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Permanent magnet synchronous machines (PMSMs) have been widely used in various applications such as robotics, electric vehicles, and aerospace due to their fast dynamic response, high-power/torque density, and high efficiency. These features make them attractive candidates for aeronautical applications, where the weight and volume of onboard systems are critically important. This paper aims to provide an overview of recent developments in PMSMs. Key design considerations for aeronautical PMSMs across different applications are highlighted based on the analysis of industrial cases and research literature. Additionally, emerging techniques that are vital in enhancing the performance of aeronautical PMSMs are discussed. [ABSTRACT FROM AUTHOR]

The high-performance vector control technology of permanent magnet synchronous machines (PMSMs) relies on high-precision rotor position. The Hall-effect sensor has the advantages of low cost, simple installation, and strong anti-interference ability. However, it can only provide six discrete rotor angles in an electrical cycle, which makes high-precision vector control of PMSMs difficult. Hence, to obtain the necessary rotor position of PMSMs, a rotor position fitting method combining the Hall signal and machine flux information is proposed. Firstly, the rotor position signal output by the Hall-effect sensors is used to calibrate and update the stator flux obtained under pure integration. Then, based on the corrected stator flux and its relationship with current and angle, the rotor position and speed are obtained. Experimental verification shows that the rotor position observer combining Hall signal and flux information can reduce the initial value bias and integral drift caused by traditional average speed method hysteresis and pure integration method calculation of flux and can quickly and accurately track and estimate the rotor position, achieving high-performance vector control of PMSMs. [ABSTRACT FROM AUTHOR]

In this paper, novel position sensorless state estimators with improved robustness to permanent magnet (PM) flux linkage variations in permanent magnet synchronous machines (PMSMs) are presented. Unlike state estimators using conventional infinite inertia or electromechanical models, the estimators presented here can also estimate the PM flux linkage, so they are not sensitive to its uncertainty. For each models used for state estimation, a detailed observability study is presented. Due to the nonlinear models, extended and unscented Kalman filter algorithms are used for the implementation. To compare the sensitivity of conventional and proposed state estimators to uncertainty in electrical parameters, numerical simulations are carried out. In addition, the computational burden of the estimators is compared by real-time execution.

The motor parameters of permanent magnet synchronous motor (PMSM) can be mismatched in operation due to temperature variations and magnetic saturation. The parameter mismatch leads to a significant decrease in the robustness of traditional deadbeat predictive current control (DPCC), which leads to issues such as current static error and motor vibration noise. In this paper, a model-free predictive current control (MFPCC) method based on an improved sliding mode disturbance observer (SMDO) was proposed. The method estimated the total disturbance of the system using the improved SMDO, which could effectively suppress sliding mode chattering and accelerate the convergence speed of current errors. Subsequently, the predicted control voltage was calculated using a hyper-local model and compensated for the time delay. The experimental results demonstrated that the improved MFPCC-SMDO method generated lower motor noise compared to the traditional DPCC method when the controller's inductance parameters are mismatched. [ABSTRACT FROM AUTHOR]

This article aims to propose a highly reliable permanent magnet synchronous machine (PMSM) for flywheel energy-storage systems. Flywheel energy-storage systems are large-capacity energy storage technologies suitable for the short-term storage of electrical energy. PMSMs have been used in the flywheel energy-storage systems due to their advantages. One of the key requirements for PMSMs in flywheel energy-storage systems is high reliability. A double redundant winding structure is adopted to ensure fault-tolerant operation of the PMSM. The stator is designed with auxiliary teeth to reduce the short-circuit current. Moreover, the number of slots and poles is determined to ensure the winding factor, heat dissipation, and reduce losses. Moreover, the dual three-phase stator winding structure and auxiliary teeth are adopted on the PMSM to improve reliability. Afterward, the electromagnetic performance is analyzed, and the mechanical stress is investigated to ensure mechanical strength. Finally, a prototype is built and tested to verify the theoretical analysis and performance of the PMSM. [ABSTRACT FROM AUTHOR]

In electrified vehicles, the masking noise behavior of internal combustion engines is absent, making the tonal excitation of the electric machine particularly noticeable in vehicle acoustics, which is perceived as disturbing by consumers. Due to manufacturing tolerances, the tonal NVH characteristics of the electric machine are significantly influenced at wide frequency ranges. This paper presents a systematic exploration of the influence of static eccentricity as one manufacturing tolerance on the NVH behavior of Permanent Magnet Synchronous Machines (PMSMs). The study utilizes a novel test bench setup enabling isolated variations in static eccentricity of up to 0.2 mm in one PMSM. Comparative analysis of acceleration signals reveals significant variations in the dominance of excitation orders with different eccentricity states, impacting critical operating points and dominant frequency rages of the electric machine. Despite experimentation, no linear correlation is observed between increased eccentricity and changes in acceleration behavior. Manufacturing eccentricity and deviations in rotor magnetization are discussed as potential contributors to the observed effects. The findings emphasize static eccentricity as a critical parameter in NVH optimization, particularly in electrified powertrains. However, the results indicate that further investigations are needed to explore the influence of eccentricities and magnetization deviations on NVH behavior comprehensively. [ABSTRACT FROM AUTHOR]

In this paper, novel position sensorless state estimators with improved robustness to permanent magnet (PM) flux linkage variations in permanent magnet synchronous machines (PMSMs) are presented. Unlike state estimators using conventional infinite inertia or electromechanical models, the estimators presented here can also estimate the PM flux linkage, so they are not sensitive to its uncertainty. For each models used for state estimation, a detailed observability study is presented. Due to the nonlinear models, extended and unscented Kalman filter algorithms are used for the implementation. To compare the sensitivity of conventional and proposed state estimators to uncertainty in electrical parameters, numerical simulations are carried out. In addition, the computational burden of the estimators is compared by real-time execution. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The slender shape of the driving machine leads to a low rigidity and large axial thermal elongation of the motorized spindle, which deteriorates the machining precision. To solve these problems and pursue a more compact size, this paper investigates the feasibility of using a tooth-coil permanent magnet synchronous machine in a high-speed spindle, replacing the original motor that has the conventional distributed winding. Comprehensive performance and behavior of machines with distributed and tooth-coil windings are comparatively analyzed, in terms of the essential torque ripples, winding inductances, electromagnetic losses, rotor integrity, and heat dissipation of the spindle. Thorough numerical simulation results indicate that the newly designed tooth-coil winding solution shows significant advantages over the original design, regarding high rotor rigidity, low torque ripples, reduced electromagnetic losses, and reduced shaft thermal elongation. Prototypes and test setups for the high-speed tooth-coil machine are built, where preliminary measurements are carried out to validate the analysis results and system design. [ABSTRACT FROM AUTHOR]

In this paper, the operation of an inertial flywheel storage system based on the permanent magnet synchronous machine (PMSM) is presented. The contribution in this work lies in the optimization of the exchanged power between the storage system and the grid. The related speed reference is determinate from the desired power through a tracking algorithm known as reference power point tracking (RPPT). This one permit to achieve a desired grid-side power. That is ensured by a simple algorithm which needs only the measurements of grid-side power and reference power. This algorithm is robust because it doesn't depend to system parameters, and to an increased reliability. The problem of variable losses once several grid connected-storage systems are considered is then avoided. This will serve grid operator to adjust efficiently the grid frequency. The last point is the main advantage of the proposed method compared with others ones that use machine-side power measurements for speed reference synthetizing. The studied system is implemented under DSPACE type RTI1005. The rotation speed of the permanent magnet machine and the power exchanged between the electrical grid and the inertial storage system follow their reference with an error of 0.032% and 0.83% respectively. The simulation and experimental results presented show the effectiveness of the tracking algorithm. [ABSTRACT FROM AUTHOR]

The DC motor is being rapidly replaced in the industry by the permanent magnet synchronous motor (PMSM), which has a number of benefits over it. Nonlinear equations are used to describe the dynamics of the PMSM. It is susceptible to unidentified external disturbances (load), and its properties change over time. These constraints make it more difficult to exercise control. To overcome the non-linearities and the aforementioned shortcomings, non-linear controls are necessary. This manuscript refers to the development of a sturdy high-caliber position tracking controller that incorporates integral action for PMSM. A predictive control law for the speed loop is established, combined with the backstepping control law for the inner loop. The overall strategy can be divided into two distinct elements. The initial stage involves the derivation of a reference electromagnetic torque computed through the generalized non-linear predictive control method. Subsequently, the controller law is formulated utilizing the robust backstepping control technique. One of the cardinal merits of this method lies in its exemption from the requirement of measuring and observing the external disturbances and parametric uncertainties. The efficacy of this cutting-edge control approach is rigorously evaluated in simulation with MATLAB/Simulink environment and experimentally using OPAL-RT, under diverse operating conditions. The findings demonstrate steadfast resilience amidst external disruptions and adjustments to parameters, while ensuring swift convergence, a testament to its robustness and reliability.

Permanent magnet synchronous machine (PMSM) has proven to be a more economical traction drive system for electric vehicle (EV) applications owing to increased efficiency and high-power density. However, the drive system requires more efficient control schemes to deliver better dynamic performance irrespective of dynamic changes in the motor speed, machine parameters and disturbances. Hence, to tackle the dynamic changes, to enhance the wider operating speed, to achieve precise speed tracking capability, and improved efficiency, a novel control algorithm for the PMSM based EV is proposed in this paper. The control algorithm is implemented by adopting the merits of conventional proportional resonance (PR) and proportional integral (PI) controller. The proposed control strategy is designed with an outer PI speed regulator and the inner enhanced PR (EPR) current regulator. The uniqueness of the proposed EPR controller is that the controller is designed to damp the torsional mode oscillation owing to dynamic changes such as speed and torque regulation evading the additional control loop. The effectiveness of the control scheme is tested in MATLAB Simulink and hardware-in-loop (HIL) real time simulator RT5700. To validate the effectiveness of the proposed control scheme the results are compared with the conventional control schemes. The results presented show that the proposed control technique successfully enhances the static and dynamic performance, and resilience of the EV system. Also, the proposed scheme significantly reduces the flux ripples, torque ripples, current jitter, peak overshoot, undershoot compared to the conventional current controllers.

The increasing automation in the design process of electrical machines for vehicles generates huge amounts of data, leading to a growing interest in using machine learning for faster predictions and optimization. This paper presents an innovative approach to simultaneously model and optimize different geometries of electrical machines. Unlike previous methods that rely on specific design variables or pixel-based representations, this approach is based on a flexible vector graphic representation that can easily be applied to any electrical machine configuration. This also sidesteps the problem of scalar-based design representation and, unlike pixel-based representation, can be directly imported into finite element simulations for validation. To speed up the optimization process, we transform the corresponding problem into a lower-dimensional latent space learned by a variational autoencoder. This is trained on a total of 6839 different 2D geometries of electrical machines, which were exported from the finite element simulation into the standardized scalable vector graphics format. The optimization results show that a sharp boundary is formed in the combined Pareto front of different rotor topologies. The validation results demonstrate that this novel method delivers results comparable to those of current techniques.

In order to address the challenges of high loss density, difficult heat dissipation, and irreversible demagnetization in high temperature of high-speed permanent magnet machine, an innovative cooling structure with axial ventilation and self-cooling rotor is proposed to enhance temperature distribution. The cooling efficiency of the cooling structure is defined, and the influence of the rotor vent on the electromagnetic and air friction loss is analyzed. The governing equation for the fluid flow in a rotating pipe is derived from a fluid model analysis of a ventilation hole rotating at any angle to the axis of rotation. The calculated results are validated against the results obtained from computational fluid dynamics. The sensitivity of rotor cooling performance to various control factors using the variance index method. Subsequently, the cooling structure was enhanced based on the findings of the analysis. The calculation results indicate that the heat dissipation effect of the axial ventilation self-cooled rotor has decreased by 4.17 °C compared to before the improvement. The temperature rise experiment verified the accuracy of temperature calculation and the effectiveness of the cooling structure, providing strong support for the design of axial self-ventilation cooling system for high-speed machines.

Permanent magnet synchronous machines (PMSMs) have been widely used in various applications such as robotics, electric vehicles, and aerospace due to their fast dynamic response, high-power/torque density, and high efficiency. These features make them attractive candidates for aeronautical applications, where the weight and volume of onboard systems are critically important. This paper aims to provide an overview of recent developments in PMSMs. Key design considerations for aeronautical PMSMs across different applications are highlighted based on the analysis of industrial cases and research literature. Additionally, emerging techniques that are vital in enhancing the performance of aeronautical PMSMs are discussed.

The high-performance vector control technology of permanent magnet synchronous machines (PMSMs) relies on high-precision rotor position. The Hall-effect sensor has the advantages of low cost, simple installation, and strong anti-interference ability. However, it can only provide six discrete rotor angles in an electrical cycle, which makes high-precision vector control of PMSMs difficult. Hence, to obtain the necessary rotor position of PMSMs, a rotor position fitting method combining the Hall signal and machine flux information is proposed. Firstly, the rotor position signal output by the Hall-effect sensors is used to calibrate and update the stator flux obtained under pure integration. Then, based on the corrected stator flux and its relationship with current and angle, the rotor position and speed are obtained. Experimental verification shows that the rotor position observer combining Hall signal and flux information can reduce the initial value bias and integral drift caused by traditional average speed method hysteresis and pure integration method calculation of flux and can quickly and accurately track and estimate the rotor position, achieving high-performance vector control of PMSMs.

This paper proposes a design methodology for power-dense and high-efficient electrohydraulic units (EHUs) that can be used to select design specifications for the electric machine (EM) for a given hydraulic machine (HM) architecture. The proposed method evaluates EHU performance considering both electric and hydraulic power losses. The compactness of the EHU is achieved by integrating an axial piston unit as HM inside a permanent magnet EM. The paper provides a sensitivity analysis for important EHU design specifications and discusses the best choices for reducing total mass and energy loss. The study finds that greater aspect ratios promote power-to-weight ratio, while high voltage promotes energy efficiency. The paper also discusses the choice of fixed versus variable displacement HMs, with the finding that a variable displacement unit helps address low efficiency limits of low-speed operation, particularly for low voltage electric machines. Additionally, variable displacement can also be used to reduce EM losses when meeting a flow-pressure demand. The proposed methodology has applications in fields such as off-road vehicles. [ABSTRACT FROM AUTHOR]

This paper applies the identified parameters of permanent magnet synchronous machines (PMSMs) for the maximum torque per ampere control (MTPA) under magnetic saturation. The variation in magnet flux with current is determined using a position offset approach while the variation in q-axis inductance with the current is estimated from the d-axis voltage equation afterward. In addition, the d-axis inductance is estimated at standstill by the injection of a small amplitude of high frequency d-axis current. The curve-fitted results of estimated parameters under different saturation conditions are then employed to aid the derivation of MTPA control law. The proposed method is experimentally verified on two prototype PMSMs. Experimental results show that compared with conventional MTPA schemes using fixed values of magnetic parameters, the proposed method can increase maximum output torque by 2.1% and 3.2% on two prototype PMSMs, respectively. [ABSTRACT FROM AUTHOR]

The paper presents a synthetic loading method (SLM) for the power loss determination in the multiphase electrical machine over a wide operating range. The conventional power loss determination requires a mechanical coupling of the machine under test with a sufficiently large active brake which complicates the measurement process and makes it more expensive. MSO is particularly suitable in the multiphase machines with an even number of three-phase winding sets. SLM is applied on a six-phase synchronous machine with interior permanent magnets and two three-phase winding sets fed by two three-phase inverters with a common DC link. The motoring set generates a positive and the generator set a negative torque. The motor and generator winding sets exchange the mechanical power in the air gap. The power is then recirculated back to the motoring set via a common DC link. Only the power needed to cover the losses of the drive flows from the DC circuit. The machine power losses are determined from the measurement of the input power of the two winding sets thus avoiding a mechanical loading of the shaft with additional machinery. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article aims to propose a highly reliable permanent magnet synchronous machine (PMSM) for flywheel energy-storage systems. Flywheel energy-storage systems are large-capacity energy storage technologies suitable for the short-term storage of electrical energy. PMSMs have been used in the flywheel energy-storage systems due to their advantages. One of the key requirements for PMSMs in flywheel energy-storage systems is high reliability. A double redundant winding structure is adopted to ensure fault-tolerant operation of the PMSM. The stator is designed with auxiliary teeth to reduce the short-circuit current. Moreover, the number of slots and poles is determined to ensure the winding factor, heat dissipation, and reduce losses. Moreover, the dual three-phase stator winding structure and auxiliary teeth are adopted on the PMSM to improve reliability. Afterward, the electromagnetic performance is analyzed, and the mechanical stress is investigated to ensure mechanical strength. Finally, a prototype is built and tested to verify the theoretical analysis and performance of the PMSM.

In electrified vehicles, the masking noise behavior of internal combustion engines is absent, making the tonal excitation of the electric machine particularly noticeable in vehicle acoustics, which is perceived as disturbing by consumers. Due to manufacturing tolerances, the tonal NVH characteristics of the electric machine are significantly influenced at wide frequency ranges. This paper presents a systematic exploration of the influence of static eccentricity as one manufacturing tolerance on the NVH behavior of Permanent Magnet Synchronous Machines (PMSMs). The study utilizes a novel test bench setup enabling isolated variations in static eccentricity of up to 0.2 mm in one PMSM. Comparative analysis of acceleration signals reveals significant variations in the dominance of excitation orders with different eccentricity states, impacting critical operating points and dominant frequency rages of the electric machine. Despite experimentation, no linear correlation is observed between increased eccentricity and changes in acceleration behavior. Manufacturing eccentricity and deviations in rotor magnetization are discussed as potential contributors to the observed effects. The findings emphasize static eccentricity as a critical parameter in NVH optimization, particularly in electrified powertrains. However, the results indicate that further investigations are needed to explore the influence of eccentricities and magnetization deviations on NVH behavior comprehensively.

In micromobility applications, maintaining satisfactory motor drive performance in the full torque-speed envelope of an outer rotor non-salient permanent magnet synchronous machine is a challenge due to the drastic performance degradation with the increasing non-linearity above the nominal ratings of the motor. In this article, we tackle this challenge via fuzzy gain scheduling proportional–integral speed controllers that have been designed by taking into account practical considerations. On the basis of experimental voltage ripple analyses conducted on the speed control loop with different system characteristics, we develop a single-input fuzzy gain scheduling proportional–integral speed controller and a double-input fuzzy gain scheduling proportional–integral speed controller to reduce the voltage ripples while providing satisfactory dynamical performance. The proposed structures continuously adjust the characteristics of the speed control loop within a specified region to exhibit different dynamical system characteristics against varying conditions. It is verified by the experimental test results that the proposed structures successfully reduced the increasing voltage ripples as the disturbances increase while providing satisfactory dynamical performance. Finally, we provided a discussion on the trade-off between the proposed structures and suggested deploying single-input fuzzy gain scheduling proportional–integral controller for micromobility speed control applications as it is agnostic to noise to a certain degree hence offering better reliability. [ABSTRACT FROM AUTHOR]

Direct-torque-control-driven permanent magnet synchronous machines eliminate the need for a position sensor while providing improved torque dynamics. However, the structure, regulation principle and nature of compensation of hysteresis-based controllers used in direct torque control impacts performance under faulty operating conditions. This paper analyzes the reaction of direct torque control to the presence of various faults that occur in permanent magnet synchronous machines. The analysis presented reveals that the direct torque control injects a negative sequence voltage and manipulates the torque angle to meet the control objectives when a fault occurs. The co-simulation of finite element analysis and a multi-physic circuit simulator is used to validate the response of the hysteresis-based controller to the machine health. The results indicate that the hysteresis comparators have the ability to mask the impact of the faults in the direct-torque-control-driven permanent magnet synchronous machines. [ABSTRACT FROM AUTHOR]

This article deals with the design of an active fault‐tolerant control (AFTC) for a twin wind turbine consisting of two wind turbines mounted on the same tower. When one of the turbines is impacted by electrical faults, precisely a stator inter‐turn short circuits fault or a demagnetization fault, the sparse recovery diagnosis method is used for the detection, isolation and estimation of the active fault. An AFTC law is designed for the supervision of the faulty machine. Both methods, concerning diagnosis and control, are based on homogeneous theory and consequently converge in finite time. Simulation results highlighting the relevance of the proposed approach are also presented. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents the efficiency improvement of a pole-changing vernier machine (PCVM) by considering the residual magnetic flux density ( B r ) of low coercivity force (LCF) permanent magnets (PMs). The PCVM operates in two modes: vernier machine (VM) mode and permanent magnet synchronous machine (PMSM) mode, achieved through pole-changing. Pole-changing involves reversing the magnetic flux direction of LCF PM to alter the number of rotor pole pairs. By changing the number of rotor pole pairs, the PCVM operates as a VM mode at low speeds, providing high torque, and as a PMSM mode at high speeds, offering high efficiency. To achieve this, a combination of high coercivity force (HCF) PM and LCF PM is utilized in a single structure. The magnetic flux direction in the LCF PM is determined by B r , and the highest efficiency is achieved when B r reaches its maximum value | B r m |. This paper focuses on improving efficiency by obtaining B r m in VM mode and − B r m in PMSM mode through the design process. Additionally, finite element analysis (FEA) is employed to compare the performance of the improved model, which considers B r , with that of the conventional model, designed without considering B r . The improved model achieves higher B r values in each mode compared to the conventional model, resulting in increased torque density. Consequently, this leads to improved efficiency. [ABSTRACT FROM AUTHOR]

This paper presents research on an unconventional electric machine. It is a hybrid excited machine which includes the features of three types of machines: the Permanent Magnet Synchronous Machine, the Synchronous Machine, and the Synchronous Reluctance Machine. Therefore, a broad literature review related to the above-mentioned types of machines was constructed. The well-known Permanent Magnet assisted Synchronous Reluctance Machine joins features of Permanent Magnet Synchronous Machine and Synchronous Reluctance Machine topologies. This paper shows the results of the innovative design of the Hybrid Excited Permanent Magnet assisted Synchronous Reluctance Machine, which additionally has advantages of the Synchronous Machine. In the article the basic methods of electromagnetic flux control and the designs using them are also presented. Finally, the results of simulation studies of the effect of the stator skew on the machine performance are described. [ABSTRACT FROM AUTHOR]

Taking the permanent magnet synchronous motor (PMSM) as the research object, the model prediction pulse pattern control (MP3C) of a PMSM running in the medium–low-speed zone is adopted to further reduce the torque ripple and phase current total harmonic distortion (THD) of a motor running in the medium–low-speed zone. First, the objective function of the predictive pulse control method is optimized. The objective function is intended to be the difference between the switching voltage vector and the equivalent reference voltage vector. At the same time, the integral of the difference between the d-axis current reference value and the actual value is compensated into the voltage reference vector. Thus, the pulse pattern control selected by the objective function is optimal when the motor is running in the medium–low-speed region. In addition, the PMSM can run stably and reliably. Simulation results show that the torque ripple is reduced by 1.3 Nm and 1.2 Nm, and that the phase current total harmonic distortion is reduced by 0.10% and 0.03% when the motor is running at 5 Nm and 10 Nm and at a speed of 100 rpm, respectively. When the rotation speed is 1000 rpm, the torque ripple is reduced by 0.74 Nm and 0.78 Nm respectively. In addition, the phase current total harmonic distortion is decreased by 0.44% and 0.54%, respectively. [ABSTRACT FROM AUTHOR]

With their simple structure, good characteristics, small size, low weight, high starting torque, and high power density, permanent magnet synchronous motors (PMSM) are widely used in industry and national projects. However, accurate PMSM d–q-axis inductance values cannot be obtained after dynamic decoupling of the d–q-axis voltages of a PMSM under vector control. To tackle this challenge, this paper proposes a two-line-same-phase AC standstill measurement (TLSP-ACSM) method. To verify the effectiveness of the proposed method, both the motor synthetic magnetomotive force and theoretical error of inductance measurement based on the TLSP-ACSM method are analyzed, followed by experiments to demonstrate the effectiveness of TLSP-ACSM. By comparing the proposed method with another measurement method, it is demonstrated that the relative error of the d-axis and q-axis inductance measurements is reduced by about 23% and 21%, respectively. When considering magnetic flux leakage, TLSP-ACSM shows better measurement precision and tracking performance. [ABSTRACT FROM AUTHOR]

Pulse–width modulated inverters are commonly used to control electrical drives, generating a common mode voltage and current with high–frequency components that excite the parasitic capacitances within electric machines, such as permanent magnet synchronous machines or induction machines. This results in different types of bearing currents that can shorten the service life of electric machines. One significant type of inverter–induced bearing currents are high–frequency circulating bearing currents. In this context, this work employs finite element analysis and time-domain simulations to determine the common mode current and circulating bearing current for various permanent magnet synchronous machine designs based on the traction machines of commercial electric vehicles with a focus on the stator. The results suggest that the ratio between the circulating bearing current and common mode current is much smaller in permanent magnet synchronous machines for traction applications than previously established in conventional induction machines, with values below 10% for all analyzed designs. A further increase in the robustness of such electric machines to the detrimental effects caused by the inverter supply could be achieved by reducing the parasitic winding–to–stator capacitance or by increasing the stator endwinding leakage inductance. [ABSTRACT FROM AUTHOR]

Copyright of Automatisierungstechnik is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The fault-tolerant control system (FTCS) for a permanent magnet synchronous motor (PMSM) is presented and an analysis of speed sensor faults is proposed in this paper. The detection and compensation of speed sensor faults is based on the simple comparison of the measured signals with the signals estimated by reduced-order sliding mode observer (SMO). The focus of the work is on the presentation of simulation and experimental research for the most common speed sensor failure types: complete signal loss, gain error, and measurement noise. Additionally, an analysis of different operating conditions of the PMSM drive system is presented, which highlights the system’s behaviour under various conditions. The presented algorithm enables the fast detection and compensation of failures with very short detection times, making it a versatile solution for a PMSM drive system and improving its overall reliability.

Optimization of rotating electrical machines is both time- and computationally expensive. Because of the different parametrization, design optimization is commonly executed separately for each machine technology. In this paper, we present the application of a variational auto-encoder (VAE) to optimize two different machine technologies simultaneously, namely an asynchronous machine and a permanent magnet synchronous machine. After training, we employ a deep neural network and a decoder as meta-models to predict global key performance indicators (KPIs) and generate associated new designs, respectively, through unified latent space in the optimization loop. Numerical results demonstrate concurrent parametric multi-objective technology optimization in the high-dimensional design space. The VAE-based approach is quantitatively compared to a classical deep learning-based direct approach for KPIs prediction.

This article investigates a bearingless motor with passive electrodynamic axial suspension. The axial suspension force is generated by a specific coil configuration called a figure-eight coil. Radial directions and tilting angles are stabilized by passive permanent magnet bearings. Since axial electrodynamic force increases with rotational speed, it must overcome a certain minimum threshold speed to compensate for the rotor weight and the unstable axial force caused by the permanent magnet bearing. Theoretical equations are derived for the braking torque caused by the suspension current and for the steady-state axial equilibrium position at constant rotational speed. A method based on the braking torque equation is proposed for correcting the mismatch between the magnetic center of the bearingless motor and the middle point of the axial clearance. This method sets the middle point between upper and lower touchdown positions in the same place where the motor current is minimum during passive axial suspension. Axial suspension is confirmed in the experiment with a noncontact laser sensor.

This paper proposes a three-phase dual-winding permanent magnet synchronous machine (PMSM) providing multitasked operation for accessory drive systems in hybrid electric vehicles (HEV). The novelty of this research lies in the machine having special slots and pole combinations with specific configuration of two sets of double-layer concentrated group winding separated by the unwound tooth between the phase groups formed on the same stator to achieve both the motoring and generator operation simultaneously as well as independently. These operations are accomplished by incorporating motor and generator winding separately on the same stator of a single PMSM machine. This single machine is particularly designed to eliminate the mutual coupling between these two sets of windings such that the load variation on the generator does not affect the mechanical output power of the motor. To confirm this multitasking, the electromagnetic design of the machine has been presented, and its operating modes are analyzed. The performance is compared using finite element analysis with that of a conventional PMSM machine having a double-layer winding configuration.

The paper presents an accurate analytical subdomain model for predicting the electromagnetic performance in the symmetrical dual three-phase surface-mounted permanent magnet synchronous machine (PMSM) under open-phase faulty conditions. The model derivations are extended from previous accurate subdomain models accounting for slotting effects. Compared with most conventional subdomain models for traditional three-phase machines with nonoverlapping winding arrangement, the subdomain model proposed in this paper applied for the 24-slot/4-pole dual three-phase machine with symmetrical overlapping winding arrangement. In order to investigate the postfault electromagnetic performance, the reconfigured phase currents and then current density distribution in stator slots under different open-circuit conditions are discussed. According to the developed model and postfault current density distribution, the steady-state electromagnetic performance, such as the electromagnetic torque and unbalanced magnetic force, under open-circuit faulty conditions are obtained. For validation purposes, finite element analysis (FEA) is employed to validate the analytical results. The result indicate that the postfault electromagnet performance can be accurately predicted by the proposed subdomain model, which is in good agreement with FEA results.

In this article remanence deviations of a permanent magnet synchronous machine are studied with the proper orthogonal decomposition (POD). The design of experiments enables to create designs with a reduced sample size compared to full factorial designs without decreasing the stochastic significance of the remanence distributions. Next, a POD basis is created with the belonging design, that is distinctly smaller than the reference. From the POD basis the projection matrix is built to compute the flux density solutions. The machine's output is then analyzed regarding accuracy originating from numerical errors. Different parameters are evaluated and compared to the reference to appraise the accuracy of the flux density solutions, which includes the POD basis size, rotor angle step size and dimension of the reduced system. Results show, that the most influence has the dimension of the reduced system. Depending on the dimension and other parameters about one quarter of computational effort can be conserved without a significant loss in accuracy. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to define and analyze the steps that should be followed in order to design an electric machine, a Permanent Magnet Synchronous Machine (PMSM) in this case. First of all, the specifications of the machine to be designed must be clearly defined. The next step would be, of course, choosing the materials from which the main components of the machine are made, as well as determining the optimal combination of pols-slots, so that the machine is as efficient as possible. Then, the machine winding configuration must be chosen, this step being a very important one, considering that it has a great influence on the machine's performances. The next step would be to carry out a complete analysis of the machine, both from an electromagnetic, structural, and thermal point of view, using one of the software packages available on the market. [ABSTRACT FROM AUTHOR]