Speed Regulation Technique of One Bearingless 8/6 Switched Reluctance Motor With Simpler Single Winding Structure

Abstract

Some types of bearingless switched reluctance motors (BSRMs) have been developed up to now. Their differences mainly focus on different stator-rotor tooth number and winding structures: two layers of windings and single layer of windings for 12/8 or 8/6 BSRM. Their driving principles are just the same: driving current and radial force current are regulated to generate torque and radial force separately. The main difference is the loading of two currents on one single layer of windings or on two separate layers of windings. Further analysis proves that single layer winding structure has more advantages, for example simpler motor and winding structure. Based on the above researches, one 8/6 BSRM with simpler single layer of winding structure has been developed furthermore. Its main characteristic is that the total winding number of motor is decreased from eight to six, which is only two more than four windings of a normal 8/6 SRM. Only six converters are demanded to achieve levitation operation. Its special driving theory and speed regulation technique of the motor by applying three phase windings have been introduced. To testify the new idea, theoretical analysis and practical test have been finished for one test motor. One initial speed of 5000 r/min of levitation operation has been achieved.