CIRCUIT FOR SUPPRESSING SERIAL THYRISTOR REVERSE RECOVERY TRANSIENT VOLTAGE

摘要

PURPOSE:To suppress di/dt of a turning ON current of a thyristor with a simple and inexpensive structure by making the turning ON current of the thyristor to flow to a saturable reactor. CONSTITUTION:A parallel connecting circuit of a low resistor 1 for suppressing the reverse recovery transient voltage of a thyristor and a saturable reactor 2 is connected in series with a serially connected thyristor circuit 3. A diode 4 is connected in series in reverse direction to the thyristor of the circuit 3 with the resistor 1. A diode 4 is turned ON when the circuit 3 is reversely recovered, the current flows to the resistor 1 and the reactor 2, and since the diode 4 is turned OFF when the circuit 3 is turned ON, the turning ON current flows to the reactor 2.