Redundant triggering means for hvdc valve

Claim 2

In a high voltage electric valve comprising first and second serially connected switching matrices and first and second triggering means respectively associated therewith, each of said matrices comprising at least one thyristor, which conducts current therethrough when supplied with a trigger signal from the triggering means associated with its matrix, a main inductor connected in series with said thyristor, and an auxiliary inductor connected in series with resistance means to form a transient suppressing subcircuit connected in shunt with said main inductor, said first and second triggering means being normally operative in unison to provide simultaneous trigger signals for all of the thyristors of said matrices, the improvement comprising: first auxiliary triggering means magnetically coupled to the auxiliary inductor of said first matrix and operative in response to the commencement of current flowing therethrough for providing a triggering signal to the thyristor of said second matrix irrespective of whether or not the second triggering means is operating, and second auxiliary triggering means magnetically coupled to the auxiliary inductor of said second matrix and operative in response to the commencement of current flowing therethrough for providing a triggering signal to the thyristor of said first matrix irrespective of whether or not the first triggering means is operating.

Claim 3

In a high voltage electric valve comprising first and second serially connected switching matrices and first and second triggering means respectively associated therewith, each of said matrices comprising at least one thyristor, which conducts current therethrough when supplied with a trigger signal from the triggering means associated with its matrix, and means for initially limiting inrush current through said thyristor when it begins conducting, said triggering means being normally operative in unison to provide simultaneous trigger signals for all of the thyristors of said matrices, the improvement comprising: first auxiliary triggering means associated with the current limiting means of said first matrix and operative in response to the commencement of current flowing therethrough, for providing a triggering signal to the thyristor of said second matrix irrespective of whether or not the second triggering means is operating, and second auxiliary triggering means associated with the current limiting means of said second matrix and operative in response to the commencement of current flowing therethrough for providing a triggering signal to the thyristor of the first matrix irrespective of whether or not the first triggering means is operating, each of said first and second auxiliary triggering means comprising energy storage means, means for supplying energy to said energy storing means from the current flowing through the associated current limiting means, and means operative when a preselected amount of energy has been stored in said storage means for rapidly releasing said energy to provide said triggering signals.

Claim 4

In a high voltage electric valve comprising first and second serially connected switching matrices and first and second triggering means respectively associated therewith, each of said matrices comprising at least one thyristor, which conducts current therethrough when supplied with a trigger signal from the triggering means associated with its matrix, and means for initially limiting inrush current through said thyristor when it begins conducting, said triggering means being normally operative in unison to provide simultaneous trigger signals for all of the thyristors of said matrices, the improvement comprising: first auxiliary triggering means associated with the current limiting means of said first matrix and operative in response to the commencement of current flowing therethrough, for providing a triggering signal to the thyristor of said second matrix irrespective of whether or not the second triggering means is operating, and second auxiliary triggering means associated with the current limiting means of said second matrix and operative in response to the commencement of current flowing therethrough for providing a triggering signal to the thyristor of the first matrix irrespective of whether or not the first triggering means is operating, each of said first and second auxiliary triggering means comprising energy storage means, means for supplying energy to said energy storing means from the current flowing through the associated current limiting means, and means operative when a preselected amount of energy has been stored in said storage means for rapidly releasing said energy to provide said triggering signals.

Claim 5

The electric valve as specified in claim 2 wherein said energy storage means comprises a capacitor and wherein said last mentioned means comprises a four layer diode.