A system for turning on thyristors is presented, the system comprising: an input configured to be coupled to a power source; an output configured to be coupled to a load; a first branch coupled between the input and the output and including a first thyristor having a first threshold voltage; a second branch coupled between the input and the output and coupled in parallel with the first branch, the second branch including a second thyristor having a second threshold voltage higher than the first threshold voltage; and at least one controller configured to control the system to selectively generate a biasing voltage across the second thyristor to induce a change in a voltage across the second thyristor from a first voltage to a second voltage, the first voltage being less than the second threshold voltage and the second voltage being greater than the second threshold voltage.

Provided is an electric circuit that may be part of a power converter and which includes a plurality of electrically connected thyristors. Each thyristor has a gate terminal electrically connected to a gate drive unit adapted to generate gate pulses for triggering the thyristor. At least one of the plurality of gate drive units is adapted to measure the gate voltage of the respective thyristor after one or more gate pulses have been applied to the respective thyristor. The measured gate voltage may be used to determine if a thyristor has not been triggered by the gate pulse(s) e.g., if the gate voltage is below a voltage threshold.