DESIGN OF ASYNCHRONOUS MACHINES

Last years asynchronous machines, operating in motor and generator modes, find application in the independent systems of electrical equipment. Asynchronous generator of three-phase current with the rotor winding, executed as a squirrel cage, has a series of advantages : it is simple by a design, does not have sliding contacts, possesses high reliability. High mechanical durability of rotor allows to use a generator for large angular speed of rotation. The power consumption on voltage control at the use of bias method of armature back is small (in 5÷10 times less, than at magnetoelectric generators).

An asynchronous machine, being combined motor-generating unit in the independent systems of electrical equipment, can operate in two modes − motor and generator. In the motor mode there is an acceleration of machine with a turbine to nominal speed, i. е. it operates in the starter mode. At working substance supply to a turbine and disconnecting of external feed an asynchronous machine passes into the generator mode, here the process of passing into the independent system does not require an interruption in the users feed. Starting time of plant is reduced.

The lack of asynchronous generators, limiting their application, are a necessity of application of excitation capacitors and complication of voltage control.