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Radial force and torque are the control objectives that determine the machine performance of levitation and rotation in a bearingless switched reluctance motor (BSRM). This paper proposes a control scheme for rotating and levitating a 12/8 BSRM. The motor average torque and radial force are independently controlled with hybrid excitations in main windings and levitation windings. First, the mathematical relationship between radial force and currents, which is utilized in this paper, is derived by using the Maxwell stress tensor method. Then, the proposed control scheme is analyzed. The average torque of each phase generated in the levitation region equals zero for its symmetry of the aligned position. Accordingly, the current calculating algorithm is deduced to minimize the magnitude of instantaneous torque in the levitation region. The principle and realization of the proposed scheme are demonstrated with finite-element (FE) analysis. Experimental results show that the proposed scheme is effective for a stable levitation.

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Examining the resting-state networks (RSNs) may help us to understand the neural mechanism of the frontal lobe epilepsy (FLE). Resting-state functional MRI (fMRI) data were acquired from 46 patients with FLE (study group) and 46 age- and gender-matched healthy subjects (control group). The independent component analysis (ICA) method was used to identify RSNs from each group. Compared with the healthy subjects, decreased functional connectivity was observed in all the networks; however, in some areas of RSNs, functional connectivity was increased in patients with FLE. The duration of epilepsy and the seizure frequency were used to analyze correlation with the regions of interest (ROIs) in the nine RSNs to determine their influence on FLE. The functional network connectivity (FNC) was used to study the impact on the disturbance and reorganization of FLE. The results of this study may offer new insight into the neuropathophysiological mechanisms of FLE.

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The problem of voltage/current ripples has become a primary power quality issue for dc systems, which could seriously degrade the performance on both the source side and the load side and lead to reliability concerns. In this paper, a single-phase Pulse width modulation-controlled rectifier is taken as an example to investigate how active control strategies can improve the power quality of dc systems, reduce voltage ripples, and, at the same time, reduce the usage of electrolytic capacitors. The concept of ripple eliminators recently proposed in the literature is further developed, and the ratio of capacitance reduction is quantified. With such ripple eliminators, this power quality problem is formulated as a control problem to actively divert the ripple current on the dc bus. The main focus of this paper is to investigate how advanced control strategies could improve the performance of ripple eliminators. An advanced controller on the basis of the repetitive control is proposed for one possible implementation of ripple eliminators in the continuous current mode (CCM). Experimental results are presented to verify the effectiveness of the strategy with comparison to another ripple eliminator operated in the discontinuous current mode. It has been shown that the proposed instantaneous ripple-current diversion in CCM leads to a nearly fourfold improvement of performance.INDEX TERMS Instantaneous diversion of ripple currents, CCM, DCM, ripple eliminators, voltage ripples, repetitive control, reliability, electrolytic capacitors.

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