In this article, to solve the existing problems in general on-board integrated chargers, a novel three-phase on-board two-stage integrated charger is proposed by taking the unique advantages of a five-phase hybrid-excitation flux-switching (HEFS) motor. The general topologies and newly presented integrated chargers are reviewed first, and existing problems are concluded. Then, a two-stage integrated charger is proposed, and all winding selections are thoroughly investigated by theoretical analysis, finite-element analysis (FEA), and experiments. In the proposed topology, the existing problems are all solved by employing this multiphase system, reasonable winding selection, and reconfiguring the field winding. After that, a current balance control method for charge mode without a phase-locked loop circuit is presented. The simulation results verify the effectiveness of the proposed control methods. Finally, based on a 5-kW five-phase HEFS prototype machine and two sets of the three-phase generic motor controller, an experiment platform is built. The experiment results agree well with the simulation results. Therefore, the feasibility of a two-stage integrated on-board charger that can operate at any voltage level is confirmed, where only the hybrid-exciting machine and its driving system are used without any additional power devices.

In this paper, to solve the existing problems in general on-board integrated chargers (IC), a novel single-phase on-board two-stage integrated charger is proposed by taking the unique advantages of the five-phase hybrid-excitation flux-switching (HEFS) motors. The general topologies and newly presented ICs are reviewed firstly, and three main problems are concluded. Then, the proposed two-stage IC is presented, and all winding selections are thoroughly investigated by theoretical analysis, finite-element analysis (FEA) and experiments. In the proposed topology, the existing problems are all solved by employing this multi-phase system, making the reasonable winding selection, and reconfiguring the field winding. After that, a control method for charge mode and two current balance control methods are developed. The simulation results verify the effectiveness of the proposed control methods. Finally, based on a 5-kW five-phase HEFS prototype machine and two sets of the 3-phase generic motor controller, an experiment platform is built. The experiment results agree well with the simulation results. Therefore, the feasibility of a two-stage integrated on-board charger that can operate at any voltage level is confirmed, where only the hybrid-exciting machine and its own driving system are used without any additional power devices.

This paper presents a nonlinear analytical (NA) solution based on subdomains for predicting magnetic field and performances of a spoke array vernier permanent magnet (SAVPM) machine which has spoke array type permanent magnet (PM) excitation. On one hand, equivalent current sheets replace tangentially magnetized PMs to make the magnetic vector potential in the region with PMs satisfy a Laplace's equation, which simplifies the problem and reduces the workload of numerical calculation. On the other hand, in contrast to the existing literature, regions of soft-magnetic material such as a tooth and a rotor pole are subdivided into small pieces, and are no longer a whole with a single permeability for considering local magnetic saturation. Poisson's and Laplace's equations with the given permeability of soft-magnetic material are analytically solved by separation technique of variables in seven subdomains, and nonlinear iteration is used to determine the solution of NA and update soft-magnetic material permeability. NA solves the magnetic field and performances of a SAVPM machine. Frozen permeability method (FPM) is used to determine PM flux linkage and d-axis inductance under load. Results from the NA model have been compared with those from FEA and experiments.

The permanent magnet synchronous motor is the most commonly used motor in servo systems. Torque ripple caused by the variation of the airgap magnetic field limits the steady-state performance of the servo system. In this article, a novel torque ripple model is established based on the general airgap field modulation theory. A compound control algorithm based on the current feedforward algorithm is proposed to suppress the torque ripple caused by the field modulation behavior. Finite element analysis simulation is conducted to verify the effectiveness of the proposed torque ripple model. Experimental results on a prototype machine show that the proposed torque ripple model is valid and the proposed control algorithm can effectively reduce the torque ripple and improve the steady-state performance of the servo system at medium or high speed.

High-resistance connection (HRC) fault can result in the increased copper loss, thus possibly causing the damage to the electric machine drive system. Therefore, a fault-tolerant control strategy is proposed for five-phase permanent magnet synchronous machine (PMSM) drive system with HRC to minimize the copper loss. The fault-tolerant control strategy is realized based on the magnetomotive force invariance principle and copper loss minimization principle. The simulation and experiment are carried out to quantitatively validate the effectiveness of the proposed fault-tolerant control strategy. Both the simulation and experimental results show that the proposed strategy can effectively reduce the copper loss caused by HRC fault.

This article presents a sensorless motor drive scheme by a fusion of the electrical model-based estimation and the mechanical model-based observer with respect to the position servo with a heavy load. The signal injection is applied to extract the position information from the magnetic saliency. However, in the low-speed and heavy-load scenarios, the position observability degenerates in the electrical model due to the core saturation. Nevertheless, the mechanical motion states, including the rotor position, can always be adequately extracted from the mechanical motion model. The extended Kalman filter (EKF) is adopted to fuse the information from the mechanical motion perception and the signal injection-based estimation so that the speed estimate quality gets significant improvement especially when the core saturation occurs. A disturbance-rejection mechanism is introduced to resist the parameter inaccuracy and inconstancy of the EKF model. The fused estimates are applied with a model predictive control in the speed loop to realize the servo control. The sensorless scheme is validated in a heavy-load pendulum servo bench, 200% of the machine rating torque, driven by a surface-mounted permanent-magnet synchronous machine.