Analyzing the dynamic performance of hybrid reluctance actuators for feedback control

This paper presents a comparative analysis of hybrid reluctance actuators (HRAs), one with a solid core and a version with a layered core, respectively. The dynamic performance is evaluated by employing flux control and current control for both actuators. With flux control, the phase lag caused by eddy current diffusion in the solid yoke HRA is reduced by 41° at the suspension mode as compared to current control. This enables the implementation of a cascaded control structure, with $\mathrm{H}_{\infty}$ position control reaching a closed-loop bandwidth of 750 Hz for the solid core HRA, similar to the conventional approach using a current-controlled laminated actuator. This offers the option to dispense yoke lamination in favor of easier manufacturing and increased yoke fill factor.