This paper proposes a novel consequent-pole hybrid excited vernier machine (CPHEVM) by combining hybrid excited concept and vernier structure, and the consequent-pole magnet arrangement is employed on outer rotor. The proposed machine can achieve high torque density at low speed and excellent flux-weakening capability at high speed, which are highly desirable for electric vehicle applications. The DC field windings are embedded between modulating poles, which increase the space utilization ratio to enable flux regulation without decreasing torque capability. The configuration, operation principle and design consideration of the proposed CPHEVM are described, respectively. Finite element method is employed to analyze the electromagnetic performance of the selected CPHEVMs with various slot/pole combinations, including flux regulation capability, back-electromagnetic force, and torque characteristics with and without flux-weakening control.

The axial permanent magnet magnetic bearingless flywheel machine (APM-BFM) mostly operates under the state of high-power fast charging and discharging. Due to the characteristics of high-power density per unit volume, the centralized windings have small heat dissipation area and high thermal loads, the temperature rise on APM-BFM is a very important issue. Thermal analysis is thus of particular importance particularly for modern machines since the temperature rise and distribution are significant during their running under higher electromagnetic loads commonly used nowadays. In this paper, the equivalent thermal network method is proposed to evaluate the temperature rise of the APM-BFM. The equivalent thermal network model is established based on the basic theorem of heat transfer. The thermal resistance and heat source in the machine are analyzed and calculated, and the thermal balance equation is established. The temperature rise of each node is solved, and finally the validity of the model is verified by finite element magnetic-thermal coupling simulation.

This paper proposes a novel power-fed permanent magnet adjustable speed drive (PF-PMASD) to regulate the speeds of pumps and fans for energy saving. The drive features that the slip power induced in the wound rotor of the drive can be fed to the power grid by a power electronic converter. The structure, operation principle, and control strategy of the drive are introduced and investigated. The mathematical model of the PF-PMASD is built by referring to the models of the traditional permanent magnet synchronous machine and wound rotor induction motor, based on which the power-size equation for the drive is deduced. The losses and efficiencies of the drive under different slips are also calculated and evaluated. The relationships between the slip and the duty cycle of the insulated-gate bipolar transistor in the boost chopper are revealed by the mathematical model of the control unit. The steady characteristics including electromotive forces, phase currents, and torques under different operation states are computed and analyzed comprehensively by finite-element analysis. The speed regulation characteristics, the power factor, and the energy-saving capabilities of the drive are investigated by experimental test. The analysis results indicate that the proposed PF-PMASD possesses a remarkable speed regulation capability with high efficiency.

This paper proposes a novel flux adjustable permanent magnet eddy-current coupling with a movable stator ring (MSR). The slip speed of the proposed coupling can be adjusted by shifting the MSR along the axial direction. The structural feature and operation principle of the coupling are illustrated. An analytical model based on magnetic equivalent circuit method is built to compute its electromagnetic characteristics efficiently. The dynamic process of the MSR movement is simulated by employing a variable air-gap reluctance model. The eddy-current field under asymmetric magnetic field is calculated by an improved analytical method. The electromagnetic characteristics of the coupling, such as air-gap magnetic field, eddy-current, and torque-slip speed characteristics, are analytically investigated. The analytical results are verified with the results obtained by the 3-D finite-element method.

This paper presents the simple analytical modeling for switched flux memory machine to provide in-depth insight into its working mechanism. The analytical approach is based on the slotless open-circuit air-gap flux density and the slotted air-gap relative permeance calculations for a doubly salient structure. In addition, due to low coercivity and highly nonlinear hysteresis curve at the second quadrant, the piecewise and virtual-linear hysteresis models of AlNiCo permanent magnet (PM) are presented to determine the PM working point. This combined analytical solution allows rapid calculation of several electromagnetic characteristics, e.g., air-gap flux density and back electromotive force. The effectiveness of the analytical method is validated by both finite-element results and measurements.