Turning induction motors in four poles active magnetic bearings with coupled fluxes

Nowadays, active magnetic bearings (AMBs) can be found operating in several applications. The fabrication of these devices can be considered a mature issue as a consequence of several decades of research and developing. Nevertheless, the related cost of the construction of its parts continues to be high. This is particularly true as the commissioning requires previous information like the machine shaft dimensions where these devices are going to be working. Even more, when there is not an automatic tool to mount their windings, this work continues to be manually. With this in mind, the possibility to use conventional induction motors to reduce the cost of active magnetic bearings is presented in this work. Different to the conventional (AMBs), the magnetic fluxes distribution is based in the coupled one structure as found in a four poles conventional AC motor with distributed windings. Through Finite Elements analysis, a two phase and a three phase cases are considered. Experimental results, using the two phase version, validate this approach.