Collector ring also failed, to introduce you to.
Large generators and self-excitation system running collector ring device failure rate is relatively high, the light less load operation, severe damage to the equipment. The reason is to brush and collector ring of mechanical friction and the large current must generate heat, while the collector ring means shafting way the limit of the rotary union
conditions and cooling, and cooling conditions are relatively poor. The heat on the collector ring means relative concentration, higher temperatures. Such as in the design, manufacture and operation of the slightest mistake will lead to accidents.
During normal operation, the three-phase winding leads to the collector ring by resistor short-circuited. A symmetrical three-phase windings are wound around. Startup, the rotor winding string into a start-up resistor to rotary joints
reduce the starting current of the purpose. Since the startup resistor may be piecewise resection string into appropriate starting resistor, it is possible to achieve the maximum torque of the electric motor, the starting torque to shorten the startup process.