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In this paper, a novel dual-rotor multiple-winding machine (DRMWM) is proposed for the continuous variable transmission (CVT) in hybrid electric vehicles (HEVs). First, a mathematical model of the proposed machine is constructed by using the harmonic modeling method (HMM). Then, on the basis of the magnetic field analysis, the operating principle of the DRMWM is deduced. By introducing multiple windings with two different working harmonics, namely the permanent magnet (PM) harmonics, and the magnetic gear (MG) harmonics, the proposed DRMWM can cope with various operating conditions of HEVs. To further obtain optimal performance, a finite element analysis (FEA) and multi-objective genetic algorithm II (MOGA-II) combined sequential optimization is carried out for the proposed DRMWM. The proposed optimization method is proven to be more computationally efficient compared to the global optimization method. Finally, a prototype is manufactured and tested in various operating modes. The results validate the simulation and analytical method predictions. Also, it proves that the proposed DRMWM is suitable to work as the CVT in HEVs.

The additional harmonic currents in multiphase permanent magnet synchronous motors (PMSMs) have been widely discussed and suppressed by the virtual vectors (VVs). However, the concept of VVs would result in an increasing in the switching frequency and losing the controllability in the harmonic subspace. In this article, a novel direct modulation pattern control (DMPC) method is proposed to provide the further discussion on the lower switching frequency and the better harmonic current suppression. First, a deadbeat control concept is applied to calculate the reference voltage vectors in torque production. In dual three-phase PMSM, there are several switching patterns which could generate the reference voltage vector. The designs of these switching patterns are determined according to the demand. In fact, two design concepts under the structure of DMPC is proposed. One is called the low switching frequency design. The control sets of this design is several switching patterns with only one switching signal. Another is called the low THD design. The control sets of this design is two switching patterns with opposite harmonic voltage vectors. Second, the influence of these different switching patterns in the xy currents is optimized by a cost function. Actually, there are two types of cost function. One is a multiobjective cost function, which is designed to regulate both the amplitude of switching patterns and suppress the xy currents. Another is derived from the first cost function that regulates only the xy currents. The amplitude is determined directly in the voltage vector calculation. Finally, the experimental results show a good performance of these control strategies, in terms of the αβ currents production, the xy currents and the switching frequency reduction.

This article presents a high-fidelity analytical solution and a fast integrated optimization method for vernier machines. First, a harmonic modeling method (HMM) is adopted to obtain the magnetic field distribution of vernier machines. Particularly, the stator teeth of vernier machines are divided into several blocks to take account of the local magnetic saturation of soft-magnetic material. Then, the electromagnetic parameters, such as the average torque, torque ripple, and efficiency, can be calculated via the analytical model. Next, the proposed harmonic model is combined with the nondominated sorting genetic algorithm II (NSGA-II) to determine a multiobjective optimal design for the studied vernier machine. This integrated optimization method can save computation time, because the data interaction process between the finite-element analysis (FEA) software and the optimization software is eliminated. Finally, the performances of the optimal case are verified by both FEA and experiments with the prototype.

Based on the electromagnetic-structural coupling analysis, this article proposes the comparative study of three double-stator interior- permanent magnet vernier (DS-IPMV) machines, including the spoke-PM, V-shape-PM (V-PM), and H-shape-PM (H-PM) rotor structures. DS cooperation strategies are adopted in the machine design for the performance improvement. Firstly, the rotor optimization of the proposed machines is carried out, with consideration of the tooth-slot cooperation between the rotor and stators. The electromagnetic- structural coupling-simulation is adopted for comprehensive evaluation. Then, the specific performance comparison is carried out, including the magnetic, structural and cost analysis. Consequently, the spoke-PMV machine accommodates the highest torque output, efficiency and cost-effectiveness; meanwhile, the V-PMV machine possesses the highest torque per PM volume with the better ripple performance. Accordingly, prototype experiments are carried out for the validation of the proposed machine design and comparison.

This article presents a new direct load voltage control method for electrolytic capacitorless wireless power transfer (WPT) system without dc/dc converter. In specific, the three-phase low-frequency ac to the high-frequency ac (HFac) converter is employed into the electrolytic capacitorless WPT system by using the bidirectional power switches. The HFac voltage is directly generated on the transmitting tank without using the electrolytic capacitor. Furthermore, in order to realize the discretionary and accurate load voltage control without dc/dc converter, the nine voltage vectors, including six effective voltage vectors and three zero voltage vectors, are selectively exported for the transmitting tank with different duty cycles. In addition, the unity power factor correction and direct load voltage control are both achieved only by transmitting side control. Meanwhile, theoretical analysis of double series-compensated transmitting network and duty cycles under resonant frequency calculation in microchip are demonstrated in detail. Finally, both simulation and experimental results are provided to verify the feasibility and correctness of the proposed system, which operates at 85 kHz with 90% efficiency and about 9% total harmonic distortion.

Parameter mismatches in a control scheme would cause the additional harmonic components and torque ripples in permanent magnet synchronous machines (PMSMs). Moreover, there is an additional leakage inductance mismatch in dual three-phase PMSM when comparing with its three-phase counterparts. In this article, a robust model predictive current control (MPCC) scheme is proposed in order to release the parameter dependence of model predictive control (MPC) in application of dual three-phase PMSM. First, 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 the proposed robust MPCC scheme could estimate the inductance information and eliminate the influence of parameter mismatches.

This article presents a wireless power transfer (WPT) system that can deliver power to multiple receivers concurrently with additional resonant frequencies and reduced power switches. It employs three-phase high-frequency inverter with delta-type transmitting tanks. In this way, this WPT system can transfer the power with different resonant frequencies to multiple receivers simultaneously. Compared with the typical multiple-frequency and multiple-receiver WPT system, the proposed WPT system can save considerable amount of power switches. In addition, three additional resonant frequencies can be obtained by setting up original equivalent resonant tank in transmitting side without any change. Three modes, namely the single frequency transmission, concurrent frequency transmission, and additional frequency transmission, are performed and analyzed in detail. Finally, a test rig is built up to verify the performances of six independent frequencies, six kinds of concurrent double frequencies, and one concurrent ternary frequency transmission, with one dealt type transmitting tank.

This paper presents a model predictive control for a six-phase permanent magnet synchronous machine (PMSM) with a reduced-dimension cost function. Only the variables in the harmonic subspace are included into the cost function, while the energy conversion related variables are excluded. This is achieved by using the deadbeat direct torque and flux control method to obtain a reference voltage vector and then to track the torque and stator flux properly in the energy conversion related subspace. Then, according to the position of the reference vector, the appropriate prediction vectors can be determined. Subsequently, a reduced-dimension cost function including only the harmonic constraints is defined to evaluate the feasible prediction vectors. In this way, the predictive model and the cost function are simplified without redundant constraints. Meanwhile, the torque and flux can be regulated satisfactorily, and the harmonic currents are suppressed effectively. Finally, experimental results of the proposed method and the conventional model predictive torque control are presented in this paper to verify the validity of the proposed method.

This paper presents a safe charging operation for the integrated on-board electric vehicle (EV) charging system, where the power electronic components are reconfigured from the propulsive system. First, the rotational movement is detected and analyzed, when the motor windings are reutilized as the dc–dc inductors. Then the safe charging operation is investigated, which is based on the analysis of the charging torque and the ripple currents. Moreover, a new control strategy is presented with the purpose of the safe operation and smoothing reactor during the EV charging process. Finally, both simulation and experimentation are carried out to verify the safe charging operation. The results prove the feasibility and validity of the proposed safe charging operation for on-board charger with the three-phase interior permanent-magnet motor.

This paper presents a new effective sandwiched wireless power transfer (WPT) system, which is adopted to recharge the battery of a micro medical robotics for a cardiac pacemaker. The key of the design is to use the distinct sandwiched topology in both the transmitter and receiver coils, whose operating frequency of 160 kHz is significantly lower than the reported WPT system up to megahertz. Furthermore, the implantable receiver adopts the bilateral coil design, which can harness more power within a limited size. Meanwhile, with the sandwiched transmitting coils, the proposed design achieves the high feasibility and flexibility of the controllable distance for different kinds of micro medical robotics in patients. As a result, the proposed system can provide the power as high as 5 W and the transmission efficiency up to 88%. Finally, the corresponding theoretical analysis, simulation, and experimentation are carried out to prove the validity of the proposed sandwiched medical WPT system for the implantable device in the patient body.

In this paper, a wireless ballastless lighting system for fluorescent lamps is proposed and implement-ted. The key is to utilize magnetic resonant coupling to achieve wireless power transfer (WPT) while igniting the fluorescent lamp without using any magnetic or electronic ballast. Meanwhile, series-parallel compensation is identified to be more suitable for this WPT system. Also, burst firing control is utilized to achieve efficient light dimming. In order to achieve the fully wireless feature, remote lighting control via Bluetooth is realized by a smart phone. As an example, an experimental setup, which can light up an 8 W fluorescent lamp with illuminance of 2330 lx, has been designed and developed. In particular, it can achieve the transmission efficiency of 57% and the operating frequency of 51 kHz, with distance up to 56 cm. Both theoretical analyses and experimental results are given to validate the feasibility and flexibility of the proposed system.

In this paper, a new class of wireless secondary converterless switched reluctance motor (WSC-SRM) drives is proposed and implemented. The key is to develop a unique wireless power transfer (WPT) system to directly drive the SRM without involving any power converter at the motor side. This is particularly essential to enable the WSC-SRM to work in an isolated environment without maintenance. Based on the selective WPT, the phase windings of the SRM can be properly energized by the same transmitter that adopts a newly developed compound structure. Meanwhile, signal duty ratio control of the transmitter is employed to achieve the speed control of the WSC-SRM. Both simulation and experimental results are given to validate the feasibility of the proposed system. For exemplification, a prototype is designed and constructed, which can provide WPT up to 150-mm transmission distance and achieve up to 72.8% transmission efficiency.

In this paper, a phase-decoupled flux-reversal linear generator for low-speed reciprocating power generation is presented. The proposed linear generator adopts a short-primary and long-secondary structure. The primary consists of six identical C-cored modules housing both permanent magnets (PMs) and the armature winding. The secondary is passive and stationary. By using the independent C-cored modules and flux-reversal configuration, six phases are magnetically decoupled from each other. In order to maximize the delivered power from the linear generator to the load, an impedance matching strategy is applied to suppress the circuit reactance. Both simulation and experimentation are carried out to verify the effectiveness of the proposed linear generator and the impedance matching strategy.

This paper proposes a new electronic-geared (EG) magnetless machine for electric vehicles. The proposed EG machine can offer the multitooth bipolar-flux (MTBF) operation for the low-gear (high-torque low-speed) situation, and the single-tooth unipolar-flux (STUF) operation for the high-gear (low-torque high-speed) situation. In particular, the balance-position winding arrangement is proposed to enable the machine having balanced flux linkages. Consequently, the proposed machine operates as the brushless ac machine for MTBF operation, leading to offer smoother torque at the low-gear situation. Meanwhile, it operates as the brushless dc machine for STUF operation, leading to produce better torque density at the high-gear situation. Various performances of the proposed EG machine are analyzed, with emphasis on the validity of electronic gearing. The experimental prototype is also built for verification.

A new permanent-magnet (PM) hybrid brushless (PMHB) machine is proposed and implemented as the integrated starter-generator (ISG) for hybrid electric vehicles (HEVs). It has the advantages of higher torque density than other PMHB machines and much wider speed range than other PM brushless machines. The key is to tune its dc-field winding current in such a way that three major modes of ISG system operation for HEVs, namely, engine cranking, battery charging, and torque boosting, can be achieved effectively. The finite-element method is employed to simulate its steady-state and dynamic performances. Finally, a 2-kW prototype is constructed and tested to experimentally verify the simulation results and the validity of the proposed ISG system.

With ever-increasing concerns on our environment, there is a fast growing interest in electric vehicles (EVs) and hybrid EVs (HEVs) from automakers, governments, and customers. As electric drives are the core of both EVs and HEVs, it is a pressing need for researchers to develop advanced electric-drive systems. In this paper, an overview of permanent-magnet (PM) brushless (BL) drives for EVs and HEVs is presented, with emphasis on machine topologies, drive operations, and control strategies. Then, three major research directions of the PM BL drive systems are elaborated, namely, the magnetic-geared outer-rotor PM BL drive system, the PM BL integrated starter-generator system, and the PM BL electric variable-transmission system.