AUTOMATIC OVERVOLTAGE PROTECTION FOR AN ALTERNATOR IN A LOCOMOTIVE PROPULSION SYSTEM

摘要

A shorted diode protection system for a traction vehicle propulsion system including a synchronous generator having armature (15) and field windings (12) and a bridge rectifier circuit (64) coupling the generator armature windings (15) to a traction motor employs a normally nonconducting solid-state controllable electric valve (71) in parallel with the generator field windings. When a rectifier diode of the bridge rectifier circuit fails short, an a-c current is reflected into the generator field winding circuit. Upon detection of this reflected current, the valve is switched into a conducting state, thereby limiting the voltage on the generator field windings.