Patent ID: 8736205
Filing Date: 2014-05-27
Classification: H02P

Abstract:
1. A method for terminating a braking process of a three-phase AC motor, wherein the braking process of the AC motor is performed by way of a switching device, wherein the switching device includes a first, second and third AC motor line, a first and third supply line and a first and second thyristor, wherein the first, second and third AC motor lines are connected to the AC motor, wherein the first thyristor is connected to the first supply line and to the first AC motor line, the second thyristor is connected to the first AC motor line and to the second AC motor line, and the second AC motor line is connected to the third supply line, wherein the actuation of the first and second thyristors is performed by a processing unit of the switching device, wherein during the braking process of the AC motor, the method comprising: actuating, via the processing unit, the first thyristor in such a manner that a braking current is injected into the AC motor by way of the first and third supply lines such that a torque which brakes the AC motor is produced; actuating, via the processing unit, the second thyristor in such a manner that when the first thyristor is quenched, the braking current is taken on by the second thyristor and the braking torque is maintained; repeating, via the processing unit, the actuating of the first and second thyristor; and suppressing, at the end of the braking process of the AC motor and via the processing unit, an actuation of the second thyristor after a last actuation of the first thyristor so that the second thyristor does not take on the braking current.