Dynamic brake circuit and semiconductor inverter using dynamic brake circuit

摘要

The voltage change (dv / dt) occurring in the inverter can directly switch the semiconductor braking switch to prevent the inverter from shorting during operation.;When braking the motor 10 driven by an inverter unit consisting of a three-phase AC power supply 1, a three-phase bridge rectifier 3, a smoothing capacitor 6, and a semiconductor switching element 7, a semiconductor switching element ( In the dynamic brake circuit which triggers 14 and shorts the feed line 11 of the motor 10 and absorbs energy by the braking resistor 15, the anode side of the smoothing capacitor 6 and the semiconductor braking switch 14 The high resistor 20 is disposed between the anode sides and the snubber capacitor 17 of the snubber circuit 18 connected in parallel with the semiconductor braking switch 14 is charged through the high resistor 20 before the inverter operation. I made it possible.