Control method for reducing the power loss of the main thyristor of a D.C. chopper converter during the braking mode of a vehicle motor

摘要

The intention is to disclose a control method for reducing the power loss of the main thyristor of the D.C. chopper converter, which thyristor is constructed as a turn-off thyristor, during the hazard braking mode of a vehicle motor when the D.C. chopper converter circuit is operating with disconnected brake rheostatic controller and a contact line network is disconnected, during hazard braking mode, from the mains capacitor which is connected upstream of the D.C. chopper converter. The control method is characterised in that the drive level of the brake thyristor is adjusted by means of a control variable (wU) for the voltage (UC) at the mains capacitor, which voltage (UC) is predetermined in terms of its characteristic curve as a function of the rpm (n) of the vehicle motor. Furthermore, the frequency of the ignition signals (ZHT and ZBT) is predetermined in terms of the characteristic curve for the main thyristor of the D.C. chopper converter and for the brake thyristor as a function of the rpm (n) of the vehicle motor. <IMAGE>