is arranged in the compression space and is supported on the first end face with one end and on the cylinder bottom with the opposite end.
8. The switch as claimed in claim 1 , wherein the wall of the expansion space is formed radially toward the outside by a sleeve used as longitudinal guide of the insulating nozzle, held on the contact carrier, and radially toward the inside by the arcing contact of the second contact member, and
wherein the expansion space is connected to the arcing zone via an annular gap which is arranged between the insulating nozzle and the arcing contact of the second contact member, and communicates with the compression space via at least one duct which is conducted through the wall section of the contact carrier and the hollow cylinder.
9. The switch as claimed in claim 5 , wherein the arcing zone is connected to the compression space via an annularly constructed expansion space.
10. The switch as claimed in claim 9 , wherein the wall of the expansion space is formed radially toward the outside by a sleeve used as longitudinal guide of the insulating nozzle, held on the contact carrier, and radially toward the inside by the arcing contact of the second contact member, and
wherein the expansion space is connected to the arcing zone via an annular gap which is arranged between the insulating nozzle and the arcing contact of the second contact member, and communicates with the compression space via at least one duct which is conducted through the wall section of the contact carrier and the hollow cylinder.