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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. [ABSTRACT FROM AUTHOR]

An interior permanent magnet synchronous motor (IPMSM) with "VV—" shape rotor topology structure is proposed, and its performances are compared with "V" shape and "V—" shape rotor topology structure. The results show that the performances including output average torque, reluctance torque, torque ripple, cogging torque, iron loss of the IPMSM with "VV—" shape is better than the other two rotors. Firstly, the parameters which have great influence on the torque and the efficiency of the IPMSM are analyzed and optimized. The no‐load back electromotive force (EMF) of three different optimized rotor topology structures are analyzed and compared, the results show that the no‐load back EMF of the IPMSM with "VV—" shape topology structure has the lowest total harmonic distortion rate (THD). Secondly, the torque of the IPMSM with "VV—" shape under different current angles, current densities and speeds are analyzed and compared with the other two rotors. The results show that the torque performance of the IPMSM with "VV—" shape rotor topology structure is better than that of the other two. Finally, aiming at the problems that the torque ripple and cogging torque of the IPMSM with "VV—" shape rotor topology structure are greatly increased when the iron loss is reduced, This paper proposes to add a set of circular flux isolation holes between the second layer and the third layer of permanent magnets, and the position and diameter of this set of circular flux isolation holes are optimized and adjusted. The results show that the torque ripple and cogging torque of the IPMSM with the further optimized "VV—" shape rotor topology structure are greatly reduced, and the THD of no‐load back EMF is also further reduced, which has great significance to reduce vibration and noise, improve the control accuracy of the IPMSM. [ABSTRACT FROM AUTHOR]

Although it is crucial to design the magnetic flux path and the maximum torque per ampere (MTPA) current reference under the current limitation, it is challenging to simultaneously consider these features in developing an interior permanent magnet synchronous motors (IPMSM) due to complicated coupling effects. In this article, to overcome the above issue, the motor-design parameters are estimated by conducting electromagnetic finite element (FE) analysis two times at every iteration of topology optimization. Then, the MTPA current phase angle can be analytically expressed in terms of an elementwise relative density (i.e., design variable in topology optimization). In addition, the structural safety is assessed by conducting the structural FE analysis under design-dependent loads to reflect a high-speed rotation. The proposed two-stage topology optimization enables us to simultaneously optimize both a structural design and current phase angle to achieve the maximum electromagnetic performance. Structural safety and manufacturability are also considered to obtain a practically meaningful design. With two different types of permanent magnets, the optimized IPMSMs are obtained and manufactured to validate the proposed method. Simulation and experimental results demonstrate the validity and potential of this work. [ABSTRACT FROM AUTHOR]

An interior permanent magnet synchronous motor (IPMSM) with 'VV—' shape rotor topology structure is proposed. The established two‐dimensional (2D) parameterized finite element analysis (FEA) models are used to analyze and compare the output average torque, torque density, air‐gap flux density and back electromotive force (EMF) of the IPMSM with 'V' shape, 'V—' shape, 'VV—' shape for electric vehicle (EV) applications. The rotor topology structure has a great influence on the performance of the IPMSM, especially the first layer of permanent magnet of the multi‐layers permanent magnet structure has the greatest influence on the performance of the IPMSM. Therefore, firstly, this paper mainly analyzes and optimizes the opening angle of permanent magnet and the pole arc angle of the first layer, which have a great influence on the electromagnetic performance of the IPMSM. Secondly, the d‐axis and q‐axis inductance, saliency ratio, output average torque, reluctance torque under different current angles are analyzed and compared. The results show that the output average torque and reluctance torque of the IPMSM for EV applications with 'VV—' shape rotor topology structure proposed in this paper are larger than that of the other two rotor topology structures as the amount of permanent magnet with 'VV—' shape rotor topology structure is slightly reduced. Finally, the torque density versus current density of the IPMSM with three different rotor topology structures is analyzed and compared. The results show that the torque density of the IPMSM with 'VV—' shape proposed in this paper is higher than that of the other two rotor topology structures under different current densities. [ABSTRACT FROM AUTHOR]

In order to solve the problem that the three-phase current of the interior permanent magnet synchronous motor (IPMSM) contains the 11th and 13th current harmonics, a multiple synchronous rotating frame transformation (MSRFT)-based current harmonic suppression method is established. Firstly, the influencing factors of current harmonics in IPMSM vector control are analyzed, and the influence mechanism of the inverter's dead-time effect and the permanent magnet flux linkage harmonics on the current harmonics is described. Secondly, a simple current harmonic extraction method is proposed by optimizing the traditional current harmonic extraction method based on MSRFTs. The proposed method achieves the accurate extraction of the current harmonic components. Thirdly, a harmonic voltage generation method is established and is combined with the proposed current harmonic extraction method to form a current harmonic suppression strategy. Finally, the feasibility and effectiveness of the proposed method are verified via MATLAB/Simulink simulations and experiments. The simulation and experimental results show that the proposed current harmonic extraction method can extract the current harmonic components accurately, and the proposed current harmonic suppression strategy can suppress the 11th and 13th current harmonics effectively. [ABSTRACT FROM AUTHOR]

There is a certain amount of current harmonics in interior permanent magnet synchronous motor. In order to accurately control the current harmonic, this article focuses on three aspects: establishing current harmonic calculation model, extracting current harmonic, and designing current harmonic regulator. A current harmonic calculation model, which considers the effect of voltage harmonics induced by current controllers and digital control delay on the initial phase angle of voltage harmonics, is established for the first time. With the help of multiple synchronous rotating frame transformation, a current harmonic extraction method more suitable for motor drive field, which aims to extract the current harmonic characteristics of d-axis and q-axis currents, is proposed. On this basis, the controlled quantity and control quantity are unified in d–q coordinate frame for analyzing the coupling relationship of current harmonic characteristics. And then a PI current harmonic regulator, including current harmonic decoupling and voltage harmonic initial phase angle compensation, is constructed, so as to realize the effective control of current harmonics. Finally, the effectiveness and superiority of the proposed method are verified by simulation and experiments. [ABSTRACT FROM AUTHOR]

Due to the local inhomogeneous magnetic saturation of the core of the interior permanent magnet synchronous motor (IPMSM), the magnetic field changes nonlinearly, which makes the analytical calculation of the magnetic field difficult. Therefore, the calculation of the magnetic field mostly relies on the finite element method (FEM). However, the high computation cost of FEM restricts the efficiency of the design and analysis of IPMSM. In this article, an analytical model (AM) of slotless open-circuit air-gap magnetic field (OC-AG-MF) of IPMSM with V-shaped segmented skewed poles is derived by combining the subdomain method (SDM) and the magnetic equivalent circuit (MEC) method, and then, the AM of slotted OC-AG-MF of IPMSM with V-shaped segmented skewed poles is obtained by introducing the complex relative permeance. To show the effectiveness of the novel AM, the OC-AG-MF and cogging torque of an IPMSM with V-shaped segmented skewed poles for electric vehicles are calculated by the AM and FEM, respectively. The spatial order, amplitude–frequency characteristics, and the 3-D spatial distribution of the OC-AG-MF are analyzed. Finally, the accuracy of the AM is experimentally verified by direct measurement of OC-AG-MF and no-load back electromotive force (EMF) of the motor. The AM proposed in this article is shown to accurately calculate the radial and tangential components of OC-AG-MF of IPMSM with V-shaped segmented skewed poles considering rotor magnetic bridge saturation effect and stator slotting effect. Meanwhile, the efficiency of the design and analysis of the motor is expected to be improved due to the reduced computational effort compared to the prevalent FEM. [ABSTRACT FROM AUTHOR]

Moving from internal combustion engine based towards electric based transportation is crucial for wide societies as they facilitate the use of green energy technologies such as wind and solar. Interior mounted permanent magnet (IPM) machines, also known as salient brushless alternating current (AC) machines, are commonly employed in traction applications as they have superior features, such as high efficiency operation, high torque, and power densities. The efficiency optimization in IPM drives is achieved by obtaining and operating at accurate and unique current angle for a certain electromagnetic torque demand. In conventional drives, the optimum current angle is obtained by online utilization of iterative techniques. However, these techniques result in increased burden on the processor. In addition, accuracy of the generated current commands, and hence, the drive efficiency may significantly reduce if the number of iterations is not adequate. More importantly, online zero divisions issue may result in instability of the drive system at certain operating points in real life experiments. This paper proposes an efficiency optimized IPM drive with smooth output torque production addressing the aforementioned issues. The optimum operating points as a function of electromagnetic torque demand are computed offline by Newton–Raphson approximation technique in the paper, and they are stored in the controller as look-up tables, which are then employed to achieve optimum efficiency operation at a wide range. The superiority of the proposed drive is validated through extensive simulation of a 4.1 kW prototype IPM machine designed and manufactured for traction applications and the results are discussed in detail. The paper also presents detailed high efficiency control analysis of permanent magnet machines and hence it would be quite insightful for new researchers on the topic. [ABSTRACT FROM AUTHOR]

Summary: In this paper, an interior permanent magnet synchronous motor with a D‐type rotor configuration is presented. The performance of the proposed motor is compared with that of the widely used V‐type interior permanent magnet synchronous motor. For a fair comparison, all the motor parameters are identical. With the advent of different rotor topologies, multilayered and multisegmented permanent magnets are extensively used; however, an analytical modeling of D‐type interior permanent magnet synchronous motor has not yet been conducted. Furthermore, its analysis using the finite element method is considerably time‐consuming. To resolve this problem, an analytical method based on a magnetic equivalent circuit is proposed for the slotless D‐type interior permanent magnet synchronous motor. It is then compared with the finite element method at different pole arc–pole pitch ratios to demonstrate the effectiveness of the proposed method. Additionally, Schwarz‐Christoffel mapping is employed to maintain the slot shape and include the effect of adjacent slots by considering the slotting effect in the slotless air‐gap flux density. Finally, the presented motors are optimized based on the pole arc–pole pitch ratio to maximize the fundamental air‐gap flux density and minimize the total harmonic distortion. [ABSTRACT FROM AUTHOR]

The interior permanent magnet synchronous motor uses a barrier structure to block the magnetic flux circulating inside the rotor and to send the magnetic flux into the air gap. Although the airgap magnetic flux density can be increased through the barrier, there is the disadvantage of increased torque ripple. Thus, this study is conducted to determine whether the torque ripple could be reduced by changing the barrier shape. The problem here is that the torque inevitably decreases when the torque ripple is decreased. Therefore, in this study, a novel shape of the bridge is proposed in a model in which the torque ripple is reduced but the torque is not. The notch structure is applied to the bridge and is analyzed through finite-element method analysis. To intuitively express the relationship between the torque and the torque ripple, a torque efficiency factor is devised, and as a result, the torque is maintained but the torque ripple is reduced. [ABSTRACT FROM AUTHOR]

This article proposes a continuum-sensitivity-based method to obtain the optimal design for an interior permanent magnet synchronous motor (IPMSM). Compared with the finite difference method, the continuum sensitivity analysis shortens the computation time significantly when there are numerous design variables. We combine the continuum sensitivity with the shape constraint so that both the shape and the size can be optimized simultaneously and within a short time. This proposed design optimization method is applied to IPMSM rotor design, and its feasibility is verified. The proposed method is expected to be effective for various design problems that require the shape and the size to be optimized simultaneously. [ABSTRACT FROM AUTHOR]

A nonlinear observer for a class of nonlinear interconnected systems is introduced. The proposed methodology facilitates the observer design for nonlinear systems. Sufficient conditions criteria are derived to ensure asymptotical convergence of the proposed observer. The convergence of the proposed observer is studied in both nominal and abnormal cases. The designed observer is applied for self-sensing control of interior permanent magnet synchronous machine (IPMSM) to estimate the rotor position, the rotor speed, the stator resistance, and the load torque. Performance of the proposed observer algorithm is evaluated through real-time experiments using an industrial benchmark. Two cases are employed to prove the performance capability of the proposed self-sensing control algorithm. The first case measures the performance under normal operating condition. The influence of parameter deviations on the proposed self-sensing control algorithm is discussed to prove the robustness of the proposed observer in the second case. The accuracy of the proposed self-sensing control algorithm is greater than 93 %. [ABSTRACT FROM AUTHOR]

This paper mainly studies the influences of air-gap deformations on the electromagnetic performances and radial vibration characteristics of an interior permanent magnet synchronous motor (IPMSM) at peak rotating speed with rated power. Considering different air-gap states in the electromagnetic finite-element models of investigated IPMSMs, the effects of stator oval deformation, rotor centrifugal distortion, and both deformations on the air-gap magnetic flux field, radial and tangential magnetic force, and electromagnetic torque are analyzed and compared. Then, based on the accurate structural model of the stator system, the motor vibration characteristics are investigated with loading different electromagnetic force excitations on the stator inner face. Finally, the vibration experiments of the investigated IPMSM prototype are carried out to verify the results obtained by the simulations at a high-speed load condition. It is found that the air-gap deformations give a large increase in the particular vibration level. In order to improve the prediction accuracy of motor vibration characteristics, the air-gap deformations under all electromagnetic excitations, including magnetic force and torque pulsation, should be taken into consideration. [ABSTRACT FROM AUTHOR]

This paper examines how changing the magnetic orientation of permanent magnets in concentrated winding interior permanent magnet synchronous motors (IPMSMs) affects their demagnetization resistance. We evaluated a prototype for demagnetization at 180 °C that consists of a 130° V-shaped rotor core in which parallelogram magnets with oblique orientation are arranged and confirmed by finite element analysis where the demagnetization resistance increases as magnetic field orientation angle $\alpha $ becomes larger. For demagnetization evaluation of the prototype, it is easier to change the rotor core shape of a two-pole test rotor of a multipole IPMSM than a multipole rotor, and the demagnetization evaluation is performed using a small number of magnets. [ABSTRACT FROM AUTHOR]

This paper deals with the optimization design process of an interior-type permanent magnet synchronous motor (IPMSM) for electric compressors of air conditioners applied to electric cars and hybrid vehicles. Based on a prototype IPMSM, we identified the current level for efficiency and cogging torque using finite-element analysis (FEA). The IPMSM’s main design variables are optimized to primarily satisfy the target of efficiency and cogging torque. A second optimization design is carried out using the response surface method (RSM) for the main design variables obtained from the Taguchi method analysis. As a result, the optimization design is carried out through a two-step optimization design process using the Taguchi method and RSM. The IPMSMs are analyzed using FEA, and their validity is confirmed by comparing the test results against each step-by-step model. We validate an effective optimization design process using a two-stage design process. We conclude that the proposed approach provides an effective design method for engineers. [ABSTRACT FROM AUTHOR]

In this paper, a new mathematical modeling for a six-phase interior permanent magnet synchronous motor (IPMSM) is presented. The proposed model utilizes two synchronous reference frames. First, the flux model in the $abcxyz$ frame is mapped into the stationary $dq$ frames and then to two synchronous rotating frames. Then, differentiating the flux models, voltage equations are derived in rotating frames. Through this analysis, the interaction between the $abc$ and $xyz$ subsystems is properly described by a coupling matrix. The torque equation is also derived using the two reference current variables. Flux model was verified through FEM analysis. Experiments were done using a 100 kW six-phase IPMSM in a dynamo system. The validity of the torque equation was checked with some experimental results under a shorted condition on an $xyz$ subsystem. [ABSTRACT FROM AUTHOR]

In order to resolve the starting problem for position sensorless interior permanent magnet synchronous motor, an improved initial rotor position estimation method based on square-wave signal injection is presented in this paper. Instead of the conventional sinusoidal voltage injection, square-wave voltage signals are injected into stator windings to obtain magnet pole position. On the basis of saturation and saliency principle, the voltage pulse injection method was adopted to identify the magnet polarity. Detecting the magnet pole position by using the square-wave voltage injection, the error signal can be calculated without low-pass filters and time delays. The proposed method is verified via a 1.5 kW interior permanent magnet synchronous motor drive platform. [ABSTRACT FROM AUTHOR]

This paper presents a novel position and speed estimation method for low-speed sensorless control of interior permanent-magnet synchronous machines (IPMSMs). The parameter design of the position and speed estimator is based on the sampled current rather than the motor electrical parameters. The proposed method not only simplifies the parameter design, it enables the estimator to work normally even in the condition that the electrical parameters are uncertain or varied. The adaptive filters are adopted to extract the desired high frequency current. The structure and corresponding transfer function are analyzed. To address the shortage of insufficient stop-band attenuation, the structure of the adaptive filter is modified to provide suitable bandwidth and stop-band attenuation simultaneously. The effectiveness of the proposed sensorless control strategy has been verified by simulations and experiments. [ABSTRACT FROM AUTHOR]

At nonlinear field-weakening control of interior permanent magnet synchronous motor (IPMSM), the working point is difficult to calculate and the saturation of current regulators may lead to losing control. Linear field-weakening control (LFC) of IPMSM is proposed to control both torque and current in wide speed range applications and LFC can prevent loosing current control in IPMSM. IPMSM operation range is divided into three areas, namely constant torque linear area, constant power transition linear area, and constant direct axis current area. Current, speed, and torque of the three areas are obtained while maintaining the current and voltage constraints. Currents are controllable and the system can operate in deep field-weakening. Results are used to calculate the IPMSM working points. The validity of this study is verified by experiments. [ABSTRACT FROM PUBLISHER]

This paper presents a nonlinear sliding mode control (SMC) scheme with a variable damping ratio for interior permanent magnet synchronous motors (IPMSMs). First, a nonlinear sliding surface whose parameters change continuously with time is designed. Actually, the proposed SMC has the ability to reduce the settling time without an overshoot by giving a low damping ratio at the initial time and a high damping ratio as the output reaches the desired setpoint. At the same time, it enables a fast convergence in finite time and eliminates the singularity problem with the upper bound of an uncertain term, which cannot be measured in practice, by using a simple adaptation law. To improve the efficiency of a system in the constant torque region, the control system incorporates the maximum torque per ampere (MTPA) algorithm. The stability of the nonlinear sliding surface is guaranteed by Lyapunov stability theory. Moreover, a simple sliding mode observer is used to estimate the load torque and system uncertainties. The effectiveness of the proposed nonlinear SMC scheme is verified using comparative experimental results of the linear SMC scheme when the speed reference and load torque change under system uncertainties. From these experimental results, the proposed nonlinear SMC method reveals a faster transient response, smaller steady-state speed error, and less sensitivity to system uncertainties than the linear SMC method. [ABSTRACT FROM AUTHOR]

In this paper, an interior permanent magnet (PM) synchronous motor (IPMSM) with concentrated windings was designed for railway traction applications. This IPMSM was analyzed using a 2-D FEM. The results showed that the designed IPMSM has a significant PM eddy-current loss. For more accurate calculation, a 3-D FEM analysis was carried out. Further, the PM eddy-current loss was reduced without critical torque reduction by changing the position of the magnets at the rotor. Finally, frequency analysis of air-gap magnetic flux density waveforms was carried out to investigate the effect of magnet placement on the eddy-current loss. [ABSTRACT FROM AUTHOR]

The highly efficient Interior Permanent Magnet Synchronous Motor (IPMSM) is ubiquitous choice in Electric Vehicles (EVs) for today's automotive industry. IPMSM control requires accurate knowledge of an immeasurable critical Permanent Magnet (PM) flux linkage parameter. The PM flux linkage is highly influenced by operating temperature which results in torque derating and hence power loss, unable to meet road loads and reduced life span of electrified powertrain in EVs. In this paper, novel virtual sensing scheme for estimating PM flux linkage through measured stator currents is designed for an IPMSM centric electrified powertrain. The proposed design is based on a Uniform Robust Exact Differentiator (URED) centric Super Twisting Algorithm (STA), which ensures robustness and finite-time convergence of the time derivative of the quadrature axis stator current of IPMSM. Moreover, URED is able to eliminate chattering without sacrificing robustness and precision. The proposed design detects variation in PM flux linkage due to change in operating temperature and hence is also able to establish characteristics of fault detection. The effectiveness and accuracy in different operating environments of the proposed scheme for nonlinear mathematical IPMSM model with complex EV dynamics are verified thorough extensive simulation experiments using MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

In order to realize precise rotor position/speed control of ac motor drives under sensorless operation, motor parameters should be online estimated. In this paper, the identification on permanent magnet flux of interior permanent magnet synchronous motor (IPMSM) under position sensorless control is investigated. A rotor-flux-oriented vector control with model reference adaptive system (MRAS)-based rotor position/speed estimation is employed as the basic control strategy for IPMSM drive. An identification scheme based on extended Kalman filter for the permanent magnet flux of IPMSM is proposed. By using this scheme, the identification problems due to low-order state equations of IPMSM can be avoided. Based on these works, the online permanent magnet flux identification of IPMSM with rotor position/speed senseless control is realized. Simulation and experimental results demonstrate the feasibility and effectiveness of the proposed control methods, which shows that the estimation error of rotor position based on the identified permanent magnet flux is limited within a very low level. [ABSTRACT FROM PUBLISHER]

The interior permanent magnet synchronous motor (IPMSM) is usually applied to the traction motor in the hybrid electric vehicle and the electric vehicle due to its high-power density and wide speed range. In this paper, the IPMSM with concentrated winding for a 110 cc electric motorcycle is introduced. Its design was improved for high efficiency and a wide speed operation range. The output characteristics were also analyzed according to the partial magnetic saturation of the shoe and web in many variables. Because partial magnetic saturation affects the harmonics and the eddy current loss of the permanent magnet, it was confirmed that the output characteristics of the motor significantly changed. As a result, the new shape and the design parameters for which the partial magnetic saturation was considered were obtained. Higher level efficiency and a wider operating range than with the base model were confirmed. [ABSTRACT FROM AUTHOR]

Integrated starter and generator (ISG) is working as starter after vehicle idle stopping and generator during vehicle driving. When ISG works as starter to operate engine, ISG produces maximum power at the operating speed 4000 rpm to remove vibration of initial starting of the engine. In that time ISG produces whine noise which can be detected inside a vehicle. There are two methods to reduce the vibration and noise. One is improving the stiffness of stator and the other is reduction of electromagnetic exciting force. Although improvement of stiffness using mechanical design is utilized effectively to reduce whine noise, the electromagnetic design using the reduction of exciting forces is more reasonable in the same motor size. Because ISG produces torque ripple, radial force and tangential force on operating condition, this paper deals with the reduction design of electromagnetic exciting forces which affect the noise and vibration. Two design variables are selected to optimize the rotor shape especially geometry of flux barrier, and response surface methodology (RSM) is applied as an optimization method. Finally, quantity of the vibration and noise of optimized model are compared with prototype model, and the noise measured in the vehicle engine bay was reduced from 27 dB(A) to 25 dB(A). [ABSTRACT FROM AUTHOR]

In an interior permanent magnet synchronous motor, an adhesive such as bond is generally injected into the magnet tolerance to prevent vibration of the permanent magnet within the insertion space. In this case, a disadvantage is that the magnet tolerance does not contribute to the performance. In this paper, ferrofluid is inserted to improve the torque density, utilizing the magnet tolerance. When inserting ferrofluid into the magnet tolerance, it is important to fix the magnet because conventional adhesives are not used, and it is important that the ferrofluid does not act as a leakage path within the insertion space. In this study, a new rotor configuration using a plastic barrier that satisfies these considerations was introduced. The analysis was conducted through finite element analysis (FEA), and this technique was verified by comparing the simulation results and the experimental results through a dynamo test. It was confirmed that the no-load back electromotive force in the final model increased through ferrofluid injection. [ABSTRACT FROM AUTHOR]

An interior permanent magnet synchronous motor (IPMSM) drive system with machine learning-based maximum torque per ampere (MTPA) as well as flux-weakening (FW) control was developed and is presented in this study. Since the control performance of IPMSM varies significantly due to the temperature variation and magnetic saturation, a machine learning-based MTPA control using a Petri probabilistic fuzzy neural network with an asymmetric membership function (PPFNN-AMF) was developed. First, the d-axis current command, which can achieve the MTPA control of the IPMSM, is derived. Then, the difference value of the dq-axis inductance of the IPMSM is obtained by the PPFNN-AMF and substituted into the d-axis current command of the MTPA to alleviate the saturation effect in the constant torque region. Moreover, a voltage control loop, which can limit the inverter output voltage to the maximum output voltage of the inverter at high-speed, is designed for the FW control in the constant power region. In addition, an adaptive complementary sliding mode (ACSM) speed controller is developed to improve the transient response of the speed control. Finally, some experimental results are given to demonstrate the validity of the proposed high-performance control strategies. [ABSTRACT FROM AUTHOR]

This paper reports the optimal control problem on the interior permanent magnet synchronous motor (IPMSM) systems. The control performance of the traditional model predictive control (MPC) controller is ruined due to the parameter uncertainty and mismatching. In order to solve the problem that the MPC algorithm has a large dependence on system parameters, a method which integrates MPC control method and parameter identification for IPMSM is proposed. In this method, the d-q axis inductances and rotor permanent magnet flux of IPMSM motor are identified by the Adaline neural network algorithm, and then, the identification results are applied to the predictive controller and maximum torque per ampere (MTPA) module. The experimental results show that the optimized MPC control proposed in this paper has a good steady state and robust performance. [ABSTRACT FROM AUTHOR]