Speed range enhancement for five phase induction motor drive using reconfiguration of five phase supply

Abstract

In modern electrical circumstances of society lead the development of technology in every field of science, due to ever increasing demand of more power it is necessary to supply it at a certain voltage level economically, which restrict it to a particular value. Moreover there are other boundaries on utilization side as well, for energy consumers and producers. The solution for this is use of multiphase systems. These days multiphase systems are being contemplated as a elucidation for the predicament and research in this field is picking up rapidity. There is a need to acquire multiphase supply from the existing three phase supply due to its inherent advantages. One of the advantages of multiphase machine is that it can be used in high speed applications. Enhancement of speed range in the multi phase machine achieved by either the corresponding inverter operated with high voltage or sinking the value of counteract emf of machine using the techniques of field weakening. An n-phase machine (where n>3) can be allied in (n+1)/2 different ways i.e., called reconfiguration. With these available alternatives, the speed range of an n-phase can be significantly increased. In such connection different torque-speed characteristics are realized. For an odd number of phases, the stator winding of a multiphase machine connected in (n+1) different ways. The first two are normal star connection and delta connection. The remaining are the swap delta connections which are obtained by changing the phase sequences.