SIX-PHASE WINDINGS OF ASYNCHRONOUS ENGINES
Abstract
One of ways of improvement of operational characteristics of adjustable-speed induction motors is the increase in number of phases of a stator winding from three to six. A current consumed by one phase of a stator winding six-phase induction motor, approximately twice less than a consumed phase current of its three-phase analogue. Thanks to it, in drives of average and big capacity there is a possibility to reduce current load on an inverter phase at simultaneous increase in their quantity. Was considered that six-phase winding can be received from three-phase by replacement of six-phase zones A, C', B, A', C, B' on six phases A, B, C, D, E, F with 60º phase zone. In this case six-phase winding turns out two-layer. Here the analysis of possible schemes six-phase windings in 36 and 24 slots of stator with number of poles 2р=4 and 2р=2 is resulted. Schemes of six-phase windings of different designs for adjustable-speed induction motors are offered. Was considered that six-phase windings can be only two-layer. However, performance of single-layered windings is possible. Application of single-layered windings simplifies manufacturing techniques of six-phase engines. Schemes of single-layered six-phase windings among grooves статора Z1=36 with number of poles 2p=4 are resulted at change of alternation of phases, and also among grooves Z1=24 with number of poles 2p=2 at change of a numerical number and alternation of phases of a winding. Application six-phase induction motors will lead to considerable decrease in vibration and magnetic noise in comparison with similar indicators in three-phase the induction motors that promotes decrease in pulsations of the torque and speed on a shaft of the motor and increase of its reliability. Having considered the presented schemes of six-phase windings, it is possible to draw a conclusion that in spite of the fact that six-phase windings cannot be designed with 30º phase zone, all the same there is a possibility of their designing in single-layered execution.