Braking system for electrical traction - has resistance winding between motor armature and rectifier and thyristor acting as inverters at high speed and rectifiers at low speed

摘要

The braking system has two traction motors whose field windings can be switched to a direct current potentional by a pole reversing switch. The traction motor armatures are connected in series to a rectifier equipped with thyristors. A brake resistance is included in one of the connections from armature to rectifier and bridged by switch during traction conditions. For braking conditions, the resistance is opened causing the poles to reverse. The braking force can be varied by a current regulator. The armature current is determined and a proportional voltage is fed to a comparator. The difference is fed to an amplifier to regulate the thyristors. The thyristors respond by acting as inverters at high speed and rectifiers at low speed.