Interior Permanent Magnet Synchronous Motor Research Articles

Optimization of cogging torque in interior permanent magnet synchronous motor using optimum magnet v-angle

Introduction. At present, the most important requirement in the field of electrical engineering is the better utilization of electrical power, due to its increasing demand and not-so-increasing availability. A permanent magnet synchronous motor (PMSM) is increasingly gaining popularity in various household and industrial applications because of its superior performance compared to conventional electrical motors. Purpose. PMSM is designed based on the selection of various design variables and optimized to fulfill the same. Being superiorly advantageous over other motors, PMSM has the major disadvantage of higher cogging torque. Higher cogging torque generates torque ripple in the PMSM motor leading to various problems like vibration, rotor stress, and noisy operation during starting and steady state. The designer should aim to reduce the cogging torque at the design stage itself for overall better performance. Methods. An interior rotor v-shaped web-type PMSM is designed and its performance analysis is carried out using finite element analysis (FEA). Magnet v-angle is optimized with the objective of cogging torque reduction. Performance comparison is carried out between the optimized motor and the initially designed motor with FEA. Novelty. Magnet v-angle analysis is performed on the same keeping all other parameters constant, to obtain minimum cogging torque. The proposed method is practically viable as it does not incur extra costs and manufacturing complexity. Practical value. It is observed that the magnet v-angle is an effective technique in the reduction of cogging torque. Cogging torque is reduced from 0.554 N×m to 0.452 N×m with the application of the magnet v-angle optimization technique.

Investigation of the impact of rotor shaping on the torque and radial force harmonics of a V‐shape interior permanent magnet synchronous machine

AbstractThis paper introduces a technique aimed at improving the performance of an interior permanent magnet synchronous machine (IPMSM) by reducing torque ripple and radial force harmonics. Unlike conventional IPMSMs, the proposed method employs a variable airgap length that is defined by a mathematical function. Two distinct rotor shapes are investigated to determine the most efficient design. Finite Element Analysis is employed to assess both the electromagnetic and mechanical attributes of the proposed motors. It compares the results for three operating points of the shaped motor with those of a conventional one. The investigation delves into the influence of rotor geometry on key output parameters, including Back Electromotive Force (back‐EMF) harmonics, average torque, cogging torque, torque ripple, efficiency, power factor, and radial force harmonics. The findings indicate that optimising rotor shape can significantly enhance IPMSM performance by reducing torque ripples and radial force harmonics, while simultaneously increasing average torque and efficiency at different operating points.

Performance analysis of a permanent magnet synchronous motor with dual stator windings

This paper presents the modelling and performance analysis of a line-start three-phase interior permanent magnet synchronous motor (IPMSM) with dual stator windings. The machine has two sets of windings, main and auxiliary windings. The main winding is connected to the supply while the auxiliary is connected to a balanced capacitor. The dynamic model equations are derived in the d-q rotor reference frame using the concept of winding function theory. The machine input impedance was construed from the steady-state equations, where the effects of capacitance on the performance of the motor were studied. An improved torque was obtained when a suitable capacitance was connected to the auxiliary winding. A point of good performance was established by enhancing its direct axis reactance and the quadrature axis reactance which depend on the size of the capacitor. It is shown that thenew configuration has better performance characteristics when compared with those of the traditional configuration in terms of output power, torque density and efficiency.

Optimal Design Method of Post-Assembly Magnetizing Device with Field–Circuit Coupling Analysis

Post-assembly magnetization can significantly simplify the manufacturing of the rotor of permanent magnet (PM) electrical machines. The optimization of the post-assembly magnetizing device using finite element analysis (FEA) is time-consuming; therefore, a globally optimal solution aiming at achieving an adequate magnetizing level and minimal energy consumption is difficult to achieve. In this paper, a field–circuit coupling analysis (FCCA) model is proposed to optimize the auxiliary stator-type magnetizing device for interior permanent magnet synchronous machines (IPMSMs). A reasonable simplification of the highly saturated magnetic circuit is made based on FEA results so that the magnetic equivalent circuit (MEC) model can be established. On the other hand, the eddy currents in the PMs are equivalent to an eddy current short-circuit; thus, by converting the field calculation into a circuit calculation, the time cost can be reduced significantly, which greatly improves the speed of multi-objective optimization of the magnetizing device with multiple degrees of freedom. A V-type IPMSM is taken as a study case, and its post-assembly magnetizing device is optimized with the proposed method. FEA and experimental results show that the PMs are fully magnetized, while the required energy consumption is greatly reduced when compared with an existing magnetizing device.

Accuracy improvement of maximum torque per ampere control for interior permanent magnet synchronous motor drives reflecting PM flux linkage variations

Accuracy improvement of maximum torque per ampere control for interior permanent magnet synchronous motor drives reflecting PM flux linkage variations

Position Sensorless Control of Dual Three-Phase IPMSM Drives With High-Frequency Square-Wave Voltage Injection

Dual three-phase interior permanent-magnet synchronous motor (IPMSM) drives have received more attention by the merits of better fault-tolerant capability and lower torque ripples. To improve the reliability of the system against failures in position sensor, it is necessary to investigate the position estimation method for dual three-phase IPMSM drives. The high-frequency (HF) signals injection is utilized for position estimation in three-phase IPMSM drives during low-speed operation region. However, the torque ripples are inevitable owing to the mixing of fundamental and HF components in the same control space for three-phase IPMSM drives. In this paper, the position sensorless control method has been proposed by injecting HF square-wave voltage in the harmonic subspace for the dual three-phase IPMSM drives. Since the harmonic subspace is decoupled from the torque subspace, the torque disturbance can be mitigated well with the proposed HF signal injection based position sensorless method. Moreover, the digital filters in signal extraction and current feedback can be avoided and the signal separation process becomes easy with the proposed method. The experiments have been conducted to validate the performance of the proposed method.

Finite Set Sensorless Control With Minimum a Priori Knowledge and Tuning Effort for Interior Permanent-Magnet Synchronous Motors

Finite Set Sensorless Control With Minimum a Priori Knowledge and Tuning Effort for Interior Permanent-Magnet Synchronous Motors

Analysis and optimization of interior permanent magnet synchronous motor for electric vehicle applications using ANSYS Motor-CAD

The Permanent Magnet Synchronous Motor (PMSM) has the capability to high torque to current ratio, high power to weight ratio, high efficiency and stability. Due to the above positive points, PMSM is extensively employed in recent variable speed AC drives, particularly in electric vehicle applications. The electric vehicle is convenient for the city traffic without toxic gas emissions with low noise. PMSM became at the top of AC motor types due to the positive features written in the previous lines. However, it has two major drawbacks i.e. high cost and small speed range but it can be controlled and exceed to the small speed range with some control methods. A radial flux inner rotor PMSM architecture for electric vehicle application is presented in the project. The Interior Permanent Magnet Synchronous Motor (IPMSM) of the electric vehicle Leaf model, which was first produced by Nissan company in 2012, will be analyzed with ANSYS Motor-CAD and then the analysis results will be compared with the theoretical results and finally will be optimized in the project. The paper will provide insights about various change of parameters and their effects to the other parameters.

Performance Analysis of Conventional IPMSM and NCPM Based IPMSM

This paper proposes a NCPM (Nano-composite coated permanent magnets)-based IPMSM (Interior Permanent Magnet Synchronous Motor) electric drive system, especially applicable for electric vehicles (EV). For an EV, an increase in the “T/A (torque per ampere)” condition is highly recommended, as it directly affects the maximum distance run by EV on a single charge. Due to NCPM, a substantial increase in magnetic flux intensity, resistance to corrosion and Curie temperature are observed. As a result, the proposed drive clearly exhibits a higher power to weight ratio. Also, it is capable of delivering higher T/A to the drive system without any considerable change in two important factors of EV: (1) mass and volume of the drive system (2) battery capacity of the drive system. Moreover, NCPM performance is less susceptible to temperature variation, which makes it an appropriate candidate for vehicular applications, where temperature inconsistency could be a common issue during working conditions. Also, NCPM-based IPMSM offers a quicker speed response than conventional IPMSM, thus providing higher acceleration, which is one of the important performance factors for vehicular applications. A vector controlled mathematical model of IPMSM and NCPM-based IPMSM is tested for various speed commands. Also, the NCPM-based IPMSM, in the proposed configuration, is fed from a three-level DCMLI (diode clamped multi-level inverter), as the drive system is considered for medium to high power applications. A comparative performance analysis is carried out between the proposed drive system and a conventional IPMSM-based drive system using MATLAB/SIMULINK to indicate the efficacy of the proposed configuration.

Optimized FCS-MPCC based on disturbance feedback rejection for IPMSMs under demagnetization fault in high-speed trains

This paper proposes an optimized finite control set model predictive current control (FCS-MPCC) strategy based on disturbance feedback rejection control (DFRC) method for interior permanent magnet synchronous motors (IPMSM) employed in high-speed trains. The strategy aims to mitigate the impact of parameter mismatch caused by permanent magnet demagnetization faults. Firstly, a discrete predicting model is established for IPMSMs, considering the mismatch in flux linkage, resistance, and inductance. The analysis is conducted to evaluate the impact of disturbances caused by demagnetization faults on the traditional FCS-MPCC. Secondly, second-order sliding mode disturbances observers (SMDOs) are utilized to detect real-time disturbances under demagnetization faults. The stability analysis of the second-order SMDOs is conducted using a Lyapunov function. Furthermore, disturbance controllers are developed to regulate the disturbances and generate compensating values for the FCS-MPCC. Lastly, experimental validation is performed on two IPMSMs to demonstrate the effectiveness of the proposed DFRC-based FCS-MPCC strategy against parameter mismatch issues caused by demagnetization faults.

Analysis of Vibration and Noise in a Permanent Magnet Synchronous Motor Based on Temperature-Dependent Characteristics of Permanent Magnet

Interior permanent magnet synchronous motors (IPMSMs) are widely utilized due to their high power density. However, noise and vibration issues are often encountered in these motors. While researchers have extensively investigated individual aspects such as noise, vibration, and heat generation in PMSMs, there has been a lack of comprehensive studies examining the interrelationships among these factors. In this paper, a novel approach is proposed for predicting vibration by considering the radial force in the air gap as the exciting force, while also accounting for the changes in the permanent magnet (PM) characteristics caused by heat generation during motor operation. The method involves decomposing and identifying vibration components associated with each vibration mode and predicting noise based on the sound radiation efficiency of each mode. By constructing a vibration map based on current and temperature at a specific frequency, the components most affected by current variations and PM characteristics can be identified. This allows for the proposal of design improvements aimed at reducing vibration. Furthermore, by comparing the vibration map with the noise map, it is confirmed that vibration serves as a source of noise and influences its generation. However, it is found that vibration and noise are not strictly proportional. Overall, a comprehensive analysis of the correlations between vibration, noise, and other factors in IPMSMs is presented in this study. The proposed method and findings contribute to the understanding of the complex dynamics involved and provide valuable insights for the design of quieter and more efficient motor systems.

System-Level Simulation of 120 kW Interior Permanent Magnet Synchronous Motor Drive for Electric Vehicle Usage Under Various Types of Faults for Fault Diagnosis

Owing to the recent trend toward the zero-carbon emission, drive motors are gaining attention for substitute for internal combustion engine. Among them, interior permanent magnet synchronous motor(IPMSM) is being extensively used for their high-power density. Consequently, verification of safety and reliability for IPMSM is becoming an important subject. In this study, system-level simulation for IPMSM drive system under various failure modes were carried out. Fault characteristics were extracted from the phase current profile and classified by the support vector machine. It is shown that with the proposed model, faults can be detected with less cost and time-consumption.

Enhanced Linear ADRC Strategy for Sensorless Control of IPMSM Considering Cross-Coupling Factors

Estimation of rotor coordinate system by high-frequency (HF) signal injection is an effective sensorless control strategy, which can solve the decoupling problem of position information of interior permanent magnet synchronous motor (IPMSM) in the low-speed range. However, the inductance cross-coupling phenomenon caused by magnetic saturation will lead to a decline in the accuracy of rotor angle extraction, resulting in a serious deterioration of the sensorless control performance. To solve this problem, an HF signal injection method considering <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d-q</i> axis coupling inductance is proposed to estimate HF inductance and the rotor angle. The estimated HF inductor combined with the current loop enhanced linear active disturbance rejection control (ELADRC) is used in the current loop control to estimate the disturbance and improve the current regulation quality of the current control system. Furthermore, the stability and the tracking performance of the enhanced LADRC are analyzed theoretically. Finally, the stability of a closed-loop IPMSM drives system based on ELADRC considering HF inductance is analyzed. The experimental results of a salient pole IPMSMs driver verify the effectiveness and practicability of the scheme.

Fast Magnetic Field Prediction Based on Hybrid Subdomain Method and Multiobjective Optimization Design for Interior Permanent Magnet Synchronous Machines

Benefiting from the prosperity of new energy industry, interior permanent magnet synchronous machines (IPMSM) have ushered in unprecedented development opportunities. To further suppress defects and enhance engineering practicality, fast magnetic field prediction based on hybrid subdomain method and multiobjective optimization design for IPMSM are studied. First, fast no-load magnetic field prediction model based on hybrid subdomain method for IPMSM is innovatively proposed. By combining master/slave subdomain division method and lumped parameter magnetic equivalent circuit, complex rotor structure and saturation effects of magnetic bridges and cores can be comprehensively considered. Prediction model has extremely high calculation accuracy and speed. After that, based on the proposed prediction model, a multiobjective optimization model combining Taguchi method and nondominated sorting genetic algorithm II (NSGA-II) is implemented. Model optimization efficiency has been greatly improved scientifically and effectively. Finally, the efficiency, advancement, innovation, and engineering practicability of studied prediction and optimization models are well verified through a series of finite element analysis (FEA) and prototype experiments. In addition, the generality and universality of this study are verified for other types of IPMSM.

Reduction of Torque Vibration in Integrated On-board Chargers Using Stator Windings of an IPMSM

This study proposed a control method to reduce the torque ripple vibration of an integrated on-board charger using the windings of an interior permanent magnet synchronous motor (IPMSM). During a battery-charging operation, stopping the motor results in noise, as well as damage to the motor and other components from the torque vibration caused by the charging current. In the proposed control method, the generated torque was estimated using a back-electromotive force table, and the phase current was controlled to eliminate the torque. The proposed method can suppress torque vibration, irrespective of the angle of the rotor in the IPMSM. The effectiveness of the proposed method was verified experimentally, with the torque vibration suppressed by 94% compared with that of the conventional control method.

Simultaneous Identification of Inverter and Machine Nonlinearities for Self-Commissioning of Electrical Synchronous Machine Drives

The proposed identification method allows for a simultaneous estimation of nonlinear output voltage deviations in voltage source inverters (VSIs) and nonlinear synchronous machine models. Based on the identified characteristics with the help of physically inspired structured artificial neural networks (ANNs), an efficient tuning of the current control system can be performed and the nonlinear voltage deviations caused by parasitic effects and dead-time distortions can be accurately compensated for. The identification is performed without position sensor while the rotor is mechanically locked by utilising measured phase currents and reference machine voltages only. Experiments for an interior permanent magnet synchronous machine (IPMSM) and a reluctance synchronous machine (RSM) show that the proposed method is capable of identifying the current dependent self-axis and cross-axis flux linkages, differential inductances and the nonlinear VSI voltage deviations as well as the phase resistance at the same time. The proposed method is fast and generic. Besides the rated machine current, voltage and frequency, no prior system knowledge is required making it applicable for the self-commissioning of any electrical synchronous machine drive.

Sensorless vector control approach for the interior PM synchronous machine with DC-offset compensation loop

Two different DC offset compensators for sensorless PMSM, motor drives with wide speed range flux linkage observers, are introduced and compared. The first one is an improved flux observer with PI correction and no need for mover speed and phase adaptation. The second one is a novel flux observer with an active disturbance rejection controller (ADRC) compensator without mover speed adaptation. The ESO built into ADRC is able to detect and compensate for both internal model disturbance and external load disturbance, resulting in a controller with superior dynamic responsiveness and robust regulation. In both scenarios, an injected direct current (DC) offset is calculated and maintained by the PI integral part and ADRC, which effectively compensates for the DC biases and drifts caused by the sampling channels. Compared to the PI controller, ADRC demonstrates greater transient performance and disturbance robustness. The results of theoretical analysis and Matlab simulations have confirmed the feasibility and efficiency of the proposed strategy.

A Dual-Level Adaptive Law Design for Super-Twisting Algorithm in Sensorless IPMSM Drives

This paper proposes a dual-level adaptive law for third order super-twisting extended state observer (STESO) in a hybrid sensorless IPMSM drive. According to Lyapunov stability analysis, the coefficients of a super-twisting sliding-mode observer are often constrained by a lower limit to ensure robustness. However, when working in the wide-speed region, this constraint is too ambiguous to serve as a practical tuning guideline. A dual-level adaptive STESO is proposed using equivalent control and Lyapunov stability analysis to extend the operating range while simultaneously suppressing sliding-mode ripples. A rigorous stability analysis is presented, and a tuning guideline for guaranteeing the convergence of the whole algorithm is included. Besides, at low speeds, improvements have been made in torque ripple suppression and cross-coupling effect compensation, and their effectiveness has been validated both theoretically and practically. Several effective experimental results are presented to verify the feasibility of the proposed observer on the interior PMSM drive platform.

Modified Super-Twisting Algorithm-Based Model Reference Adaptive Observer for Sensorless Control of the Interior Permanent-Magnet Synchronous Motor in Electric Vehicles

In this paper, the model reference adaptive system (MRAS) method has been employed to observe speed in sensorless field-oriented control (FOC) with flux weakening (FW) and maximum torque per ampere (MTPA) operations for the interior permanent-magnet synchronous motor (IPMSM). This paper focuses on the modified MRAS observer, which is based on the sigmoid function as a switching function and also the adaptive sliding mode coefficient. The sliding mode strategies are employed for the adaptation mechanism instead of the PI controller. The conventional PI-MRAS causes oscillations in rotor speed. To solve this problem, the modified adaptive super-twisting algorithm (STA)-based MRAS method is proposed by utilizing the sigmoid function. The proposed modified MRAS is compared to conventional methods. Additionally, it is examined for performance against the fast terminal sliding mode (FTSM), which is applied to the MRAS as an adaptation mechanism in terms of sliding mode strategies. The modified STA-MRAS is explored under the ECE and EUDC (Extra Urban Driving Cycle) drive cycles for electric vehicle applications. Finally, the obtained results show the validity and capability of the proposed adaptive STA-MRAS in terms of speed tracking.

Multiparameter Estimation-Based Sensorless Adaptive Direct Voltage MTPA Control for IPMSM Using Fuzzy Logic MRAS

This paper introduces a parameter-estimation-based sensorless adaptive direct voltage maximum torque per ampere (MTPA) control strategy for interior permanent magnet synchronous machines (IPMSMs). In direct voltage control, the motor’s electrical parameters, speed, and rotor position are of great significance. Thus, any mismatch in these parameters or failure to acquire accurate speed or position information leads to a significant deviation in the MTPA trajectory, causing high current consumption and hence affecting the performance of the entire control system. In view of this problem, a fuzzy logic control-based cascaded model reference adaptive system (FLC-MRAS) is introduced to mitigate the effect of parameter variation on the tracking of the MTPA trajectory and to provide precise information about the rotor speed and position. The cascaded scheme consists of two parallel FLC-MRAS for speed and multiparameter estimation. The first MRAS is utilized to estimate motor speed and rotor position to achieve robust sensorless control. However, the speed estimator is highly dependent on time-varying motor parameters. Therefore, the second MRAS is designed to identify the quadratic inductance and permanent magnet flux and continuously update both the speed estimator and control scheme with the identified values to ensure accurate speed estimation and real-time MTPA trajectory tracking. Unlike conventional MRAS, which uses linear proportional-integral controllers (PI-MRAS), an FLC is adopted to replace the PI controllers, ensuring high estimation accuracy and enhancing the robustness of the control system against sudden changes in working conditions. The effectiveness of the proposed scheme is evaluated under different speed and torque conditions. Furthermore, a comparison against the conventional PI-MRAS is extensively investigated to highlight the superiority of the proposed scheme. The evaluation results and our quantitative assessment show the ability of the designed strategy to achieve high estimation accuracy, less oscillation, and a faster convergence rate under different working conditions. The quantitative assessment reveals that the FLC-MRAS can improve the estimation accuracy of speed, permanent magnet flux, and quadratic inductance by 19%, 55.8% and 44.55%, respectively.