Conventional Permanent Magnet Synchronous Motor Research Articles

High-Efficiency e-Powertrain Topology by Integrating Open-End Winding and Winding Changeover for Improving Fuel Economy of Electric Vehicles

The fuel economy of electric vehicles (EVs) is an important factor in determining the competitiveness of EVs. Since the fuel economy is affected by the efficiency of an e-powertrain composed of a motor and inverter, it is necessary to select a high-efficiency topology for the e-powertrain. In this paper, a novel topology of e-powertrains to improve the fuel economy of EVs is proposed. The proposed topology aims to improve the system efficiency by integrating open-end winding (OEW) and winding changeover (WC). The proposed OEW-PMSM with WC enables to drive a permanent magnet synchronous motor (PMSM) in four different modes. Each mode can increase inverter efficiency and motor efficiency by changing motor parameters and maximum modulation index. In this paper, the system efficiency of the proposed topology was evaluated using electromagnetic finite element analysis and a loss model of power semiconductors. In addition, the vehicle simulations were performed to evaluate the fuel economy of the proposed topology, thereby proving the superiority of the proposed topology compared with the conventional PMSM.

Design and Optimisation of a 5 MW Permanent Magnet Vernier Motor for Podded Ship Propulsion

The evolution of electric propulsion systems in the maritime sector has been influenced significantly by technological advancements in power electronics and machine design. Traditionally, these systems have employed surface-mounted permanent magnet synchronous motors (PMSMs) in podded configurations. However, the advent of permanent magnet Vernier motors (PMVMs), which leverage magnetic gearing effects, presents a novel approach with promising potential. This study conducts a comparative analysis between PMVMs and conventional PMSMs at a power level of 5 MW for podded ship propulsion, with a particular focus on the impact of gear ratios (Gr). An objective function was developed that integrates motor dimension constraints and the power factor (PF), a critical yet frequently neglected parameter in existing research. The findings indicate that PMVMs with lower Gr have lower mass and cost compared to those with higher Gr and traditional PMSMs, at a PF level of 0.7, which is high for Vernier machines. Moreover, PMVMs with lower Gr achieve efficiencies exceeding 99%, outperforming both their higher Gr counterparts and conventional PMSMs. The superior performance of PMVMs is attributed to lower current density and reduced copper loss, which contribute to their enhanced thermal performance. These details are elaborated on further in the paper. Consequently, these findings suggest that PMVMs with lower Gr are particularly well suited for high-power maritime propulsion applications, offering advantages in terms of compactness, efficiency (EF), cost-effectiveness, and thermal performance.

A Review on the Fault-Tolerant Method of PMSM using Finite Element Method by Modifying Phase Angle for EV Applications

Abstract: The present research reviews a fault-tolerant technique for Permanent Magnet Synchronous Motors (PMSMs) that involves phase angle adjustment. Fault tolerance standards for the motor used in electric vehicles are necessary due to the rapid development of these vehicles. The primary option for electric vehicle drive motors is increasingly being replaced with permanent magnet synchronous motors (PMSM), which have minimal torque ripple, great durability, and other benefits. After comparing a six-phase PMSM to a conventional three-phase PMSM, the performance following a phase open is examined. A fault-tolerant technique for modifying the left phase current's phase angle to reduce torque ripple following a phase open is then described. The finite element simulation indicates that the six-phase PMSM's output torque ripple is reduced, and the fault-tolerant technique that is being described can further reduce the torque ripple.

Double-hierarchical fuzzy exponential convergence law fractional-order sliding mode control for PMSM drive control in EV

In the vector control of permanent magnet synchronous motor (PMSM), the speed overshoot and torque pulsation phenomena need to be solved. There are two prerequisites for the drive control of PMSM in electric vehicle (EV). The first is that the vehicle control has to be ensured as a whole. The second is, to ensure the economy of the vehicle control while ensuring the stable control of the motor. Therefore, this paper first proposes the fuzzy exponential convergence law fractional-order sliding mode control (F-CFSMC), it is constructed with the purpose of online correction of the exponential convergence law of the fractional-order sliding mode surface. It is expressing the arrival time and convergence speed of the fractional-order sliding mode surface explicitly with parameters. The stability of the F-CFSMC is proved to be derived using the Lyapunov equation. The F-CFSMC is applicable to PMSMs with different parameters. Next, the fuzzy controller that considers the battery parameter factor in EV is introduced to combine the lithium battery and PMSM to enhance energy utilization. At this point, the double-hierarchical fuzzy exponential convergence law fractional-order sliding mode control (DF-CFSMC) build is complete. Moreover, comparative simulations and experiments using the DF-CFSMC and the conventional PMSM control are conducted, and the results are performed in PMSM hierarchical. Simulations are also performed in the EV hierarchical application to show the universality, repeatability and advantages of DF-CFSMC.

Performance Validation of PM Assisted SynRM and PMSM with Optimized Design for EV Application

This paper presents the comparison of Permanent Magnet-Assisted Synchronous Reluctance Motor (PMASynRM) and Permanent Magnet Synchronous Motor (PMSM) for the same design parameters and the evaluation of various performance parameters based on the Finite Element (FE) Method. FE Analysis is conducted after selecting the optimized design for PMASynRM and PMSM using an FE tool, with loading conditions to determine various performance parameters. This is achieved by maintaining the same motor dimensions and stator parameters while altering the rotor geometry for both motors. The final simulation results are discussed, and other performance parameters are recorded for comparison purposes. A PMASynRM is introduced, in which the problems of Synchronous Reluctance Motor (SynRM) can be eliminated with a permanent magnet in the rotor flux barrier. Due to higher flux barriers in PMASynRM, the reluctance torque is higher than in PMSM. If the magnet is placed very near to the air gap in PMSM, higher magnet torque is achieved, but due to the high reluctance torque in PMASynRM, the electromagnetic torque of PMASynRM is higher compared to PMSM. The research proves that the proposed design of PMASynRM is the best choice for Electric Vehicle (EV) applications. For PMASynRM, the shape of the flux barrier is not possible to change due to the design limitation of the FE software tool. Further analysis can be conducted by changing the shapes of the flux barriers to propose the most effective barriers. Basic theory and FE analysis of conventional PMSM and SynRM are reported in the literature. An optimal design is proposed through comparative analysis for EV applications to find out the best candidate for an EV motor.

Investigation of Flux-Modulating Consequent Pole Motors

This article investigates the electromagnetic performance of a novel variable-flux permanent magnet (PM) motor, named the “flux-modulating consequent pole motor (FCM),” through finite element analysis (FEA) and experiments. The FCM is a combination of a flux-modulating (FM) motor and a consequent-pole PM motor, whose torque can be generated from both the FM and PM motors without causing unbalanced magnetic forces (UMFs). Two models with 16 and 20 poles are used to analyze the torque, efficiency, and power factor of the FCM. Moreover, efficiency maps of the FCM are compared with those of the conventional PM synchronous motors. It is revealed that the torque of the FCM depends on the values of winding factors of the FM and PM motors. Finally, experimental results on a 20-pole prototype machine are presented to validate the operating principle of the FCM and the FEA simulations.

Modeling and analysis of field-oriented control based permanent magnet synchronous motor drive system using fuzzy logic controller with speed response improvement

<span lang="EN-US">The permanent magnet synchronous motor (PMSM) acts as an electrical motor mainly used in many diverse applications. The controlling of the PMSM drive is necessary due to frequent usage in various systems. The conventional proportional-integral-derivative (PID) controller’s drawbacks are overcome with fuzzy logic controller (FLC) and adopted in the PMSM drive system. In this manuscript, an efficient field-oriented control (FOC) based PMSM drive system using a fuzzy logic controller (FLC) is modeled to improve the speed and torque response of the PMSM. The PMSM drive system is modeled using abc to </span><em><span lang="EN-US">αβ</span></em><span lang="EN-US"> and </span><em><span lang="EN-US">αβ</span></em><span lang="EN-US"> to abc transformation, 2-level space vector pulse width modulation (SVPWM), AC to DC rectifier with an inverter, followed by PMSM drive, <a name="_Hlk107566912"></a>proportional integral (PI) controller along with FLC. The FLC’s improved fuzzy rule set is adopted to provide faster speed response, less % overshoot time, and minimal steady-state error of the PMSM drive system. The simulation results of speed response, torque response, speed error, and phase currents are analyzed. The FLC-based PMSM drive is compared with the conventional PID-based PMSM drive system with better improvements in performance metrics.</span>

A novel flywheel energy storage system: Based on the barrel type with dual hubs combined flywheel driven by switched flux permanent magnet motor

With the challenges of global carbon emissions and climate warming, energy recovery and reuse are becoming very important. Flywheel energy storage system (FESS), as a kind of energy storage systems (ESSs), can effectively convert electrical energy and mechanical energy to accomplish energy recovery and reuse. Additionally, the FESS has the characteristics of pollution-free, high energy, high efficiency, and durability. Thus, a novel FESS is proposed for the configuration, metal material and structure, and driving motor (M/G) to contribute to the development of FESS. First, the novel FESS is made of the metal materials rather than the carbon fiber, reducing manufacturing difficulty and cost. Second, the structure of dual hubs combined flywheel is designed to reduce the mass and obtain a larger moment of inertia, achieving higher energy storage. Third, a 12/10 switched flux permanent magnet motor (SFPM) with an outer rotor structure is designed to replace the conventional permanent magnet synchronous motor (PMSM) and is used as the M/G to achieve excellent operation performance. Finally, the barrel type of the configuration makes the novel FESS more compact and facilitates the realization of a vacuum chamber to remove the windage. Undoubtedly, the novel FESS is designed through the theoretical calculation of energy storage, structure strength and modal analysis, and M/G performance simulation. Accordingly, the novel FESS has a maximum speed of 13,500 rpm, storage energy of 20 kWh (discharge depth 99%), and the longest power consumption time of 2 h. Equally, a prototype is manufactured and tested. Consequently, the results testify the mechanical properties are excellent, the charging and discharging action is stable and rapid.

Torque Characteristic of a Novel Tiered Type Permanent Magnet Spherical Motor

This article mainly investigates the torque characteristic of a novel tiered type permanent magnet spherical motor (T-PMSpM), which has the advantage of relatively larger torque ability compared with most existing spherical motors. The investigated T-PMSpM is capable of continuously rotating while the rotating shaft can tilt in all directions. Therefore, both the rotating torque and tilting torque need to be studied. Considering that the rotating principle is similar to the conventional permanent magnet synchronous motors, more attention is being paid to the tilting performance since it also decides the tilting range of the T-PMSpM. First, the key factors that significantly influence the tilting torque are found out based on the analytical expression of the tilting torque. Then, these key factors are analyzed aiming at expanding the tilting range as well as the magnitude of the tilting torque. Finally, the rotating torque is obtained and analyzed based on the above-optimized structure. The three-dimensional finite-element method is adopted for accurate calculation. A prototype motor of the T-PMSpM has been manufactured, and an experimental procedure is designed to measure the output torque for verification.

Flux and torque ripple minimisation for permanent magnet synchronous motor by finite‐set hybrid direct torque control

A hybrid direct torque control (DTC) method is proposed in this study for a permanent magnet synchronous motor (PMSM) drive based on the finite-set control (FSC). After selecting the optimal voltage vectors, the steady-state torque and flux ripple is minimised using the conventional DTC and the most efficient and dynamically-fast mode of the control algorithm. The philosophy of the control approach proposed is based on the FSC and DTC. In other words, the process of optimisation relies on a combination of FSC DTC. Compared to conventional PMSM drive control, the proposed technique optimises the switching state of the inverter and minimises the cost function by adopting measures resembling DTC. In addition, the sensitivity of this method to motor parameters is very low, and it is computationally simple. The results obtained from the experiments and simulations validated the applicability of this method to PMSM drives by suggesting that the proposed model provides dynamically-fast responses to low torque and flux ripples using a simple-to-implement hybrid structure.

Comparative Study on Variable Flux Memory Machines With Different Arrangements of Permanent Magnets

Compared with conventional permanent magnet synchronous motor, variable flux memory motor (VFMM) possesses the advantage of adjusting the magnetization state online. Because of its wide speed range and large high-efficiency region, it becomes a competitive candidate for the electric drive system. This paper presents a novel parallel hybrid magnets VFMM which is obtained by updating a conventional series hybrid permanent magnets VFMM. The proposed motor adopts a new permanent magnet arrangement and the combination of low coercive force permanent magnet and high coercive force permanent magnet is used. The proposed parallel hybrid permanent magnets VFMM and the series hybrid permanent magnets VFMM are compared. The equivalent magnetic circuit models of the motors are used to explain the principle of the motors. The finite element analysis method is used to study the fundamental properties, such as open circuit radial flux density, unintentional demagnetization with q-axis current, intentional demagnetization with d-axis current, torque capability, and efficiency characteristics. It was shown the efficiency of the parallel hybrid permanent magnets VFMM is higher in the high-speed region and the magnetization state adjustment range of the parallel hybrid permanent magnets VFMM is larger.

Modeling and Dynamics of HTS Motors for Aircraft Electric Propulsion

In this paper, the methodology of how a dynamic model of a conventional permanent magnet synchronous motor (PMSM) may be modified to model the dynamics of a high-temperature superconductor (HTS) machine is illustrated. Simulations of a typical PMSM operating under room temperature conditions and also at temperatures when the stator windings are superconducting are compared. Given a matching set of values for the stator resistance at superconducting temperature and flux-trapped rotor field, it is shown that the performance of the HTS PMSM is quite comparable to a PMSM under normal room temperature operating conditions, provided the parameters of the motor are appropriately related to each other. From these simulations, a number of strategies for operating the motor so as to get the propeller to deliver thrust with maximum propulsive efficiency are discussed. It is concluded that the motor–propeller system must be operated so as to deliver thrust at the maximum propulsive efficiency point. This, in turn, necessitates continuous tracking of the maximum propulsive efficiency point and consequently it is essential that the controller requires a maximum propulsive efficiency point tracking (MPEPT) outer loop.

A new self-propelled magnetic bearing with helical windings

In this work, a design is proposed for an active, permanent magnet based, self-propelled magnetic bearing, i.e. levitating motor having the following features: (i) simple winding structure, (ii) high load supporting capacity, (iii) no eccentricity sensors, (iv) stable confinement in all translational dimensions, (v) stable confinement in all rotational dimensions, and (vi) high efficiency. This design uses an architecture consisting of a helically wound three-phase stator, and a rotor with the magnets also arranged in a helical manner. Active control is used to excite the rotor at a torque angle lying in the second quadrant. This torque angle is independent of the rotor's position inside the stator cavity; hence the control algorithm is similar to that of a conventional permanent magnet synchronous motor. It is motivated through a physical argument that the bearing rotor develops a lift force proportional to the output torque and that it remains stably confined in space. These assertions are then proved rigorously through a calculation of the magnetic fields, forces and torques. The stiffness matrix of the system is presented and a discussion of stable and unstable operating regions is given.

Novel Dual-Layer and Triple-Layer Permanent-Magnet-Excited Synchronous Motors

This paper first presents a novel dual-layer permanent-magnet (PM)-excited (DPME) synchronous motor in which an extra set of iron teeth is employed in an inner stator between the PM rotor and the shaft. It can provide additional variation of magnetic reluctance along the circumferential direction of the air gap, and the strength of the flux modulation among the magnetic fields produced by the armature windings and the PMs is improved. The proposed motor has tactfully integrated the two pairs of flux-modulated motors inside one frame with one shared set of armature windings. The advantage of the proposed DPME motor is that it offers much higher torque capability than its conventional counterparts, making it more competitive for low-speed high-torque applications. In this paper, a novel triple-layer PM-excited (TPME) synchronous motor is further presented with the similar operating principle of the DPME, and it has three PM layers inside the frame. Finite-element method of magnetic field with mechanical motion coupled computation is employed to evaluate the electromagnetic torque precisely, showcasing that the proposed DPME motor can output an extra 37.5% more torque compared with a conventional synchronous motor, and the proposed TPME motor can output an additional 70% more torque with a similar power efficiency compared with the conventional PM synchronous motor.

Overview of Bearingless Permanent-Magnet Synchronous Motors

Bearingless permanent-magnet (PM) synchronous motors (BPMSMs) are a new type of machines combining the characteristics of conventional PM synchronous motors and magnetic bearings. With ever-increasing concerns on applications, such as high-speed electric machines, canned pumps, high-speed-precision mechanical processing, aeronautics and astronautics, flywheel energy storage, life science, vacuum technique, and semiconductor and biotechnology industries, there is a fast growing interest in BPMSMs. In this paper, after a general description of the generation principle of radial suspension forces, a comprehensive overview of BPMSMs is presented, with particular emphasis on mathematical models, motor topologies, and control strategies. Moreover, several possible development trends of the BPMSM are also discussed.

Novel Design for Direct Torque Control System of PMSM

Nowadays, with the rapid development of high-performance servo system, The conventional permanent magnet synchronous motor (PMSM) Direct Torque Control (DTC) system has large torque ripple in low speed which cannot be well adapted to today`s development. The main reason is because the number of voltage vectors provided by the two-level inverter is only six and the relationship between voltage vector and torque is not clear[1-5.10-12]. In this paper, the basic concept of direct torque control of permanent magnet synchronous motor is investigated in order to emphasize the effects produced by a given voltage vector on stator and torque variations in this paper. Modified the voltage sector switching table, a novel DTC scheme for the permanent magnet synchronous motor is proposed which is using a novel three-level inverter. An improvement of the drive performance can be obtained by using the novel DTC scheme. The simulation results showed that the scheme could reduce the torque ripple in low speed and improved the stability of the motor under the condition of keeping the system dynamic performance. DOI: http://dx.doi.org/10.11591/telkomnika.v11i4.2391

Permanent-Magnet Flux-Switching Synchronous Motor Employing a Segmental Rotor

This paper introduces a three-phase segmental-rotor flux-switching synchronous motor employing permanent-magnet (PM) excitation in the stator. Flux-switching machines operate with bipolar flux and flux linkages and are therefore associated with high torque densities. Employing a segmental rotor significantly alters the scheme for flux switching from that with toothed rotors but provides a means to deploy radially acting magnets in the stator teeth. The whole arrangement presents advantages of fault tolerance capability, brushless operation, easy cooling, and simplicity of construction. A three-phase motor is developed on a 12-tooth stator with six radial magnets and a rotor with eight segments. Design considerations are applied to the location and shape of the magnets. The developed design has attraction for low-cost applications as the torque capability per unit mass of magnets deployed is found to be about 1.4 times as much as that for conventional PM synchronous motors of the same general size. Measurement results on experimental machines show that the segmented-rotor motor with PM excitation can achieve nearly twice the torque density of the similar-sized segmented-rotor motor with a dc field winding.

Sliding mode control of chaos in the noise-perturbed permanent magnet synchronous motor with non-smooth air-gap

Permanent magnet synchronous motor (PMSM) is widely used in mining, and there exists chaotic behavior when it runs. In order to dispel its adverse effect on security in mining, the chaotic system of PMSM was analyzed. With noise disturbances, the complex dynamic characteristics of chaos were also analyzed, and proved the objective existence of chaos. As we all know, it is very difficult for conventional PMSM control to meet the design requirements, therefore, in order to ensure the robustness of the system, the chaotic orbits were stabilized to arbitrary chosen fixed points and periodic orbits by means of sliding mode method. Finally MATLAB simulations were presented to confirm the validity of the controller. The results show that the PMSM with the sliding mode control has a good dynamic performance and steady state accuracy.

Numerical assessment of efficiency and control stability of an HTS synchronous motor

A high temperature superconducting (HTS) permanent magnet synchronous motor (PMSM) is designed and developed in Cambridge University. It is expected to become cost competitive with the conventional PMSM owing to its high efficiency, high power density, high torque density, etc. The structure and parameters of HTS PMSM are detailed. Both AC losses by transport current and applied filed in stator armature winding of HTS PMSM are also analyzed. Computed and simulated results of the characteristics of the HTS PMSM and conventional PMSM are compared. The improvement on stability of direct torque control (DTC) on the HTS PMSM is estimated, and proved by simulation on Matlab/Simulink.

A Modular Control Scheme for PMSM Speed Control With Pulsating Torque Minimization

In this paper, a modular control approach is applied to a permanent-magnet synchronous motor (PMSM) speed control. Based on the functioning of the individual module, the modular approach enables the powerfully intelligent and robust control modules to easily replace any existing module which does not perform well, meanwhile retaining other existing modules which are still effective. Property analysis is first conducted for the existing function modules in a conventional PMSM control system: proportional-integral (PI) speed control module, reference current-generating module, and PI current control module. Next, it is shown that the conventional PMSM controller is not able to reject the torque pulsation which is the main hurdle when PMSM is used as a high-performance servo. By virtue of the internal model, to nullify the torque pulsation it is imperative to incorporate an internal model in the feed-through path. This is achieved by replacing the reference current-generating module with an iterative learning control (ILC) module. The ILC module records the cyclic torque and reference current signals over one entire cycle, and then uses those signals to update the reference current for the next cycle. As a consequence, the torque pulsation can be reduced significantly. In order to estimate the torque ripples which may exceed certain bandwidth of a torque transducer, a novel torque estimation module using a gain-shaped sliding-mode observer is further developed to facilitate the implementation of torque learning control. The proposed control system is evaluated through real-time implementation and experimental results validate the effectiveness.