Parameter mismatches in control scheme would cause the additional harmonic components and torque ripples in PMSM. Moreover, there is additional leakage inductance mismatch in dual three-phase PMSM when comparing with its three-phase counterparts. Then, in order to release the parameter dependence of model predictive control (MPC) in application of dual three-phase PMSM, this paper proposes a robust model predictive current control (MPCC) scheme. Firstly, the parameter sensitivity of conventional MPC in dual three-phase PMSM is discussed. Then, an incremental predictive model is applied to reject the influence of flux mismatch. Additionally, the concept of virtual vectors is introduced to deal with the influence of leakage inductance. In this case, the predictive errors are the result of inductance mismatches. Therefore, the inductance information could be obtained through the predictive errors. Finally, a discrete inductance compensation system is applied to update inductance. Comparative simulation and experimental results both verify that proposed robust MPCC scheme could estimate the inductance information and eliminate the influence of parameter mismatches.

The performance of model predictive control mainly depends on the accuracy of model and parameters, such as the back electromotive force (EMF) harmonics in dual three-phase permanent magnet synchronous motors (PMSMs). However, the back EMF harmonics would vary with the operation conditions. Thus, the parameter mismatches in the harmonic subspace would be inevitable. In this article, a direct harmonic current control scheme is proposed to provide further harmonic current suppression under parameter mismatches in the xy subspace. First, deadbeat control concept is applied to calculate the reference voltage in the αβ subspace. This reference voltage vector is utilized to generate a group of control sets with different voltage vectors in the xy subspace. Then, a slide mode control scheme is provided to deal with the inaccurate parameters in the xy subspace. The reference voltage vector in the xy subspace is obtained with this slide mode control scheme without the remaining inductance parameters. Third, a two-step modulation method and cost function are discussed to further suppress the harmonic currents. The control sets generated by deadbeat control are optimized with the cost function. Moreover, a switching pattern with fixed switching frequency is proposed in this section. Finally, experimental results verify that proposed control scheme could further suppress the harmonic currents.

This article proposes a novel flux weakening scheme for five-phase PMSM with active harmonic currents injection. The conventional flux weakening control schemes applied in the five-phase PMSM do not consider the voltage limit drop in the fundamental subspace due to the harmonic current controller. Thus, the derivation between the reference current trajectory and actual current trajectory would cause the current distortion when applying deadbeat current controller (DBCC). This article analyses the precise voltage limit circles considering the voltage drop caused by the resistance and harmonic currents control at first. Then, a feed-forward flux weakening control algorithm is designed to optimize the current trajectory online. The gradient descent method is used to ensure the converge speed and stability of the optimized current trajectory. Thirdly, the peak value of phase currents would be clipped by the harmonic currents to prevent the inverter current limit, where a new non-linear harmonic current controller is designed to precisely control the harmonic currents. Finally, the DBCC and modified SVPWM technology are utilized to generate the duty cycle. The proposed improved flux weakening control strategy is successfully implemented in an interior five-phase PMSM, and the performance demonstrate the effectiveness of this strategy.

The performance of flux-weakening controllers in the multiphase permanent magnets (PM) machines depends on the accurate fundamental voltage limit derivation, and the minimal copper loss design in the flux-weakening operation region has not been well discussed. In this article, the accurate fundamental voltage limit with considering harmonic current suppression is derived at first. Then, two control concepts are addressed, and the corresponding flux-weakening control strategies are designed with the gradient descent method. In the first control strategy, both the fundamental and harmonic voltage vectors are feasible, resulting in the larger amplitude of the phase currents. The second control strategy obtains higher bus voltage utilization by an additional transition stage. At the same time, the harmonic currents cannot be further suppressed in the flux-weakening operation region. Third, the copper loss per electrical cycle is calculated, and a switching scheme is designed to obtain lower copper loss in the flux-weakening operation region. Finally, both strategies are successfully implemented in a dual three-phase PMSM. Moreover, the proposed switching scheme obtains minimal copper loss in the whole flux-weakening operation region.

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.

Most of the existing one-to-multiple wireless power transfer (OWPT) systems are single-channel one-to-multiple wireless power transfer (SOWPT) systems. They only utilize one power channel to charge multiple receivers. In this paper, a novel multi-channel one-to-multiple wireless power transfer (MOWPT) system is proposed, which can deliver power to different receivers simultaneously with separately power channels. In the proposed MOWPT system, the composited compensation topology is utilized to build multiple power channels, which possess totally variou resonant frequencies and nearly do not affect each other. Compared to those existing SOWPT systems, the power of receivers of the proposed MOWPT system can be simply and separately controlled by changing the duty cycles of the inverters without a complex control method and extra DC-DC converters. In order to analyze the performances of the proposed MOWPT system, a 0-LC MOWPT system, which utilizes the air-transformers to provide multiple power supplies of different frequencies, is modeled and analyzed in detail. Moreover, based on the analysis results, a corresponding parameter design method is proposed to simplify the design procedure of this MOWPT system. Finally, an experimental prototype is built up to verify the performances of the proposed MOWPT system and the parameter design method.