Research on a Low Power Consumption Six-Pole Heteropolar Hybrid Magnetic Bearing

This paper reports the work on a six-pole heteropolar radial hybrid magnetic bearing (HMB). Its configuration and working principle are introduced. The mathematical model is built based on equivalent magnetic circuit and coordinate transformation method. The model shows that the coupling in x and y directions is very low and can be ignored when the rotor is around the central position. A decoupling controller for this six-pole HMB is obtained. A design principle for bias flux density is presented based on maximization of load capacity in different directions, through which a prototype six-pole HMB for a five-degrees-of-freedom magnetic bearing system is designed and assembled. Both the simulation and experimental results show that the rotor can be suspended steadily and the whole control system has good dynamic and static performance. Finally, tests were done to determine power losses. As a result, the total power consumption of this six-pole HMB is just 12.77 W for a 2.2 kg rotor, which is only 13.35% of a traditional eight-pole active magnetic bearing with the same load capacity.