Metal clad switch plants for high voltages with obturating means for preventing destructive pressure rise

Claim 2

A switch plant for high voltage electrical systems comprising, in combination; a closed metal envelope adapted to be connected to earth; means dividing said envelope into a number of compartments separated from each in gastight manner; means for supplying pressurized insulating gas to said compartments; a high-voltage electrical system enclosed within said envelope and including a bus bar in one of said compartments, a cable in another of said compartments and which is accessible for external electrical connections, circuit breaker means in a further compartment and connected to said cable, and a bus bar isolating switch selectively connecting said circuit breaker to said bus bar; said compartments being of different volumes which are smaller and greater than a predetermined volume which is sufficient to prevent destructive pressure rise of said insulating gas in the event of a serious electrical disturbance, passage means connecting each compartment having a volume less than said predetermined volume with another compartment having a volume with which it additively is at least equal to said predetermined volume, said passage means being of a crosssectional area sufficient to prevent said destructive pressure rise of said insulating gas in the event of a serious electrical disturbance in said compartment having a volume less than said predetermined volume; and obturating means in said passage means for minimizing the crosssectional area of said passage means during ordinary operation of the switch plant and fully to open said passage means at the occurrence of extraordinary conditions.

Claim 3

A switch plant as defined in claim 1, wherein said obturating means is in the form of a rupturable diaphragm.

Claim 4

The switch plant as defined in claim 2, wherein said diaphragm is provided with a relatively small aperture.

Claim 5

A switch plant for handling high voltages comprising, in combination; a closed metal envelope adapted to be electrically grounded and including at least a pair of conduit portions, a housing portion, and spaced pairs of closure means, each pair of closure means defining a secondary compartment therebetween separating the interior of said housing portion from the interior of a corresponding conduit portion and thereby defining separate compartments in said housing and conduit portions, said secondary compartments being of volumes insufficient to prevent destructive pressure rise of insulating gas therein due to serious electrical disturbance in such secondary compartments whereas that compartment defined by said housing is of sufficient volume to prevent such destructive pressure rise; a bus bar in one of said conduit portions and a cable in the other of said conduit portions; circuit breaker means in said compartment defined by said housing; a switch in that secondary compartment between said one conduit portion and said housing portIon and including separable contacts; conductors connecting the separable contacts of said switch respectively to said bus bar and to said circuit breaker means; conductor means connecting said circuit breaker means to said cable and extending through that secondary compartment between said housing portion and said other conduit portion; means supplying pressurized insulating gas to said separate compartments defined by said housing and conduit portions for maintaining substantially equal insulating gas pressure therein; and bypass means connecting each secondary compartment to said compartment defined by said housing for allowing substantially unrestricted flow of insulating gas from each secondary compartment to said compartment defined by said housing in response to sudden pressure increase in such secondary compartment which may be due to a malfunction within such secondary compartment.

Claim 6

A switch plant for handling high voltages comprising, in combination; a closed metal envelope adapted to be electrically grounded and including at least a pair of conduit portions, a housing portion, and spaced pairs of closure means, each pair of closure means defining a secondary compartment therebetween separating the interior of said housing portion from the interior of a corresponding conduit portion and thereby defining separate compartments in said housing and conduit portions, said secondary compartments being of volumes insufficient to prevent destructive pressure rise of insulating gas therein due to serious electrical disturbance in such secondary compartments whereas that compartment defined by said housing is of sufficient volume to prevent such destructive pressure rise; a bus bar in one of said conduit portions and a cable in the other of said conduit portions; circuit breaker means in said compartment defined by said housing; a switch in that secondary compartment between said one conduit portion and said housing portIon and including separable contacts; conductors connecting the separable contacts of said switch respectively to said bus bar and to said circuit breaker means; conductor means connecting said circuit breaker means to said cable and extending through that secondary compartment between said housing portion and said other conduit portion; means supplying pressurized insulating gas to said separate compartments defined by said housing and conduit portions for maintaining substantially equal insulating gas pressure therein; and bypass means connecting each secondary compartment to said compartment defined by said housing for allowing substantially unrestricted flow of insulating gas from each secondary compartment to said compartment defined by said housing in response to sudden pressure increase in such secondary compartment which may be due to a malfunction within such secondary compartment.

Claim 7

A switch plant as defined in claim 4, wherein one closure means of that pair thereof separating said housing from said one conduit portion is movable between operative and inoperative positions, and the bypass means associated therewith includes a conduit and a valve operable between closed and open positions in response to movement of said one closure means between its inoperative and operative positions.

Claim 8

A switch plant as defined in claim 5, wherein the bypass means associated with that secondary compartment separating said other conduit portion from said housing is in the form of a conduit having a rupturable diaphragm therein.

Claim 9

A switch plant as defined in claim 6, wherein said rupturable diaphragm is provided with a relatively small aperture.

Claim 10

A switch plant as defined in claim 4, wherein the bypass means associated with that secondary compartment separating said other conduit portion from said housing is in the form of a conduit having a rupturable diaphragm therein.

Claim 11

A switch plant as defined in claim 8, wherein said rupturable diaphragm is provided with a relatively small aperture.

Claim 12

A metal clad switch plant for high voltages comprising a closed metal envelope intended for connection to earth; said envelope being divided into a number of individual compartments having volumes which are smaller and bigger than a predetermined volume V, respectively, in which said volume V is just sufficient to prevent destructive pressure rise of insulating gas due to a serious electrical disturbance within a compartment; switches, terminal members for the connection of cables to the switch plant, devices for measurement and protection, and connecting conductors; said switches, terminal members, devices and conductors being insulatedly mounted in compartments of the envelope and constituting feed and delivery circuits of the switch plant; bus bars insulatedly mounted in compartments of the envelope and interconnecting said circuits; conduits for the supply of compressed insulating gas; each compartment of the envelope being in open communication with such a gas supply conduit; relatively wide connecting passages and obturating devices provided in said passages; each one of said passages extending between a compartment, of which the volume is smaller than the predetermined volume V, and another compartment, of which the volume makes together with that of the former compartment a volume which is at least equal to the volume V; and each obturating device being adapted to keep, at ordinary operation of the switch plant, the passage area of the relative connecting passage at a minimum and to open said passage to its full extent at the occurrence of extraordinary conditions.

Claim 13

A metal clad switch plant for high voltages comprising a closed metal envelope intended for connection to earth; said envelope being divided into a number of individual compartments having volumes which are smaller and bigger than a predetermined volume V, respectively, in which said volume V is just sufficient to prevent destructive pressure rise of insulating gas due to a serious electrical disturbance within a compartment; switches, terminal members for the connection of cables to the switch plant, devices for measurement and protection, and connecting conductors; said switches, terminal members, devices and conductors being insulatedly mounted in compartments of the envelope and constituting feed and delivery circuits of the switch plant; bus bars insulatedly mounted in compartments of the envelope and interconnecting said circuits; conduits for the supply of compressed insulating gas; each compartment of the envelope being in open communication with such a gas supply conduit; relatively wide connecting passages and obturating devices provided in said passages; each one of said passages extending between a compartment, of which the volume is smaller than the predetermined volume V, and another compartment, of which the volume makes together with that of the former compartment a volume which is at least equal to the volume V; and each obturating device being adapted to keep, at ordinary operation of the switch plant, the passage area of the relative connecting passage at a minimum and to open said passage to its full extent at the occurrence of extraordinary conditions.

Claim 14

A metal clad switch plant as claimed in claim 10, in which the obturating device is a rupturable diaphragm.

Claim 15

A metal clad switch plant as claimed in claim 11, in which the obturating device is a rupturable diaphragm provided with a relatively small aperture.

Claim 16

A metal clad switch plant as claimed in claim 10, including isolator switches forming part of the feed and delivery circuits of the switch plant, each isolator switch including a fixed contact permanently connected to one part of the relative circuit and a movable contact permanently connected to another part of said circuit; each isolator switch being accommodated in a compartment which is separated from at least one other compartment; movable partition walls which are each adapted to be moved into and out of an isolator switch compartment and to divide the relative isolator switch compartment into two chambers, when the relative isolator switch is in its open condition; the chamber confined between said other compartment and the partition wall being connected by a connecting passage provided with an obturating device to said other compartment and coupling means provided between said partition wall and said obturating device; said coupling means being adapted to close said obturating device, when the partition wall is moved out of the isolator switch compartment, and to open said obturating device when the partition wall is moved into the isolator switch compartment.

Claim 17

A metal clad switch plant as claimed in claim 13, in which a second connecting passage is provided between the chamber forming part of the isolator switch compartment and confined between said other compartment and said partition wall on one hand and said other compartment on the other hand; and a rupturable diaphragm in said second connecting passage.