Through the zero-sequence current (ZSC) hysteresis controller, the existing ZSC hysteresis control-based space vector modulation (SVM) strategy can provide a satisfactory ZSC suppression effect and greatly reduce the complexity for the open-end winding permanent magnet synchronous machine (OW-PMSM) drive with common dc bus. However, the corresponding linear modulation range is reduced by 12.7% compared with the middle hexagon space vector modulation (MH-SVM) for the OW-PMSM drive. To this end, this letter improves the linear modulation range of the existing strategy. The candidate voltage vectors for each sector are re-selected, and three active voltage vectors will be employed in the extended feasible region. While ensuring the ZSC hysteresis control, the linear modulation range of the proposed strategy is the same as the MH-SVM. At last, experimental results verify the feasibility and effectiveness of the proposed strategy. The proposed strategy can suppress the ZSC effectively, and the corresponding maximum speed is the same as the counterpart of the MH-SVM.

Harmonic currents always exist in a dual three-phase permanent magnet synchronous machine due to the inverter nonlinearity, nonsinusoidal back-electromotive force, and external disturbances. This article proposes a deadbeat predictive harmonic current control (DPHCC) method to suppress the harmonic currents. The DPHCC method can directly calculate the harmonic control voltage based on the sampled harmonic currents and the machine model. Thus, the steady-state and transient-state performance of harmonic current control can be improved. Further, a disturbance observer is designed to avoid the influence of inaccurate machine parameters and other unmodeled disturbances. The observer is designed based on discrete-time sliding mode theory and an improved sliding mode reaching law. The stability of the observer has been analyzed, and the value range of the observer parameters has been determined theoretically. Finally, experimental results have been presented to verify the effectiveness of harmonic current suppression for the proposed control system.

Unprecise voltage vectors applied in conventional model predictive control (MPC) would cause additional ripples in electromagnetic torque. To eliminate the problem, this article proposes an improved model predictive torque control (MPTC) based on deadbeat solution and discrete space-vector modulation (DSVM) for dual three-phase permanent magnet synchronous machines (PMSMs). First, deadbeat-direct torque and flux control (DB-DTFC) algorithm is applied and simplified, so that the computational burden can be reduced. Second, the virtual voltage vectors (VVVs) are adopted in dual three-phase voltage vector space to reduce voltage harmonics. Also, the DSVM is further proposed in this VVVs based vector space to generate more voltage vectors. After that, the simplified DB-DTFC and the DSVM scheme are artfully combined to select suitable voltage vector candidates for the MPTC, and the best one is then chosen to control the dual three-phase PMSMs. Finally, both simulation and experimental results are given to verify the effectiveness of the proposed method.

Energy routers are indispensable in deploying energy Internet for electric vehicles (EVs), which flexibly handle the power flow regulation. Combined with the excellent characteristic of wireless power transfer technology for noncontact energy transmission, this article proposes a novel wired/wireless hybrid multiport energy router (HMER) for future EV energy Internet. First, multiple bidirectional power ports are provided to control the power flow among the grid, various dc power sources, and EVs. Moreover, with grid-tied and islanded operations, the proposed HMER enables dynamic wireless energy exchange for EVs on the move. When moving along the energy exchange lane, the EVs can receive power from the HMER and conduct energy feedback, relieving mileage anxiety while creating economic benefits. Furthermore, a mathematical model of the system is derived, and a control algorithm is introduced to perform decoupled power control for each transceiver. Finally, a SIC experimental prototype is constructed to verify the effectiveness of the proposed HMER system. Experimental results prove the transceivers can get bidirectional wireless energy interconnection on the energy exchange lane in both grid-tied mode and islanded mode, and each transceiver can realize independent power regulation.

Thermal analysis is vital in the design stage of permanent magnet synchronous motors (PMSMs). Though recent studies have developed the thermal equivalent circuit models for internal temperature calculation, they cannot consider transient modification of thermal conditions, and have a notable drawback of low accuracy. Therefore, this study addresses the neglected aspect of transient thermal analysis. A thermal network model (TNM) is proposed with inclusive coupling mechanisms, covering the increase of loss power and change of thermal parameters. Proposed TNM is combined with a dual iteration technique in order to achieve accurate prediction of thermal condition during time-stepping calculation. Also, the solving process is improved without calculating the inverse matrix after Laplace transform of the TNM system. Targeting the 10/12 PMSM that is designed and manufactured, temperature rises on motor parts are evaluated by analytical TNM, finite element analysis, and thermal tests. The study identifies the well-agreed temperature results and the necessity of transient analysis for accurate prediction of temperature rise.

In permanent-magnet synchronous motor (PMSM), the winding current consists of different orders of harmonics due to the manufacture error, deadtime, and disturbances. This article proposes a winding current harmonic suppression method for PMSM by reducing the dominant fifth- and seventh-order current ripples. First, with reference frame transformation, the fifth- and seventh-order current ripples convert to sixth-order ripples in the synchronous reference frame (SRF). Then, with further transformation, these sixth-order ripples turn to dc signals. Next, the type-II Chebyshev filter is designed to extract these dc signals. Also, the proportional-integral (PI) controller is adopted to generate the current harmonic control voltage, which is setting the dc current harmonic signals reference to be zero. Finally, the current harmonic control voltage is compensated to the voltage reference in the SRF. Both the simulation and experimental results are presented to verify the effectiveness of the proposed method.