Speed-setting system for several electric motors - has several three=phase, simultaneously-fed AC networks of different frequency for feeding async. squirrel-cage motors

摘要

The speed adjusting system is for several electric motors, supplied from the mains, in an installation in which the motors drive operating machines in a prodn. line, etc. The electric motors are of asynchronous, squirrel-cage type with a variable number of pole pairs, supplied by several, simultaneously-fed three-phase networks of different frequency. A speed selector device is independent of switching of other asynchronous motors to the respective networks and connects each asynchronous motor, in dependence on the required speed to the feed networks. It connects each motor separately or together with other motors to networks with frequencies, corresp. to the required speed. It can also select the respective number of pole pairs. The networks are provided by one or several dynamic converters, supplied from a common circuit.