Permanent Magnet Brushless Motor Research Articles

Design, Modeling, and Control of a Brushless Permanent Magnet Motor for Electric Vehicles

Electric Vehicles (EVs) are becoming more and more common. In addition to their ecological advantages, EVs have demonstrated their efficiency in curtailing travel expenses by transitioning from gasoline to electricity, which is significantly less costly. This study proposes a Brushless Permanent Magnet Motor (BPMM) design for EVs, models the influence of average and ripple torque, and evaluates its efficiency compared to other designs. The validity of the proposed design was supported by simulation results.

Research on Motor Drive Technology for an Operating Device of 126 kV Vacuum Circuit Breaker

This study has designed a set of motor operating devices for a 126 kV vacuum circuit breaker (VCB) to improve its reliability and controllability. A finite‐angle permanent magnet brushless motor (FAPMBM) with a multi‐slot stator structure and a dovetail rotor structure has been designed based on the torque and speed requirements of the motor. These requirements were determined by a dynamic analysis of the operating device and its short‐time, finite‐angle working characteristics. The work performance of the prototype motor has been evaluated in an online experiment with a 126 kV VCB, and based on this, a segmented control method has been designed. The motion process of the operating device has been divided into four stages in combination with the output torque demand of the driving motor. At each stage, the output torque of the motor has been changed dynamically to prevent contact collision, shorten the pre‐breakdown time, and make the circuit breaker work more reliably. The results show that the FAPMBM can meet the operating time and speed requirements of the interrupter for the operating device. In addition, the segmented control method improves the work reliability and optimizes the movement of the operating device, which helps the circuit breaker work intelligently. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

An optimal selection of slot/pole combination and its influence on energy efficient PMSM for submersible water pumping applications

In India, some states have a depth of ground water reaching beyond 300–450 m from the ground level. Traditionally, submersible induction motor (SIM)-based pump sets are considered for irrigation. However, SIMs are no longer a good choice for deep bore wells, since there exists a reduction in its operating point, resulting in lower discharge. Based on these facts, submersible brushless permanent magnet motor (SBLPMM) is considered. The proposed SBLPMM is designed for 15 kW with an objective of high torque and power density within the given volumetric and diametric constraints. The proposed SBLPMM will reduce the number of impeller stages when compared with SIMs and hence it will be a viable alternative to the SIMs and hence paying the way for effective energy conservation. The study concentrates on the optimal selection of the geometrical poles and the finite element mesh-based results confirm that the operating efficiency is enhanced with the SBLPMM.

Performance Analysis of Magnetically Geared Permanent Magnet Brushless Motor for Hybrid Electric Vehicles

The magnetic field modulated variable speed permanent magnet (PM) brushless motor (MFMVS-PMBM) is a new type of power shunting device for hybrid electric vehicles (HEVs), which is composed of a magnetic gear (MG) and a PM brushless motor (PMBM). Compared with the conventional double rotor motor, the MFMVS-PMBM shows a more complex electromechanical energy conversion relationship due to its special magnetic field modulation principle. In order to obtain better electromagnetic characteristics of the motor, the key parameters of MG and PMBM are optimized in this study. The effects of gear ratio, the number of blocks per pole of the Halbach array, and the angle of connecting bridge and magnetic isolation bridge on the torque of MG are analyzed. The electromagnetic characteristics of the motor, such as pole slot matching, PM thickness, and slot opening width of PMBM, are also analyzed. Finally, the prototype is made, and the experimental platform is built. The results show that MFMVS-PMBM has a good sinusoidal back electromotive force (EMF), high transmission efficiency, and power factor.

A Magnetic Field Modulated Permanent Magnet Brushless Motor with MgB2

A Magnetic Field Modulated Permanent Magnet Brushless Motor with MgB2

Магнитные вибрации сердечника статора магнитоэлектрического вентильного двигателя

The radial and tangential tensions causing force effects on the stator core are considered as applied to a 150 kW brushless permanent magnet motor. The orders of tension waves, their displacement velocities, and the frequencies of forced force actions are analyzed. The electromagnetic torques of tangential tensions are investigated. It is shown that with non-sinusoidal excitation of the rotor, same-order higher harmonics of the magnetic induction from the rotor magnets and stator currents cause high-frequency electromagnetic torques. Three resonant frequencies of the stator core at radial magnetic forces are calculated. The stator core radial displacement amplitudes and vibration velocities were determined, which have been found to be close to experimental data. An experimental frequency response of the motor casing noise for its idle operation mode is obtained. Comments regarding the sources of noise bursts occurring at a number of frequencies are given. The influence of insufficiently suppressed high-frequency reactive torque (the "walking" torque) on the motor noise is pointed out. It is shown that the presence of a residual reactive torque with an amplitude measured from experiment leads to a rather high burst of motor casing noise at a frequency of 3500 Hz.

Frequency Analysis of Partial Short-Circuit Fault in BLDC Motors with Combined Star-Delta Winding

This paper analyses the condition of a partial short-circuit in a brushless permanent magnet motor. Additionally, the problem was analysed for three stator winding configurations: star, delta and star-delta connection. The paper presents an original mathematical model allowing a winding configurations to be analysed. What is more, the said mathematical model allows taking account of the partial short-circuit condition. Frequency analysis (Fast Fourier Transform—FFT) of the artificial neutral point voltage was proposed for the purpose of detecting the partial short-circuit condition. It was demonstrated that a partial short-circuit causes a marked increase in the diagnostic frequencies of the voltage signal. The proposed brushless permanent magnet motor diagnostic method is able to detect the fault regardless of the stator winding configuration type.

An integrated permanent magnet brushless motor driver with commutation current ripple reduction

An integrated permanent magnet brushless motor driver with commutation current ripple reduction

Square-wave drive for synchronous reluctance machine and its torque ripple analysis

Synchronous reluctance machine (SynRM) can be perceived as a special type of permanent magnet synchronous machine (PMSM), and shares similar control method, i.e. the sine-wave current drive with sinusoidal phase currents. In this paper, square-wave drive, which is employed for permanent magnet brushless (BLDC) motors, is employed for the SynRM, in order to economically reduce the cost of rotor position sensor. It is revealed that the torque density and efficiency are slightly sacrificed, whereas torque ripple is deteriorated, proving the SynRM with square-wave drive still promising for the cost-sensitive application if torque ripple is not considered as a critical issue. To further investigate the additional pulsating torque under square-wave drive, mathematical model based on a-b-c phase inductance and d-q axis inductance are established, together with the time-stepping FE calculated currents. It is concluded that the harmonics in the currents tend to cause non-sinusoidal variation of the magnetic reluctance, which can be represented as additional inductance harmonics. The harmonics of the current and inductance interact with each other, thus undesirable torque ripple components are produced.

Effect of Manufacturing Influences on Magnetic Performance Parameters of Sub-Fractional Horsepower Motors

Depending on the stator lamination manufacturing processes (e.g., punching, laser cutting, clamping, welding, interlocking, and bonding), the motor’s magnetic performance parameters, such as cogging torque, hysteresis torque, and iron losses, can vary significantly. In sub-fractional horsepower (SFHP) permanent magnet motors, the manufacturing influence is typically even more severe because, due to their small dimensions, practically, the whole stator material is likely to be affected. This article analyzes the magnetic performance parameters cogging torque, hysteresis torque, and iron losses of three different stator lamination stacks (i.e., M250-35A punched with interlocking, M250-35A laser cut with bonding, and NO10 laser cut with bonding) of an SFHP single-phase brushless permanent magnet motor often found in automotive fan applications. A rheometer is used for extremely accurate torque measurements in the sub-millinewton meter range, and electron backscatter diffraction measurements are performed to visualize changes in the grain morphology and crystal orientation. The findings reveal that the punched stator with interlocking is affected the most by the manufacturing process, showing the lowest cogging torque yet the highest average hysteresis torque and thus up to 40% higher iron losses. The results presented in this article allow for both making basic stator lamination design choices and translating the iron losses, as well as the hysteresis torque and cogging torque waveforms, of a laser cut and bonded prototype into those of its punched and interlocked mass-produced counterpart.

Brushless DC Permanent Magnet Motors State of the Art

The paper presents a study of the permanent magnet brushless DC machine, from two perspectives - from authors’ own experience in designing and manufacturing such motors, as well as from actual published research. Various constructive topologies and how they influence BLDC operation, windings used with emphasis on slot, concentrated windings, are also presented. The following part describes current techniques used for enhancing BLDC limited maximum speed, such as phase advance and dwell control, somewhat similar to flux weakening in AC permanent magnet brushless motors. The paper concludes with presentation of several methods used for sensing BLDC rotor position. Overall, the authors’ intention publishing this paper was to provide an insight regarding current BLDC development, as well as to assist in making documented choices when using BLDC in specific applications.

Reusable Surrogate Models for the Preliminary Design of Aircraft Application Systems

This paper presents a new methodology for obtaining surrogate models suitable for the preliminary design of aircraft application systems. The methodology is based on a dimensional and sensitivity analysis adapted to the needs and constraints arising from multidisciplinary design. It enables simpler and lighter models to be obtained, with satisfactory predictive accuracy over a large range of validity. These surrogate models can cover a very large area of applications, where the components may vary from very small to very large sizes, because of their broad range of validity. Avoiding the reconstruction of the model offers advantages in terms of capitalization and justifying the concept of reuse. The proposed approach is applied to generate surrogate models of a permanent magnet brushless motor used in two types of applications: one is for the preliminary design of a flight control electromechanical actuator and the other is for the preliminary design of an electric propulsion system for a multirotor drone.

Design, Analysis, and Comparison of Control Strategies for an Industrial Robotic Arm Driven by a Multi-Level Inverter

In this article, we present the design and implementation of different control strategies for the position of a 2-Degree-of-Freedom (DoF) robotic arm, namely gain scheduling per trenches, gain scheduling by interpolation, adaptive control, and fuzzy logic. The first link of this robot is driven by an Alternating Current Brushless Permanent Magnet Motor (ACBPMM) through a three-phase multi-level inverter with 27 levels of voltage per phase. Thanks to the topologies offered by ACBPMMs and to the multi-level inverter, high commutation frequencies are reduced, as observed in the computer simulations. Additionally, to determine which proposed control strategies are the most suitable for an ACBPMM connected to a multi-level inverter, a comparative study on the performance of the controllers implemented for this robot is conducted.

Design and calculation of sine wave permanent magnet brushless motor for electric vehicle

With the rapid development of the global automobile industry, energy and environmental problems have become increasingly prominent. In order to realize the sustainable development of new energy, automobile industry has become the direction of new energy. Due to the relatively mature energy storage technology, high efficiency of driving motor and mature control mode, electric vehicles have become the main development direction of new energy vehicles. The main work of this paper is to study the characteristics of various driving motors, design a motor which can meet the performance index of pure electric vehicle, and select an appropriate control scheme.

A Simple Analytical Model of Static Eccentricity for PM Brushless Motors and Validation through FEM Analysis

The paper firstly summarizes a simple analytical model of the air gap flux-density distribution for isotropic permanent magnet (PM) synchronous machines, in the presence of static eccentricity. The model was proposed by the authors in a previous paper and is based on an efficacious analytical expression of the variable length of air gap magnetic field lines which occur in eccentric brushless machines with surface-mounted permanent magnets. The approximate expression of the air gap field makes it possible to achieve a mathematical model with concentrated parameters close to that of a PM machine without eccentricity. The expression of the armature voltages and electromagnetic torque are found, also with reference to steady-state operating conditions at fixed rotor speed and impressed currents. The differences introduced by the considered type of eccentricity are evaluated and highlighted especially with reference to the air gap inductance and to waveforms and frequency spectra of voltages and shaft torque. Numerical results in a case-study of an 8-pole, 110 kW PM motor are compared to those obtained by using finite element analysis.

Zero-Sequence Current Suppression for Open-Winding Permanent Magnet Brushless Motor Driving System Based on Second Order Generalized Integrator

The open-winding driving system can improve power density and torque output capacity of the motor. However, the open-winding topology with a common direct current (DC) power supply provides a path for the zero-sequence current, which contributes to the power loss but not the torque output. The zero-sequence current is produced by the common-mode voltage and zero-sequence components of the back electromotive force (EMF). For the purpose of eliminating the common-mode voltage as well as improving the utilization of DC supply voltage, a 120° decoupling space vector pulse width modulation strategy is adopted. Meanwhile, a proportional unit combined with second order generalized integrator (SOGI) is proposed to suppress the zero-sequence current caused by the zero-sequence components of the back EMF. A test bench is built for the experiment. The effectiveness of the proposed suppression strategy is verified by the experimental results.

MOTORSOLVE SOFTWARE PACKAGE: VERIFICATION OF PARAMETERS AND CHARACTERISTICS OF THE BRUSHLESS PERMANENT MAGNET MOTOR

Purpose. The purpose of this paper is to include comparison of results of the modeling and calculation in the Mentor Siemens software MotorSolve and experiment of the brushless permanent magnet motor. Methodology. Numerical investigation using licensed software MotorSolve is performed. Calculations of motor parameters and characteristics are made using Finite Element Method. The experimental investigations were made on the hysteresis dynamometer AHD-603. Results. The results of the investigations show that the calculations of the parameters and characteristics of the motor in MotorSolve software almost match with the results of the experiments. Practical value. The high efficiency of the MotorSolve software for the modeling, calculation and research of the brushless permanent magnet motors are confirmed.

Design and Multi-Objective Stratified Optimization of a Less-Rare-Earth Hybrid Permanent Magnets Motor With High Torque Density and Low Cost

The price fluctuation and the unstable supply chain of rare-earth permanent magnet (PM) have posed potential risks for further application of rare-earth PM motors. To alleviate the consumption of rare-earth PM material, a less-rare-earth PM brushless motor with two types of PM materials is proposed in this paper. The key of this motor is that the rare-earth PM is purposely combined with a non-rare-earth ferrite PM, forming the hybrid PM excitation. To design the proposed motor efficiently, a multi-objective stratified optimization strategy is proposed, where the selected five optimization objectives of output torque, PM cost, cogging torque, torque ripple, and efficiency are divided into two levels. Then, different optimization methods are skillfully combined to meet the specific design requirements. The corresponding electromagnetic performances are analyzed and compared with the baseline rare-earth PM brushless motor. Finally, several experiments of the two motors are carried out for evaluation. Both theoretical analysis and experimental results verify the feasibility and validity of the proposed motor and the optimization method.

A Fast Phase Variable <inline-formula> <tex-math notation="LaTeX">$abc$</tex-math> </inline-formula> Model of Brushless PM Motors Under Demagnetization Faults

This paper addresses a simple and computationally efficient dynamic model for brushless permanent magnet (PM) motors under PM demagnetization faults. The impact of stator slots and spatial disposition of the windings are taken into account to improve the accuracy of a lumped-parameter $abc$ model. This model is suitable for tracking the dynamic behavior of fault components, as it can be accompanied by any control scheme and/or be used for model-based fault detection schemes. In addition, parameters of this model can be automatically tuned by an optimization process in the offline phase of the healthy machine. Finite-element simulations are carried out for proving the effectiveness of the proposed model. Verification is done in both time and frequency domains for four PM motors with different rotor and stator configurations. The simulation results are experimentally verified.

Analytical Energy-Based Approaches for Cogging Torque Calculation in Surface-Mounted PM Motors

This paper deals with the cogging torque calculation in permanent-magnet (PM) surface-mounted machines based on energy approach. Three different analytical co-energy methods are assessed, and innovative computation techniques for calculating co-energy are applied to reduce the computations time and burden. Also, an air-gap function due to the slot is presented for the simple method. Then, the results achieved by the analytical methods are validated by the finite-element method (FEM). The cogging torque using such methods has a good agreement with FEM. Three case studies consisting of brushless PM (BLPM) motors with slotted stator structure are considered to show the efficiency of the proposed methods. Finally, different methods are compared in terms of their computational complexity and accuracy.