Prototyping of IPMSMs for a Micro-mover and Their d-q Equivalent Model Based Comparative Evaluation

This study proposes an on-line minimum loss (ML) control strategy that considers the iron and copper losses of an interior permanent magnet synchronous motor in torque-controlled applications. The proposed ML control strategy utilizes a constrained optimization problem to satisfy torque reference tracking and loss minimization. An equivalent iron loss resistance circuit is adopted for the loss minimization. To solve the optimization problem, the Lagrange multiplier method is applied through a numerical analysis algorithm. The resulting solution provides the optimal current reference for every sampling instant. The Lagrange multiplier method needs parameters such as magnetic flux linkages, dynamic inductances, and iron loss resistance. Fundamental magnetic flux linkages are estimated using a flux observer, and the dynamic inductances are estimated with high-frequency voltage signal injection. The proposed iron loss resistance estimator estimates the equivalent iron resistance without any preliminary experiments. DC input power is measured using a current sensor for the accurate on-line estimation of iron loss resistance. To analyze the effectiveness of ML control compared with conventional maximum torque per ampere control, finite element analysis is used. The feasibility of the proposed ML control strategy is verified through simulation and experiments.

Vacuum cleaner motors need to be capable of providing high power and high efficiency during high-speed (e.g. 50,000 r/min) operations. Because of this, interior permanent magnet synchronous motors (IPMSM), while highly efficient under general operating conditions, are not normally considered suitable for use in vacuum cleaners because of their tendency to suffer from severe iron loss during high speed operations. These losses have a severe negative impact on motor efficiency. In this research, we examine efforts to reduce iron loss during high-speed IPMSM operations. It is expected that the iron loss of slotless IPMSM operating at high speeds can be greatly decreased because there are no teeth in the area where the magnetic flux density is high. Performance comparisons between slotless IPMSM and conventional IPMSM (which utilize distributed windings) are then performed.

The interior permanent magnet synchronous motors (IPMSMs) are extensively applied in the field of new energy vehicles due to their high-power density and excellent performance control. However, the iron loss has a significant impact on their performance. This study conducts an optimization analysis on the processing technology of silicon steel sheets and motor structure, targeting the reduction of iron loss and the improvement of the motor’s integrated efficiency. Firstly, the influences of two iron core processing technologies on iron loss, namely gluing and welding, are compared. Through experimental tests, it is found that the iron loss density of the gluing process is lower than that of the welding process, and as the magnetic flux density increases, the difference between the two is expanding. Therefore, the iron loss test data from the adhesive process are employed to develop a variable-coefficient iron loss model, enabling precise calculation of the motor’s iron loss. On this basis, aiming at the problem of excessive iron loss of the motor, a novel topological structure of the stator and rotor is proposed. With the optimization goal of reducing the motor iron loss and taking the connection port of the air magnetic isolation slot and the gap of the stator module as the optimization variables, the optimized design of the IPMSM with low iron loss is achieved based on the Taguchi method. After optimization, the stator iron loss decreases by 13.60%, the rotor iron loss decreases by 20.14%, and the total iron loss is reduced by 15.34%. The optimization scheme takes into account both the electromagnetic performance and the process feasibility, it offers technical backing for the high-efficiency operation of new energy vehicle drive motors.

The adoption of Interior Permanent Magnet Synchronous Motors (IPMSM) and Synchronous Reluctance Motors (SynRM) is gaining popularity in many fields, including simple industrial applications, where cost and efficiency are the main aspects. In those applications, sensorless control is usually desired and commissioning should be simple and relatively fast. While specific-purpose drives have been successfully addressed by sensorless drives based on PMSMs and SynRMs, the integration of these techniques in general-purpose drives is still limited and, when available, mostly linked to proprietary techniques. In fact, motor parameters are needed for tuning control parameters or characteristics, which are only partially available from standard nameplates. Moreover, manual setup requires specialized knowledge and can be very time consuming. In order to remove these barriers towards wider adoption of these efficient motors, considerable research effort is being devoted to fully automate the commissioning, i.e. “auto-tuning” of the drive. This paper proposes and analyzes a feasible way to obtain complete self-commissioning of a mid-performance IPMSM or SynRM drive.

For electric vehicles (EVs), permanent magnet synchronous motors (PMSMs) are competitive owing to their high power factor, high efficiency and high power density. In this paper, four types of PMSMs with different rotor topologies are designed with the same motor main dimensions and the same amount of permanent magnet usage. First, the different PMSMs are compared in terms of their torque characteristics. The torque characteristic curves of the four motors are displayed with the control method i <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> =0 for surface-mounted PMSM (SPMSM) and Maximum Torque per Ampere (MTPA) for interior PMSM (IPMSM). It turns out that IPMSM has higher starting torque than SPMSM due to the reluctance torque. Among the three IPMSMs with different rotor structures, V-shape IPMSM and delta-shape IPMSM can provide higher output torque under the same current supply with the higher salient rate. More information on the no-load magnetic density, torque ripple, efficiency and demagnetization problem operated at the peak current is also provided and compared. Then the four PMSMs with the same peak current are further analyzed and compared on the flux-weakening speed-enlarge (FWSE) capability. The results show good FWSE capability for all of the four PMSMs owing to the large peak current. However, the torque of SPMSM in flux-weakening control region is slightly higher than the IPMSMs.

Synchronous homopolar motors (SHMs) with an excitation winding located at the stator and a toothed salient pole rotor are a good alternative to motors traditionally used in traction applications such as induction motors or interior permanent magnet synchronous motors (IPMSM). This study presents the results of a theoretical comparison between an IPMSM and an SHM in a traction application with a constant power speed range of 1:10, which is specific to the mining truck drives, and with a rated power of 370 kW. The considered IPMSM and SHM have the same number of phases, poles and stator slots, and the same outer diameter of the stator lamination. The IPMSM design is optimized using the Nelder–Mead method. The main objectives of optimization are to minimize the average losses in the operating cycle and to limit the required power of the semiconductor inverter. The performance of the optimized IPMSM is compared with the previously obtained performance of the SHM optimized by the same method. Although the average losses in the operating cycle in the compared motors are approximately equal, the losses at high speed for the IPMSM are about two times greater than at low speed with maximum torque, which means that there is a need to intensify the IPMSM cooling system and there is deterioration of reliability. The advantage of the IPMSM is the reduction in the length of the active part by 30%. The advantage of the SHM is that there is 4.6 times lower cost of active materials. In addition, the SHM is more reliable than the IPMSM, as there is no risk of overheating, demagnetization or degradation of permanent magnets over time.

This paper presents a sliding mode controller for an interior permanent magnet (IPM) synchronous motor, in which direct torque control (DTC) concept, variable structure control and space vector modulation (SVM) are integrated to achieve high performance. In comparison with conventional DTC, the inverter switching frequency is constant and controllable by using SVM, the torque and flux ripple are significantly reduced. The fast response and robustness merits of DTC are preserved. Position and angular speed of the rotor are obtained through an extended Kalman filter (EKF).

A study on the iron-loss reduction of 110kW-class Interior Permanent Magnet Synchronous Motor (IPMSM) for Light Railway Transit (LRT) is conducted. In general, the iron loss of IPMSM depends on the characteristics of core material and non-oriented electrical steel is used as a core material of IPMSM. In order to reduce the iron-loss of IPMSM, both non-oriented electrical steel and grain oriented electrical steel are applied as core material. Iron loss of 110kW-class IPMSM can be reduced approximately 40% comparing to an existing IPMSM by applying grain oriented electrical steel to the stator teeth.

This paper investigates the iron loss and torque characteristics of inverter-fed spoke type interior permanent magnet synchronous motor (IPMSM) optimized for sinusoidal distributed back-EMF. First of all, an optimal design procedure is introduced to effectively optimize the rotor pole surface to reduce the distortion of back-EMF in the spoke type IPMSM. Then, the finite element method (FEM) results for our optimized model and a circuit/control simulator for vector control are linked to analyze the nonlinearity of the motor and the control property of the motor drive.

Recently, means of transportation with electrical motors such as electric vehicles and ships are rapidly increasing. Various attempts have been made to reduce the size of the motors to increase the freedom of transport equipment system layouts and the energy efficiency of their transportation. Interior permanent magnet synchronous motors (IPMSMs) can realize higher torque than surface permanent magnet synchronous motors (SPMSMs) by using reluctance torque caused by magnetic saliency in addition to magnet torque. In comparison with SPMSMs, IPMSMs can have wide operation ranges by applying control methods such as maximum output control and field weakening control. Therefore, IPMSMs are expected to be used for a variety of application such as electric vehicles, ships and heavy equipment. By replacing permanent magnets with bulk superconductors in the rotors of IPMSMs, the magnet torque increases due to the stronger magnetic field of magnetized bulk superconductors. This leads to an increase in total torque density of the motors and contributes to motor size reduction. In this research, we propose an IPMSM with bulk superconductors with the goal of increasing the mechanical output density. In the proposed IPMSM, cooling space is left inside the rotor to cool the bulk superconductors to their superconducting state. Here, analysis based on finite element method was carried out to verify the utility of the proposed motor. First, the design of the motor with bulk superconductors and cooling space is discussed. It is shown that the total torque can be increased by adjusting the position of the bulk superconductor and modifying the structure of the flux barrier. The maximum total torque shown here was 22500 Nm. Then, the mechanical output density of the proposed IPMSM is compared with a conventional IPMSM. It is shown that the mechanical output density of the proposed IPMSM is 38% higher than the conventional IPMSM. Finally, the magnetic shielding effect, which might be a problem when using bulk superconductors, is discussed. By using electromagnetic analysis, it is shown that the external magnetic flux is weakened by the cooling space to several percent of the magnets’ surface and the effect of the shielding current is trivial.

The increase of pole numbers of the interior permanent magnet (IPM) synchronous machine can boost its air gap flux density, raise its efficiency and torque, and reduce its volume and weight. With the help of geometry module, this paper analyzes the relation between "flux concentration function" and the pole pair numbers of IPM synchronous machine, discusses connections between pole numbers and air gap flux density, per pole flux, non-load electric potential, flux density of rotor lead magnet material, flux density of stator tooth, flux density of stator yoke, and power which permanent magnet of unit volume produce respectively. Finally, authors point out: (1) when the saturation of lead magnet material was considered, the air gap flux density and the sums of the per pole flux will produce a the maximum with the increase of pole pairs, that is, IPM machine has a suitable pole pairs; (2) IPM machine bears "flux concentration function", when its pole pairs is more than or equal to 3, B/sub /spl delta///B/sub M/>1 or 4, B/sub /spl delta///B/sub r/>1; (3) the pole pairs of the IPM machine, which be from 3 to 6, is suitable. (4) the inner flux density of permanent magnet and power produced by the permanent magnet of unit volume will drop with the increase of pole pairs of the IPM machine.

In this paper, a power factor corrected Permanent Magnet Synchronous motor (PMSM) drive is discussed in detail. The wide variety of applications of PMSM drives makes it necessary to achieve fast and reliable drive control system design. This paper presents an analytical modeling of Surface Permanent magnet Synchronous motor (SPMSM) and Interior Permanent magnet Synchronous motor (IPMSM). A PI-controller based closed-loop Volts/hertz (V/F) controller is designed. It is based on Field Oriented Control (FOC) algorithm and operates in constant torque region. The controller is designed to ensure that the three phase IPMSM is operated close to unity power factor for wide speed range. IPMSM is designed and modeled using MATLAB/Simulink environment. The performance of the motor is evaluated in terms of power factor, total harmonic distortion and efficiency. Furthermore, a comparative analysis is done to validate the efficacy of IPMSM.

In order to improve the performance, efficiency and reliability of the interior permanent magnet synchronous motor (IPMSM) drive, a set of control strategies are developed for wide speed range operation. 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. A control strategy named maximum torque per ampere (MTPA) is applied to minimize the motor current magnitude during low speed operation. While an over-modulation method is employed to enhance the voltage transfer ratio of PWM inverter and the output torque capability of IPMSM during high speed operation, and flux weakening control is developed for high speed stable operation of IPMSM drive. Furthermore, phase current reconstruction under overmodulation is taken into account, which lowers the system cost and expands the working range of PWM inverter fed IPMSM motor drives. The issue of seamless switching from MTPA during low speed range to conventional field-weakening control during high speed range is also discussed. Simulation and experimental results demonstrate the feasibility and effectiveness of these control strategies, which realizes the high performance operation of IPMSM drive in wide speed range.

In this paper, the iron loss was calculated using estimated iron loss coefficient at 650W Interior Permanent Magnet Synchronous Motor(IPMSM) and 250W IPMSM. The iron loss coefficients was estimated different according to electrical steel material used to stator and rotor core in motor. Aspect of The rotating flux field and alternating flux field was confirmed by magnetic field behavior and harmonic analysis in stator core, the iron loss was calculated using flux density by Finite Element Method(FEM) and estimated coefficients by iron loss coefficient estimation proposed in this paper. The iron loss experiment was performed for verified to iron loss calculation, and the iron loss coefficients were verified by comparison of iron loss calculation value and experimental value.

This article presents the design studies of a multi‐layer interior permanent magnet synchronous motor (IPMSM) with a radially oriented arc‐shaped hot‐deformed magnet for automotive traction drives. Specifically, by using the IPMSM on a 2010 Prius as a benchmark, we designed an IPM rotor geometry that simultaneously achieves a 20% improvement in both the maximum power and constant output power line with high efficiency while maintaining maximum torque. A prototype of the designed three‐layer IPMSM was manufactured and evaluated. The results of the tests conducted on the prototype are reported and discussed in this article.