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This paper proposes a new Vernier reluctance machine (VRM) drive for electric vehicle. The key is to incorporate both stator-slot permanent magnets (PMs) and zero-sequence current as the excitation source to establish a parallel magnetic field and interact with armature winding. In this way, two different machines, namely, slot-PM-excited VRM and dc-excited doubly salient machine, are artificially integrated into a single structure, which contributes to enhance the torque density. Moreover, flexible flux control can be realized by regulating zero-sequence current. In this paper, the machine structure and operation principle are introduced, with its feasibility verified by both finite-element analysis and prototype experiments. [ABSTRACT FROM AUTHOR]

In this paper, we propose a loss calculation method considering minor hysteresis loops for permanent magnet (PM) motors driven by pulsewidth modulated (PWM) inverters. In the governing equation of the proposed method, both the effects of the major and minor hysteresis phenomena are expressed by a reaction magnetic field. This field is determined by iterative calculations of finite-element analysis (FEA) with a simple hysteresis modeling that considers the minor loops. The proposed method is applied to a PM motor, and the experimental verification is carried out. It is clarified that the minor hysteresis loops affect not only the hysteresis loss but also the eddy current loss because the skin depth varies with the differential permeability of the minor loops. [ABSTRACT FROM AUTHOR]

This paper presents a clear methodology for achieving the optimum design of LCL bidirectional inductive wireless power transfer system (BIWPTS) for electric vehicle applications. The proposed strategy depends on electromagnetic field computations joined with analytical models. A 3-D finite-element model for 8-kW polarized double-D power pad was modeled, optimized, and built. Moreover, the choice of the power factor correction and the impedance matching elements was investigated. Following the proposed design considerations, a BIWPTS model was developed in MATLAB Simulink and its outcomes were compared with the theoretical model results. In addition, a small scale prototype was assembled using the same design with reduced dc voltage levels. The models were tested during charging and discharging operation, and good correlation was seen between every one of them. [ABSTRACT FROM AUTHOR]

Two types of surface-mounted permanent magnet synchronous machines (PMSMs) with the same physical dimensions but different stator core materials are comparatively analyzed, prototyped, and tested in this paper. In order to quantify the magnetization and loss characteristics of the stacked amorphous metal (AM) stator core, an experiment is conducted under different supply frequencies. Based on the data, the no-load iron losses, harmonic losses generated by the inverter-induced non-sinusoidal current harmonics, and the $d$ -axis and $q$ -axis inductances of two types of motors are comparatively analyzed by the finite-element method under different conditions and verified by experiments carried out on the two types of PMSM prototypes. The results illustrate that the AM PMSM has a characteristic of extremely low no-load iron losses, relative to the conventional silicon steel PMSM. [ABSTRACT FROM AUTHOR]

In order to better start and control the surface-mounted permanent magnet synchronous motor (SMPMSM), the inverter is widely used in the SMPMSM. However, a large number of voltage harmonics are generated by the inverter, which can directly affect motor loss and temperature. In order to analyze its influence, taking a 3 kW, 1500 r/min SMPMSM as an example, a 2-D finite-element model is established. The correctness of the model is verified by comparing the experimental data with the calculated results. First, the coupling method of the electromagnetic field and temperature field is used to analyze the electromagnetic field and the temperature field of the SMPMSM, and the data of loss and temperature rise are obtained. Based on these calculation results, the influence of voltage harmonic on SMPMSM is analyzed quantitatively. Second, when the voltage harmonics contained different harmonic orders and amplitudes, the core loss, eddy current loss, and temperature rise are studied. The variations of losses and temperature rise are obtained. Finally, the change mechanism of eddy current loss is revealed by studying the eddy current density. The conclusions of this paper can provide reliable theoretical guidance for improving the motor performance. [ABSTRACT FROM AUTHOR]

This paper investigates both the fundamental and harmonic losses of permanent magnet synchronous motor (PMSM) in conjunction with inverter losses for a wide range of switching frequencies (SFs) and different direct-axis currents (Ids) under full power range. The effects of SFs and Ids on the total losses, including fundamental loss and harmonic loss in the windings and lamination core, conduction loss, and switching loss in IGBTs, are described through analytical models. Meanwhile, the loss models of the motor are modified and validated by the 2-D finite-element analysis. Furthermore, the efficiency improvement of the overall PMSM-inverter system for different operation conditions benefits from an artificial bee colony (ABC) algorithm proposed in this paper. The optimal SF and Id, in terms of PMSM-inverter overall efficiency, are preferred for every operation point, thanks to the proposed ABC and the precise calculation of losses. Experimental results validate the proposed methodology. [ABSTRACT FROM PUBLISHER]

This paper proposes a common-mode electromagnetic interference (CM-EMI) spectrum calculation method based on double Fourier series for photovoltaic (PV) inverters with chaotic sinusoidal pulsewidth modulation (CSPWM). In this paper, the CM-EMI of a single-phase PV inverter is first analyzed, and the equivalent circuit of the CM-EMI in the single-phase PV inverter is established, then the CSPWM is employed to suppress the CM-EMI in PV inverters. Moreover, the proposed EMI spectrum calculation method based on double Fourier series is applied in evaluating the CM-EMI spectrum of the single-phase PV inverter. Finally, the simulation and experimental results validate the EMI suppression effectiveness of the CSPWM and the correctness of the proposed EMI spectrum calculation method. Therefore, the proposed EMI spectrum calculation method provides a theoretical support for CSPWM to reduce EMI. [ABSTRACT FROM AUTHOR]

High-speed permanent magnet machines, supplied by pulsewidth modulation (PWM) voltage source inverters, operate with distorted stator currents. Harmonics present in these stator currents deteriorate the machine performance by generating losses. Mostly, these losses are following the machine design using a transient finite-element model. The precise measurement of these rotor eddy-current losses is extremely difficult, hence, only a few papers provide convincing comparisons between predictions and measurements. This paper presents a fast and precise analytical approach, verified with measurements, to consider rotor losses of machines, supplied by PWM voltages, already during the design procedure. [ABSTRACT FROM AUTHOR]

Large amounts of harmonics are contained in the current as the motor is driven by pulse width modulation (PWM). Significant amounts of computing time are required to compute local flux density variation considering such current harmonics. Since the amplitudes of higher harmonics are significantly smaller than that of fundamental harmonic, flux density variations due to the higher harmonics are small, and the relationship between the field strength and flux density can be assumed to be linear. When the operating point of each element is known, flux density variations for the higher harmonics can be analyzed by linear finite-element analysis (FEA). This paper suggests a method to calculate flux density variations in the iron core while taking into considering PWM current harmonics. First, the operating point solution is obtained by nonlinear FEA, second each element is linearized. Then, the flux density for the PWM current is obtained through linear FEA. Finally, the obtained results are presented and compared with nonlinear FEA results for verification. [ABSTRACT FROM AUTHOR]

Recently, novel magnetic materials have been developed for high-efficiency and high power density electric motors. In addition, next-generation semiconductor devices, like silicon carbide (SiC) or gallium nitride (GaN), have been introduced for power converters due to their high-frequency operation. Therefore, high-frequency operation of new magnetic materials is possible when they are driven by GaN or SiC inverters. Nevertheless, iron loss characterization of magnetic materials when they are excited by high-frequency signals have not been conducted yet. This paper introduces the iron losses characterization of a magnetic material at high carrier frequency excitation using a GANFET inverter. This characterization was carried out by the experimental evaluation of iron losses at carrier frequencies from 5 to 500 kHz at different deadtimes. As a result of the measurements, iron losses seem to have a trend to increase at high carrier frequencies and large deadtimes. In addition, filtering is introduced and it seems to be an effective technique for reducing iron losses. [ABSTRACT FROM AUTHOR]

Recently, interior permanent magnet synchronous motor (IPMSM) is paying attention because of its high power density and efficiency by adopting permanent magnet. The IPMSM has two control methods: maximum torque per ampere (MTPA) control and flux weakening control. Generally, an MTPA control is applied to a continuous operating point, and in case of a startup point, input current is applied which satisfies required output torque. To control the IPMSM, the various types of inverters with current and voltage limitations are used. The motor cannot be operated if these limitations are not satisfied. This paper proposes a method to satisfy the current and voltage limitations of the inverter with two different operating points. By changing the control method of the rated operating point by a stack compensation method, the current and voltage limitations of the inverter can be satisfied at a startup operating point, where the input current in MTPA control at the continuous operating point cannot be satisfied. The proposed method is verified by a 2-D finite element analysis. [ABSTRACT FROM AUTHOR]

This paper provides new magnetic and electrical design guidelines for an integrated motor-drive system. Two significant design factors including the electric and magnetic loadings are targeted to address the issues associated with the combination of the motor and inverter performances. A set of new constraints is also introduced in terms of the magnetic, electrical and thermal limits of a field oriented controlled permanent magnet (PM) motor to highlight the corresponding design challenges. Moreover, the demagnetization proximity limit is incorporated to ensure a reliable and safe operation of the PM material. The results show that the magnetic and electrical requirements of an optimum integrated system are totally different from the optimum performances of either side of the system, i.e., the motor or the inverter. Finally, an efficiency/robustness trade-off is proposed and applied to the investigated motor-drive system to return a reliable and efficient design. [ABSTRACT FROM AUTHOR]

This paper proposes and implements a novel multi-frequency multi-power wireless power transfer (MFMP-WPT) system based on one single transmitter for simultaneously and compatibly energizing multi-standard receivers. Generally, implementing a multi-frequency WPT often requires a compromise in system complexity, control difficulty, switching frequency, or transmission efficiency. By using only a single transmitter with an artful inverter topology, the proposed MFMP-WPT system can effectively achieve multi-frequency multi-magnitude superposition and switching frequency reduction while maintaining the control fitness and convenience of square-wave generation with 50% duty cycle. Moreover, by switching at the fundamental frequency in a range of 80–130 kHz, the single transmitter becomes competent for one-to-many MFMP-WPT operation for diverse wireless power on-demands. Consequently, the fundamental and high-order harmonic wireless energies with multiple power levels can be, respectively, picked up by the multi-standard receivers, depending on their energy requirements. The experimental transmission and system efficiencies can reach 81.57% and 64.74% under MFMP-WPT, respectively. Theoretical analysis, computer simulation, and experimental results are provided to verify the feasibility of the proposed MFMP-WPT system. [ABSTRACT FROM AUTHOR]

This paper proposes a novel winding scheme to generate an additional sub-harmonic magneto-motive force (SH-MMF) component for the brushless (BL) operation of a wound-field synchronous machine. The existing SH generation schemes for BL operation use a dual inverter or a single inverter with asymmetrical winding and low slot fill factor in half of the stator. The proposed scheme comprises a single inverter with symmetrical stator winding distribution and the same fill factor for all stator slots. The generated additional SH-MMF component in the proposed scheme is induced in the harmonic winding wound on the machine rotor. A rotating bridge rectifier mounted on the rotor periphery connects the rotor harmonic winding with the rotor field winding, and rectified dc is supplied to the rotor field winding. The 2-D finite-element analysis (FEA) was carried out to analyze the principle, and the FEA predictions were experimentally validated. [ABSTRACT FROM AUTHOR]

This paper proposes and analyzes the design philosophies of the single-phase main exciter (ME) for an aircraft wound-rotor synchronous machine and investigates its operating characteristics in both generating and starting modes. The fundamental structure and starting–generating system are discussed. The load features of single-phase ME are summarized. The ME has the characteristics of linear current amplifier and approximately constant current source the generating mode, which can be used in the wide range of working temperature. Detailed waveforms and finite-element analysis verify that excitation current $I_{\mathrm {ef}}$ is almost irrelevant to speed but in direct proportion to frequency in the starting mode. Besides, simulated data indicate that the energy transferring efficiency between ME stator and rotor can reach about 55% by the single-phase ac excitation method. Finally, the experimental verification is carried out, and the simulated and experimental data and waveforms of single-phase ME agree well with each other. [ABSTRACT FROM AUTHOR]

This paper introduces the periodic carrier frequency modulation (PCFM) for permanent magnet synchronous motor (PMSM) drive systems so as to reduce the low-frequency electromagnetic interference (EMI). PMSMs are widely used in many applications and they are usually fed by pulsewidth modulation (PWM) inverters. The EMI of PMSM, which results from the switch of power device, generates undesirable effects on the control system. Therefore, it is of importance to reduce the EMI of PMSM. The common mode (CM) conducted EMI model of the PMSM drive system is constructed to investigate the CM voltage. The simulations and experiments of PMSM fed by the fixed frequency PWM (FFPWM) and PCFM are implemented to analyze the CM conducted EMI. The CM EMI spectra of PMSM fed by the FFPWM and PCFM with different spreading frequency widths are compared to explore the influence of PCFM on the CM conducted EMI. The regular patterns on PCFM in reducing the CM conducted EMI of PMSM drive systems are revealed. [ABSTRACT FROM AUTHOR]

This paper presents a new concept for brushless excitation of a wound rotor synchronous machine (WRSM) based on the generation and utilization of a subharmonic component of the stator magnetomotive force (MMF). In this method, a dual inverter topology for the stator winding is proposed. The idea is to generate and utilize an additional subharmonic stator MMF component along with the fundamental component. The rotor carries two different windings: 1) excitation winding and 2) field winding. The subharmonic component induces voltage in the excitation winding and feeds the field winding through a rotating rectifier on the rotor. A 2-D finite-element analysis was performed to analyze and verify the proposed brushless WRSM. [ABSTRACT FROM AUTHOR]

This paper proposes a novel parallel computation technique in the time domain for use in finite-element analyses of time-periodic nonlinear magnetic fields. The proposed method is based on converting problems from single phase to multiple phase and the polyphase time-periodic explicit error correction method. Numerical results that demonstrate its effectiveness are presented. [ABSTRACT FROM PUBLISHER]

The infinite edge element method (IEEM) has been proposed as an effective method for efficiently handling open boundary region, i.e., the air region. In this paper, we present a newly defined infinite element radiated from a reference plane (RPL), and propose the combination method using various infinite element configurations, such as radiated configurations from a reference point, a reference line, and an RPL. By using the proposed hybrid method, we can drastically decrease the number of ill-shaped infinite elements and improve the computational accuracy and convergence characteristics in comparison with the conventional IEEM, especially in the case of flattened analysis models. [ABSTRACT FROM PUBLISHER]

This paper investigates the effects of a load on the iron loss of an electrical sheet using a ring specimen with a secondary coil under pulse width modulation inverter excitation. In this experiment, the resistance load is connected to the secondary coil to simulate the motor load. To investigate the iron loss under load, we derive two methods to calculate the iron loss: the current difference method (CDM) and the power difference method (PDM). In the CDM, the iron loss is determined using the differential between the input current from the power amplifier to the specimen and the output current from the specimen to the load and voltage of the B-coil. In the PDM, the iron loss is derived using the differential between the input and output power. The iron loss calculated using the CDM and PDM agrees well when the secondary coil is open circuit, whereas the difference in the iron loss between the CDM and PDM increases as the resistance of the load decreases, especially when the carrier frequency is high. [ABSTRACT FROM AUTHOR]

We calculate an iron loss attributed to semiconductors ON-voltages in an inverter circuit and reveal influence rate of the ON-voltages on whole iron loss. In our previous work, it has been revealed by inverter excitation that the ON-voltages make minor loops in magnetic hysteresis of magnetic material and the loops affect iron loss characteristics. In this paper, it is investigated by a factor analysis how much the on-voltage has an influence on iron loss, quantitatively. We separate whole iron loss caused in a non-oriented electrical steel sheet into three losses: loss by the ON-voltage, loss by fundamental component, and loss by inverter carrier. The rates of these losses are evaluated under several conditions of single-phase pulse width modulation inverter excitation, and the results show that the proportion of loss by ON-voltages is up to around 10% depending on inverter excitation parameter: fundamental frequency, carrier frequency, modulation index, and magnetic flux density. [ABSTRACT FROM PUBLISHER]

In this paper, the investigation is focused on the iron loss prediction for electrical machines fed by low switching frequency inverter. An improved iron loss model is developed after reviewing various existing iron loss models considering pulse-width modulation (PWM) influence. In order to validate the improved iron loss model, iron loss tests are carried out on an electrical machine. The predicted iron loss results match well with the measured results, which shows that the improved iron loss model is able to predict iron loss in electrical machine fed by an inverter. The comparison between the predicted iron losses with and without considering the PWM influence shows that the iron loss can be significantly increased due to the influence of PWM, especially when the switching frequency is low. [ABSTRACT FROM AUTHOR]

The deadbeat control (DBC) can track current reference closely, depending on the model of a linear induction machine (LIM). However, the DBC has to consider both the voltage and current constraints for staying in the safe working region of LIM, when calculating the input voltage vector of LIM. To solve such a challenge, one improved DBC with an iterative algorithm is proposed in this paper to solve the voltage and current constraints problem in the traditional DBC. Finally, the improved DBC is applied to 3 kW arc induction motors to verify its effectiveness. [ABSTRACT FROM AUTHOR]

In this paper, a high-efficiency wireless power transfer (WPT) and force transfer system for a micro-robot is proposed. Two-coil systems are employed to power the micro-robot. The two-coil parts are ac and dc, and each consists of an external source and a load coil inside the micro-robot. In the ac coil part, the external source coil generates a time-varying magnetic field that is received by the ac load coil in the micro-robot as electrical energy. In the dc coil part, the external source coil is used as an electromagnet, which is used to generate propulsion force for the micro-robot. Through the proposed system, both the efficiency of electrical energy transfer and the generation of propulsion force can be significantly improved. The feasibility of the proposed approach was verified through simulation and experimentation results. [ABSTRACT FROM AUTHOR]

This paper proposes a novel cableless magnetic actuator with a new propulsion module that exhibits a very high thrusting force and is capable of locomotion in a thin pipe by means of a new motion principle. The magnetic actuator is moved according to the vibration amplitude and elastic energy of a mass-spring system due to mechanical resonance energy. The proposed actuator contains an electrical inverter that directly transforms dc from button batteries into ac. The electrical dc–ac inverter incorporates a mass-spring system, a reed switch, and a curved permanent magnet that switches under electromagnetic force. Experimental results reveal that the actuator is able to move upward at a speed of 52 mm/s when powered by 10-button batteries and pulling a load mass of 10 g. [ABSTRACT FROM AUTHOR]

This paper presents the control method that inverter output keeps to linear to reference voltage of Synchronous Reluctance Motor (SynRM) using DC Link voltage Synthesis. This method is reduced torque ripple considering parameters with magnetic saturation. To estimate parameters of inductances for SynRM, the proposed method uses recursive least square (RLS) estimation algorithm. The estimated inductances are used for calculating torque and DC link voltage. The Inverter output voltage cannot be displayed to linear about inverter reference voltage if Real DC Link voltage is different from DC Link voltage of PWM amplitude. Also, the over-modulation is linearity broken if reference voltage is out of range. Torque ripple generates the vibration and noise of a motor. This paper proposes the control method so that the torque ripple decreases and the linearity of inverter output keeps using the DC Link voltage Synthesis. The proposed control method is verified by computer simulation and experiment. [ABSTRACT FROM AUTHOR]

This paper introduces a novel topology for generating a spatial third-harmonic current component to excite the rotor field winding of a wound rotor synchronous machine to achieve brushless operation. In this topology, each of the three-phase windings on the stator is connected with a switch in parallel. In particular, two antiparallel thyristors are used to switch during positive and negative half cycles. Two windings are mounted on the rotor of the machine: 1) the harmonic winding and 2) the field winding. Zero-sequence currents are generated, when the switches are closed near zero crossing for a short time interval. Consecutive operation of the switches creates an additional spatial third-harmonic current pulsating in the stator winding. The number of poles of the stator winding and the field winding is the same (four-poles in this case) to intercept the torque generation component of the air-gap flux, whereas, the number of poles of the harmonic windings is adjusted (12-poles in this case) to intercept the harmonic component of the air-gap flux and develop voltage across the harmonic windings. Harmonic voltage is rectified through a rotating rectifier to feed dc current to the field windings. Results verify the proposed topology simulated by a 2-D finite-element method. [ABSTRACT FROM PUBLISHER]

This paper investigates the harmonic losses and torque ripple of a surface permanent magnet (SPM) motor driven by pulsewidth-modulated inverter for a wide range of switching frequencies (SFs), using a 2-D nonlinear time stepping finite-element model, including strand conductors proximity effect, coupled with an appropriate external electric circuit. Such a method enables the estimation of torque ripple as well as the accurate prediction of the eddy current losses in the windings, lamination core, and PMs, respectively. Moreover, the total power losses of the inverter are calculated via analytical techniques. The analysis undertaken proposes an optimum SF, in terms of overall drive system efficiency and torque quality, considering multiple operating conditions. The simulated results are validated by measurements on a prototype SPM actuator, illustrating that the SF plays an important role on SPM motor drive applications. [ABSTRACT FROM PUBLISHER]

In this paper, an integrated motor-drive and battery-charging (IMB) system with a doubly salient electromagnetic machine (DSEM) is proposed to be implemented for electric vehicles. In the driving mode, the front-end dc/dc converter is employed to boost the battery voltage to improve the speed range and acceleration ability of the DSEM. The field windings distribution of a 12/10-pole DSEM is arranged for the constant self-inductance, and adopted as the inductance of the front-end dc/dc converter to eliminate the traditional filter inductance and excitation loss of the machine. In the charging mode, the windings of DSEM could be exploited as the filter inductances to obtain the unity power factor operation and constant current charging ability. The simulations and experiments have been accomplished to verify the feasibility of the independent field current control method for the proposed IMB system. [ABSTRACT FROM AUTHOR]

The inspection of pipes used in nuclear power and chemical plants is very important. A cableless actuator capable of inspection in narrow pipes has not yet been developed. This paper proposes a novel cableless magnetic actuator system with a new type of electrical dc–ac inverter that provides a very high-thrust force. The motive properties of the cableless magnetic actuator were investigated experimentally for two different dc–ac inverters. The experimental results indicate that the proposed actuator is able to move upward at a speed of 455.2 mm/s by the power provided by ten button batteries under no-load conditions. Based on the experimental results, additional devices of a CCD camera, two LED lights, a transmitter with an antenna, and various types of batteries were placed on the cableless magnetic actuator and then carried out a driving test. The inspection of thin pipe can be accomplished using the proposed cableless magnetic actuator system, a 2.4 GHz receiver, and a PC with video-capture software as the only additional equipment. [ABSTRACT FROM AUTHOR]

To evaluate how magnetic properties of magnetic materials are influenced by power semiconductor properties in an inverter circuit, we propose and test a new numerical calculation method. This method combines an electrical circuit analysis for current–voltage properties of power semiconductors with a magnetic analysis based on a magnetic hysteresis model. Previous measurements on an inverter show that magnetic properties, such as B–H curves (B is the magnetic flux density and H is the magnetic field intensity) and iron losses, are affected by ON-voltages of power semiconductors. Those measurements motivate this paper. The magnetic hysteresis model used here is a novel approach that is based on physical thermodynamics theory and can capture the essence of physical magnetic phenomena. Calculations with the proposed method show that measured minor loops in B–H curves are well represented and calculated voltage waveforms properly capture ON-voltage effects. [ABSTRACT FROM AUTHOR]

An automatic shape optimization procedure that estimates the inverter carrier harmonic losses generated at cores and magnets has been developed in order to improve the performance of interior permanent magnet motors used for variable speed/load applications. In the proposed procedure, an electromagnetic field analysis coupled with armature voltage equation is iteratively carried out at each rotor shape. The input of this analysis is the theoretical inverter voltage, which is determined by both the rotor shape and the driving conditions of the motor. The proposed procedure is applied to a 100 kW-class interior permanent magnet motor, in which the carrier harmonic losses become dominant under frequent driving conditions. It is clarified that the carrier harmonic losses can be reduced by more than 10%, whereas the other important characteristics are not deteriorated. [ABSTRACT FROM AUTHOR]

To reduce power consumption of CPU, nonvolatile cache memory has been expected by replacing conventional volatile cache memory based on SRAM. This paper describes nonvolatile cache memory hierarchy design using fast and low-power perpendicular (FL-p-) STT-MRAM. For L3, L2 and L1 cache, 1T-1MTJ with FL-p-STT-MRAM, 6T-2MTJ, and short write pulse based 6T-2MTJ having voltage-induced magnetization switching has been presented for the most suitable combination for the cache memory. [ABSTRACT FROM AUTHOR]

An electromagnetic–state space–wavelet neural network modeling environment is presented and used for the characterization of high-speed synchronous generators during out-of-phase operation in distributed generation (DG) of a microgrid. This mode of operation may result in stresses in the network or the failure of the high-speed generators. The approach is validated, by comparing simulation results with test data, and its effectiveness is established in terms of accuracy and fast response. In addition, it is demonstrated in a case study involving two DG units in a microgrid that the stresses and damages are minimized in an out-of-phase DG unit when connected to the grid through an inverter. [ABSTRACT FROM AUTHOR]

In this paper a 1-bit full adder realized in perpendicular nanomagnetic logic (pNML) is presented for the first time. The theory of NML with perpendicular magnetic anisotropy is introduced illustrating the great benefit of the universal majority decision. The working principle of complex logic circuits is experimentally demonstrated utilizing the presented full adder. Partial focused ion beam irradiation is used to control the anisotropy locally and tailor the magnetic behavior of the nanomagnets. A full adder structure consisting of 3 majority gates and 4 inverters is realized on an area of 17 um^2. Global, alternating field pulses with constant amplitude are used as power clock. MFM measurements demonstrate the functionality of the structure and the validity of the introduced theory. [ABSTRACT FROM AUTHOR]

In hybrid and electric vehicles, passengers sit very close to an electric system of significant power, which means that they may be subjected to high electromagnetic fields. The hazards of long-term exposure to these fields must be taken into account when designing electric vehicles and their components. Among all the electric devices present in the power train, the electronic converter is the most difficult to analyze, given that it works with different frequencies. In this paper, a methodology to evaluate the magnetic field created by a power electronics converter is proposed. After a brief overview of the recommendations of electromagnetic fields exposure, the magnetic field produced by an inverter is analyzed using finite element techniques. The results obtained are compared to laboratory measurements, taken from a real inverter, in order to validate the model. Finally, results are used to draw some conclusions regarding vehicle design criteria and magnetic shielding efficiency. [ABSTRACT FROM AUTHOR]

In this article, a special magnetic coupler for three-coil wireless power transfer (WPT) is proposed to eliminate the mutual inductance between the source coil and the receiver coil, which can significantly improve the design freedom. Specifically, unipolar Q coil, mixed QDD coil, and bipolar DD coil are designed for the source coil, the transmitter coil ($\text{T}_{\mathrm {X}}$), and the receiver coil ($\text{R}_{\mathrm {X}}$), respectively. By making use of unipolar coils and bipolar coils, this structure magnetically decouples the receiver coil from the source coil. Meanwhile, under different lateral misalignment conditions, this new coupler facilitates maintaining high efficiency. A laboratory prototype has been constructed to validate the proposed structure, demonstrating that the proposed structure can realize inherent characteristics, enhance misalignment tolerance, and energy transfer. The potential applications are EV systems, but this design can be generalizable to other three-coil systems. [ABSTRACT FROM AUTHOR]

A consistent and computationally efficient finite-element model for the simulation of the steady-state operation of surface-mounted permanent magnet brushless dc motors driven from quasi-square wave inverters is presented. The methodology combines the magnetostatic finite-element and the steady-state time-periodic circuit models with time averaging. A weak field-circuit coupling is established through the effective constant current and lumped parameters estimated at various loading conditions. The performance characteristics, determined via the proposed model for two different motors, are comparable with those obtained from the comprehensive time-stepping finite-element model, with the execution time being approximately a hundred times shorter for the former. [ABSTRACT FROM AUTHOR]

The characteristics of MW-class high speed induction motors are analyzed by 3-D finite element methods. First, several approximations are applied to the analysis in order to reduce the computation time without the deterioration of accuracy. Then, the calculated characteristics are compared with the experimental results in order to verify the proposed method. Finally, the loss generation mechanism of the motor is revealed by analyzing the harmonic electromagnetic fields. It is clarified that the combination of the 2-D and the one rotor slot 3-D finite element methods is suitable for the analysis of the motors. By using this method, the largest harmonic loss component of the motor is successfully specified. [ABSTRACT FROM PUBLISHER]

We present a new brushless DC motor (BDCM) design based on a model elaborated from a finite-element method associated to controller circuit equations represented in a Matlab-Simulink environment. The simulation model takes into account the commutation period effect and is based on the true system design implementation. The simulation results show that there is an effect between this commutation (a major source of torque ripple) and appropriate permanent-magnet segmentation design, particularly when the angle of advance between the back-electromotive force (EMF) and the current is adequately set. Current control strategies are found limited and may require complex implementation. Concentration on back-EMF and ultimately on permanent-magnet design are interesting aspects of torque ripple as well as rotor losses over wide speed range. After validation of the simulation model using an experimental kit set for the purpose, we perform an optimization procedure based on an indirect coupled field circuit approach that has led to an optimal design for which the torque ripple is minimal (less than 6%). An analytical design provided support for the study. The new design shows a lower cogging torque. Overall, the new design helps to provide a low-cost BDCM system for many applications using a simple square wave circuit controller. [ABSTRACT FROM PUBLISHER]

For linear systems excited with sinusoidal constraints, an exact dynamical modelling can be performed with a phasor (complex number) approach. For nonlinear systems (exhibiting saturation, hysteresis and higher harmonics), a time stepping model is very time consuming. A method to model such nonlinear systems with an approximated phasor approach is presented. Determination of equivalent material characteristics is discussed and applications are given. [ABSTRACT FROM PUBLISHER]