Method for protecting the gate unit for a GTO thyristor

摘要

A method for protecting the gate unit for a GTO thyristor includes predetermining a characteristic curve as a time function adapted both to the maximum load capacity possible for a brief time and to the long-term load capacity of a controllable electronic switch of the gate unit connected to the GTO thyristor. The voltage dropping at the electronic switch is detected and compared with the predetermined characteristic curve. The electronic switch is blocked as soon as the detected switching voltage exceeds the predetermined characteristic curve. An erase pulse switches off the GTO thyristor with the controllable electronic switch.