Method and device for driving a turn-off thyristor
AssigneeAsea Brown Boveri AG
InventorsArd Coenraads, Horst Grüning
Life of this patent
Estimating the term…
Abstract
A method for turning a GTO on and off and a corresponding driving circuit are specified. A turn-on current and a holding current are generated from voltage pulses which are converted into currents with the aid of an electric energy store. In terms of circuitry, it is particularly advantageous when the required voltage pulses are drawn from the same energy source, or the same energy store, as the pulse required to generate the turn-off current. The holding current is preferably generated by repeating voltage pulses. The repetition frequency of said voltage pulses can then be increased or reduced as required. The frequency is reduced, in particular, when the gate-cathode voltage becomes negative, and is increased again when the voltage is positive again.
Claims10
A driving method for turning a turn-off thyristor having at least a gate terminal and a cathode terminal on and off, comprising the following steps:
- (a) generating a turn-off current for turning off the turn-off thyristor with the aid of a capacitive first energy store which is arranged between the gate terminal and the cathode terminal of the turn-off thyristor;
- (b) generating a turn-on current for turning on the turn-off thyristor;
- (c) generating a holding current for maintaining a turned-on state of the turn-off thyristor;
- wherein
- (d) the step of generating the turn-on current includes converting voltage pulses from the capacitive first energy store into a current with the aid of at least one second energy store and the step of generating the holding current includes converting a sequence of said voltage pulses having a variable repetition frequency f1 into a current with the aid of the at least one second energy store.
A driving circuit for turning a turn-off thyristor having at least a gate terminal and a cathode terminal on and off, the driving circuit comprising:
- a turn-off circuit including a capacitive first energy store which is arranged between the gate terminal and the cathode terminal of the turn-off thyristor and configured to generate a turn-off current from energy supplied by the capacitive first energy store and to apply the turn-off current by means of a first switch to the gate terminal of the turn-off thyristor;
- and
- a turn-on circuit arranged between the gate terminal and the cathode terminal of the turn-off thyristor and configured to generate a gate trigger current and a holding current which maintains a turned-on state of the turn-off thyristor, wherein the turn-on circuit comprises at least one second energy store configured to convert voltage pulses drawn from the capacitive first energy store, and fed to the at least one second energy store, into the gate trigger current and the holding current.
Dependencies are inferred from the claim text.