Comparison between pole-placement control and sliding mode control for 3-pole radial magnetic bearings

Sensorless control of three-pole active magnetic bearings using saliency-tracking based methods

“…By algebraic manipulation of (13) to (17) the flux densities required to produce these force components can be obtained (18), (19) and (14).…”

“…This assumption can introduce some errors in the resulting force that can be easily compensated by the position regulator. A more detailed model including displacement information has been developed in [18].…”

“…References to current regulator are obtained from the real and imaginary components of equation (21). In this paper, the position controller is implemented using the sliding mode control method described in [18]. Since the inductante matrix shown in (12) is a function of the x and y axis displacement of the rotor shaft, it can be used for position estimation purposes.…”

A Generalized Unbiased Control Strategy for Radial Magnetic Bearings

“…The approach converts the current-to-force relationship for a three-pole bearing to a simple complex-valued expression that is straightforward to invert. Other works experimentally demonstrated the viability of the control approach [2,3].…”

“…The present work extends the method of unbiased control considered in [1][2][3] (which only applies to three-pole magnetic bearings) to encompass radial magnetic bearings with an arbitrary number of poles, such as the nine-pole bearing pictured in Figure 2. Other ramifications of this generalized unbiased approach are addressed in this work, including control of bearings with more than three poles using 3-phase drives and fault tolerant unbiased bearings.…”