Patent ID: 7855900

Claim:
A method of controlling phase-specific thyristors of a half-controlled network bridge, each thyristor respectively having a corresponding gate current circuit and a corresponding phase voltage being supplied to the corresponding thyristor, the method comprising: identifying a thyristor to be controlled among the thyristors on the basis of magnitudes of the phase voltages; and controlling the identified thyristor by enabling a gate current to flow to the gate current circuit of the identified thyristor through an inductive component of a constant current regulator, the constant current regulator being configured to apply the gate current to all the gate current circuits of the thyristors, the gate current being produced by a voltage source, wherein the controlling of the identified thyristor comprises: determining a magnitude of the gate current based on a potential of a conductor in the constant current regulator through which the gate current passes; and alternately switching off the voltage source producing the gate current in the gate current circuit when the magnitude of the gate current is higher than a first predetermined limit, and switching on the voltage source producing the gate current when the magnitude of the gate current is lower than a second predetermined limit.