Abstract:
In a high tension thyristor current converter comprising a plurality of similarly designed sections in series with each other, each section including at least one main thyristor, a voltage divider and a control device, each such section is shunted by an auxiliary thyristor circuit dimensioned in such a way that the electric strains at the time of switching on and off the thyristors are reduced. In this case it is possible to delay the ignition or the main thyristor with respect to the ignition of the auxiliary thyristor, until the voltage across the main thyristor has declined to a value not endangering the ignition of said thyristor, and/or to delay the extinction of the auxiliary thyristor relative to the extinction of the main thyristor, so that the recovery time of the main thyristor will be determined by said auxiliary thyristor.
Abstract:
In order to improve the performance of series connected thyristors these are provided with an individual electrode connected to a n-layer or a p-layer nearest the anode respectively the cathode of each thyristor. A separate DC voltage source supplies this electrode with a voltage, called booster voltage, and is connected in such a circuit that the source in the case of a chain of a number of series connected thyristors serves simultaneously two adjacent thyristors in the chain.