Electric Vehicle Motor Research Articles

大規模マイクロマグネティックシミュレーションを用いた永久磁石の保磁力解析の最近の進歩と展望

The coercivity of permanent magnets is an important factor for the various applications including the electric vehicle motors. Improving the coercivity is highly demanded, however, it is quite sensitive to the microstructure of the magnet. For understanding the relation between the coercivity and the microstructure, the micromagnetic simulations of the permanent magnets have been studied extensively. Recently, as improving the computer performance and applying numerical techniques, such as the energy minimization, we can treat a multi-grain permanent magnet model in sub-micrometer scale. Hence, the effects of the magnetic grain size, the grain orientation and the magnetic properties of the grain boundary have been analyzed by the micromagnetic simulation. In addition, combining the micromagnetic simulation and the path analysis method make the thermal effect analysis enable. In this paper we summarize the foundation of the micromagnetic simulation for the coercivity analysis and review the studies on the coercivity analyses of the permanent magnet by using micromagnetic simulations.

Trends and Challenges in Electric Vehicle Motor Drivelines - A Review

Considering the need to optimize electric vehicle performance and the impact of efficient driveline configurations in achieving this, a brief study has been conducted. The drivelines of electric vehicles (EV) are critically examined in this survey. Also, promising motor topologies for usage in electric vehicles are presented. Additionally, the benefits and drawbacks of each kind of electric motor are examined from a system viewpoint. The majority of commercially available EV are powered by a permanent magnet motor or single induction type motors and a standard mechanical differential driveline. Considering these, a holistic review has been performed by including driveline configurations and different battery types. The authors suggest that motors be evaluated and contrasted using a standardized driving cycle.

Designing High-Power-Density Electric Motors for Electric Vehicles with Advanced Magnetic Materials

As we face issues of fossil fuel depletion and environmental pollution, it is becoming increasingly important to transition towards clean renewable energies and electric vehicles (EVs). However, designing electric motors with high power density for EVs can be challenging due to space and weight constraints, as well as issues related to power loss and temperature rise. In order to overcome these challenges, a significant amount of research has been conducted on designing high-power-density electric motors with advanced materials, improved physical and mathematical modeling of materials and the motor system, and system-level multidisciplinary optimization of the entire drive system. These technologies aim to achieve high reliability and optimal performance at the system level. This paper provides an overview of the key technologies for designing high-power-density electric motors for EVs with high reliability and system-level optimal performance, with the focus on advanced magnetic materials and the proper modeling of core losses under two-dimensional or three-dimensional vectorial magnetizations. This paper will also discuss the major challenges associated with designing these motors and the possible future research directions in the field.

Discrete sliding mode control method for particle swarm optimization-based brushless DC motor of electric vehicle

Brushless DC motor (BLDCM) is a multivariable nonlinear time-varying system, which is difficult to control. The discrete sliding mode control method for BLDCM of electric vehicle on the basis of particle swarm optimization (PSO) is studied to improve the application of BLDCM in electric vehicle. The mathematical model of BLDCM of electric vehicle is established using the state formula. Based on the mathematical model of BLDCM, through the analysis of electromagnetic torque control of BLDCM, it is clear that controlling the angle between rotor flux and stator flux can accurately control the electromagnetic torque of BLDCM. The adaptive discrete sliding mode controller (SMC) is set to control the electromagnetic torque of BLDCM of electric vehicle, and the PSO algorithm is adopted to obtain the optimal parameters of the adaptive discrete SMC to realize the discrete sliding mode control of BLDCM of electric vehicle. According to experimental results, the proposed method can achieve the accurate control of torque and speed of BLDCM of electric vehicle, and increase the application of BLDCM in electric vehicle.

Method for increasing heat removal effi ciency of a cooling system radiator of an electric motor vehicle of category L

Introduction (problem statement and relevance). At low vehicle driving speeds, when the ram airfl ow is minimal or completely absent, the airfl ow created by the radiator fan is of high importance for the heat removal. In this paper, the airfl ow through the radiator created by the radiator fan was used as a criterion of the heat removal effi ciency, which is calculated from the pressure drop in the radiator for various fan speeds. The possibility of increasing the airfl ow through the radiator by increasing the distance between the fan and the radiator through improvement of the casing design was considered.The purpose of the study is to analyze the infl uence of the radiator casing design on the heat removal effi ciency of the cooling system radiator.Methodology and research methods. The static pressure created at diff erent fan speeds was defi ned at the radiator inlet and outlet in 32 points (16 on each side) using the air pressure probes. The pressure readings were recorded using a 64-channel pressure scanner.Scientifi c novelty and results. The paper deals with research into the infl uence of the distance between the fan and the cooling system radiator surface on the heat removal effi ciency by increasing of the airfl ow through the cooling system radiator. The results of the experiment to determine the optimal distance between the radiator and the fan for various rotational speeds are presented.Practical signifi cance. The value of the distance between the fan and the radiator was determined, which makes it possible to achieve an increase in the airfl ow through the radiator due to more uniform distribution of the airfl ow created by the fan mounted on the radiator casing over the radiator surface

A comparative study of electric motor for low-power density electric vehicles.

Due to the price uncertainty of rare-earth PM materials and limited availability around the globe, it is required to think about new electric motor candidate for automotive industries. According to the literature survey, it is observed that PMBLDC is the widely used in automotive industry for low power applications. There are some noticeable limitations reported with this motor such as high cost of PM, demagnetization, and complex control. Based on the comparative analysis of three motors, i.e., Synchronous Reluctance Motor (SynRM), Permanent Magnet Synchronous Motor (PMSM), and PM-assisted Synchronous Reluctance Motor (PMASynRM) through Finite Element Method (FEM) for the same design parameters, it is concluded the proposed alternative is a PMASynRM. As per the research gap findings, authors have designed the PMASynRM for low-power EV applications with novel rotor geometry. The simulation results of FE analysis validate the proposed motor design for the various performance parameters.

Pengujian konsumsi daya baterai litium-ion pada sepeda motor listrik dengan variasi kemiringan lintasan

The development of electric vehicles in Indonesia, especially the BEV (Battery Electric Vehicle) type, has received serious attention and support from the government. This is evidenced by the issuance of Presidential Regulation Number 55 of 2019 concerning the acceleration of the Battery-Based Electric Motor Vehicle Program for Road Transportation. Electric vehicles designed and developed in this study use an on-wheel BLDC type electric motor, Li-Ion batteries and are equipped with a watt hour meter to monitor battery consumption. The results of testing the accuracy and precision of the watt hour meter show a good value. This is evidenced by the difference in the measurement value of the watt hour meter against the Avometer and the difference between each repetition of the data 5 times which is below 1 Volt and 1 Ampere. Other test results show that the track with a large slope will also experience a large voltage drop, namely 0.8 V at a slope of 100 and the maximum current flowing is 8.35 A. Meanwhile, when the slope of the track is 70 and 60, the battery voltage decreases and the current flowing respectively are 0.5 V and 8.12 A; as well as 0.2 V and 7.84 A.

Modelling and analysis of electromagnetic force, vibration, and noise in permanent magnet synchronous motor for electric vehicles under different working conditions considering current harmonics

AbstractThe vibration and noise of the permanent magnet synchronous motor (PMSM) is mainly caused by its electromagnetic force. Harmonic currents affect the vibration, and noise performance of PMSM by influencing its electromagnetic force. The regularity of electromagnetic force, vibration, and noise characteristics of PMSM for electric vehicles (EVs) under different working conditions influenced by the harmonic currents is studied. Firstly, the analytical model of electromagnetic force under the action of a harmonic current is derived, and the influence of harmonic currents on the electromagnetic force of PMSM is summarised. Secondly, a multi‐physical field coupled vibration, and noise calculation model considering harmonic currents is established using the finite element method, and the vibration, and noise characteristics of PMSM under different operating conditions are analysed. The results show that the harmonic currents have different patterns of influence on the vibration, and noise of the PMSM due to the different advance angles and the saturation degree of the magnetic material under different working conditions. Finally, the validity of the theoretical analysis is verified by experiments, which has academic significance for vibration, and noise reduction of PMSMs for EVs.

Transient Response Characteristics Improvement of Permanent Magnet Synchronous Motor Based on Enhanced Linear Active Disturbance Rejection Sensorless Control

The compactness, cost decrease, and reliability of the auxiliary drive permanent magnet synchronous motors (PMSMs) for battery electric commercial vehicles can be further improved by adopting the position sensorless control technique. The conventional extended back electromotive force (EEMF) based sensorless control algorithm usually requires a phase-locked loop (PLL) and low pass filter to postprocess the estimated rotor position, which deteriorates the transient response of the PMSM significantly. To solve this problem, this article proposes an active disturbance rejection control based EEMF sensorless control method. By designing an extended state observer (ESO) considering the differential term of the position estimation error, timely and accurate estimation of the load disturbance and rotor position can be achieved simultaneously. The adaptive mechanism of the ESO exhibits sound system antidisturbance performance. Moreover, a linear state error feedback controller and feedforward compensation of load disturbance can replace the speed loop PI controller accordingly. Through stability and tracking performance analysis, the proposed method is superior in both steady-state performance and transient-state performance. The proposed scheme is experimentally validated by a 3 kW automotive power steering oil pump motor drive system. The results show that the transient response characteristics are obviously enhanced compared with the conventional methods. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup>

New Method to Coordinate Vibration Energy Regeneration and Dynamic Performance of In-Wheel Motor Electrical Vehicles

A new method including suspension and wheel vibration energy regeneration is proposed in this study to coordinate the contradiction between vibration energy regeneration and dynamic performance of in-wheel motor electric vehicles (IWM-EVs). The influence mechanism of unsprung mass on the dynamic characteristics of IWM-EVs is investigated from the perspective of energy flow, and potential of energy regeneration of IWM-EVs is explored on this basis. A parameter sensitivity analysis of the proposed new method is conducted, and the optimal parameters are determined for a comparative simulation analysis among focus-driven electric vehicles, IWM-EVs, and IWM-EVs with linear electromagnetic dynamic vibration absorber (LEM-DVA). Results show that the proposed new method effectively improves the dynamic performance and achieves coordination between energy regeneration and dynamic performance despite its reduction of the vibration energy regeneration potential of IWM-EVs. A new structure, which integrates a linear electromagnetic damper (LEMD) and a LEM-DVA, is then proposed to implement the coordination method. The equivalent prototype and control system are designed for a hardware-in-the-loop test. The test results show good agreement with that of simulation despite some errors. This finding proves the effectiveness of the new structure in coordinating the vibration energy regeneration and dynamic performance of IWM-EVs.

Risk Assessment of Public Electric Vehicle Battery Swapping Station (SPBKLU)

The use of Electric Vehicles (EVs) in recent years has become an alternative for people to switch to environmentally friendly technology. Exhaust emissions from Internal Combustion Engines (ICE) vehicle which play a big role in air pollution are one of the strong reasons for people to switch. However, one of the main challenges faced when using EVs widely is the limited range and long battery charging times. The existence of limited electric vehicle infrastructure is also an obstacle to the sustainability of the use of EVs for daily activities. Public Electric Vehicle Battery Swapping Station/Stasiun Penukaran Baterai Kendaraan Listrik Umum (SPBKLU) are one of the potential solutions to this problem that allow EV owners to quickly swap out their depleted batteries for fully charged ones. This research study aims to determine the potential risks that can arise in the development process of the Public Electric Vehicle Battery Swapping Station (SPBKLU) as a solution to the limited range and charging time of battery – based electric motor vehicles. The data collection method was carried out through interviews and surveys to 3 respondents from divisions/units who are owners of business processes related to the SPBKLU project. A comprehensive risk assessment through risk management assessment is carried out on the strategic, financial, operational, project and compliance aspects of this technology. The risks that have been identified are then evaluated and prioritized to then be able to make a mitigation plan in reducing the level of risk to reach the level of corporate risk appetite. The results of the risk assessment identified 16 (sixteen) risks with different levels of risk as follows, there is 2 (two) risks at the Extreme level, 3 (three) risks at the Very High level, 9 (nine) risks at the High level, and 2 (two) risks at the Moderate level. Based on the Risk Appetite level of PT PLN (Persero), only 2 (two) risks that are at the Moderate level will be accepted. Meanwhile, for the other 14 (fourteen) risks, a mitigation plan will be carried out to lower the risk level to a Moderate/ Low level. The mitigation plan that will be carried out is prepared in the form of an action plan that the implementation process will be monitored according to the scheduled timeline.

Current Status and Prospects of Electric Motor Applications for Electric Vehicles

Nowadays, with the global pursuit of zero emissions, the trend of automobile electrification is very rapid. The drive motor is the core component of electric vehicles, which has an important impact on the working life and performance of electric vehicles. Therefore, all major manufacturers are trying to find and develop better and more efficient motors. At present, the research on driving motor has become a hot issue in the field of electric vehicles, attracting many scholars to carry out a lot of research work. This paper analyzes four common driving motors in the market, discusses their structure, principle and performance, and lists their advantages and disadvantages for comparison. Then it describes the development status of various types of motors and their applications in electric vehicles, and introduces the prospects of electric vehicle motors and suggestions for improvement of switched reluctance motors.

Adoption of the Synchronous Reluctance Motor in Electric Vehicles: A Focus on the Flux Weakening Capability

This article presents the definition of the performance that the electric motor should have in order to satisfy the requirements of the electric vehicle in terms of acceleration time and maximum speed, starting from a simplified vehicle model, considering the motor torque minimization and the input power minimization. In order to verify the effectiveness of the synchronous reluctance motor in traction applications, it has been evaluated in two case studies: a high-performance vehicle and a city car, where different flux weakening capabilities from the motor in function of the minimization strategies can be pursued to satisfy the requirements. If the car requires high performance in terms of acceleration time and maximum speed, the poor flux weakening capabilities of the synchronous reluctance motor induces a machine oversizing in terms of peak power; by assuming this, it is, however, possible to satisfy the requirements considering the maximum available encumbrance due to an advanced and innovative optimized design procedure. The motor of the city car is obtained only by modifying the stack length and the windings (scaled version), and on this last solution, a prototype has been realized and fully tested; the experimental tests confirm the results of the simulations.

Comparison and Experimental Verification of Different Approaches to Suppress Torque Ripple and Vibrations of Interior Permanent Magnet Synchronous Motor for EV

Interior permanentmagnet (IPM) motors have been the most promising solutions for electric vehicles (EV) drives in terms of torque/power density, compactness, and efficiency. However, IPM motors are vulnerable to large torque ripple and high-level electromagnetic vibrations due to the differences of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d-&amp;q</i> -axis inductance and abundant spectrum of exciting forces. This article presents an intensive comparison of IPM motors with three design approaches to reduce cogging torque, torque ripple, and electromagnetic vibration. The design approaches compared cover skewing slot and segmented rotor approaches commonly used in industry, as well as a new asymmetric pole approach. A commercial 10 kW 8-pole/ 48-slots V-shaped IPM motor for EV traction is taken as the reference base. Extensive performance comparisons, including cogging torque, back-EMF, load current, load torque profiles, PM reliability, and torsional force were carried out. Besides, vibration aspects in terms of exciting force, modal property, and electromagnetic vibration response were also analyzed and compared. Finally, the prototypes with the mentioned three design approaches are produced, respectively, and intensive experimental tests were done to verify the analysis and comparison.

The Oil Spray Cooling System of Automotive Traction Motors: The State of the Art

With growing interest in green technologies and sustainable transport, hybrid and pure electric powertrains are attracting a lot of attention. According to demanded metrics, such as lightweight and high-power density motors, these offer clear motivation to develop advanced thermal management methods and integrate them with conventional cooling approaches. The oil spray cooling method is one of the latest cooling methodologies integrated with the conventional cooling approaches. Therefore, this article provides a comprehensive study on the oil spray cooling approach for electrical motors utilized in electric vehicle (EV) traction application drives. The objective is to provide the reader with a picture of the state of the art regarding the opportunities, challenges, and offered solutions for the cooling requirements in EV motors. In addition, this article presents the guidelines for selecting the appropriate spray nozzles and coolants as well as estimating their performance, spray characteristics, and heat transfer coefficient (HTC) during the design period. Besides, various closed-loop systems of spray cooling approach, including refrigerants as a coolant, low viscosity liquid coolant with high boiling temperature, and high viscosity lubricant oil as a coolant, are discussed with the pros and cons of each system being compared. Moreover, real-life examples of this method, applied in the latest automotive traction motor prototypes, have been described and evaluated. Finally, the performance of different schemes is addressed.

Research on Novel Flat Wire Transposed Winding of PMSM for Electric Vehicle

Permanent magnet synchronous motor (PMSM) for electric vehicles is developing higher frequency and speed but triggering a significant increase of eddy current loss. To resolve the eddy current loss issue, a novel flat wire transposed winding composed of double-row multiple parallel strands is proposed. Transposed winding techniques have been proved to be efficient in reducing eddy current loss by preventing the uneven leakage magnetic field induced by high frequency. The proposed transposition further improved this technique in reducing circulating current loss. Taking a 60-kW PMSM as an example, the novel flat wire transposed winding arrangement is carried out. The 3-D field-circuit coupled finite-element models of 360° complete transposed and incomplete transposed winding PMSM are established, and circulating current losses are compared. The analysis results show that incomplete transposed winding has a better performance in reducing the circulating current loss. The transposition method suitable for novel flat wire transposed winding is obtained, and the feasibility of PMSM with novel flat wire transposed winding to reduce winding losses is proven.

A Three-Phase Nonisolated Pseudo-Six-Phase-Based Integrated Onboard Battery Charger for Electric Vehicles

The trending modern designs of electric vehicle (EV) motors are concerned with maximizing the machine torque density while offering a fault tolerance capability. Among different available stator winding layouts, the so-called pseudo-six-phase (P6P) winding has recently been proposed, which offers an improved torque density and fault tolerance over conventional six-phase distributed winding. An integrated onboard battery charger (IOBC) has also been proposed as a new leading technology that employs the propulsion components of the EV in the charging process to achieve the highest possible charging current with zero machine torque production. In this context, this article proposes a new P6P-based IOBC system. Two different controllers have been investigated, namely, conventional proportional–resonant (PR)-based current control and predictive current control (PCC) techniques. Under the charging mode, the control objectives aim at achieving a balanced three-phase grid current while nullifying machine torque production. To this end, the sequence stator currents are regulated to ensure a balanced <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${xy}$ </tex-math></inline-formula> current, while both the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\alpha \beta }$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${ {0}}^{ {+}}{ {0}}^{ {-}}$ </tex-math></inline-formula> current components are controlled to zero. Furthermore, a novel postfault controller using a PR-based current controller has been proposed, which ensures balanced grid line currents under one open-phase fault. A comparative experimental study has been carried out under different controllers for both vehicle-to-grid (V2G) and grid-to-vehicle (G2V) modes using a 2-hp prototype machine.

Sideband Vibration Suppression of Interior Permanent Magnet Synchronous Motors for Electric Vehicles Under Multiple Operating Conditions

Low-frequency mechanical forces, electromagnetic forces of the medium frequency band, and high-frequency switching frequency current harmonics are three main sources of vibration for electric vehicle (EV) motors under multiple operating conditions (MOCs). These high-frequency vibration sources with large amplitudes are mainly concentrated around the switching frequency and its integral multiples (sideband vibration). The theoretical expression and frequency characteristics for the high-frequency electromagnetic force that produces sideband vibrations were presented in this article, and a new parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\bar {x}$ </tex-math></inline-formula> (the current harmonic amplitude average value) was designed to represent the harmonic level of the current supplied by the inverter in the sideband vibration band. Finite element simulations based on Simplorer-Maxwell-Vibration Harmonic Response and experiments under MOC verified the above theoretically derived characteristic-frequency band of high-frequency electromagnetic forces that generate sideband vibrations. To reduce sideband vibration, an optimized scheme combining active disturbance rejection control (ADRC) and random frequency space vector pulsewidth modulation (RFSVPWM) was proposed to further reduce the parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\bar {x}$ </tex-math></inline-formula> and sideband vibration compared to traditional PI, ADRC, and PI-RFSVPWM. Finally, the feasibility of this scheme for depression sideband vibration was verified by simulations under MOC.

Demagnetization Fault Diagnosis of the Permanent Magnet Motor for Electric Vehicles Based on Temperature Characteristic Quantity

Permanent magnet motors are widely used in the driving system of electric vehicles because of their high power density and small size. However, the permanent magnet motor is prone to demagnetization due to the complex operating environment of electric vehicles and characteristics of permanent magnet motors. To ensure the normal operation of vehicles, the demagnetization fault diagnosis of permanent magnets should develop. In this study, the thermal behavior of a permanent magnet motor under local demagnetization fault is discussed. Results show that the demagnetization of permanent magnets has a significant effect on the temperature of the motor; thus, the temperature is added into input signals of the permanent magnet demagnetization fault diagnosis. The healthy state of the permanent magnet is predicted by the back propagation (BP) neural network to realize the demagnetization fault diagnosis. First, the demagnetization test platform is built to test the performance of the motor, and the current, torque, and temperature of the motor are measured according to different demagnetization degrees. Second, the demagnetization simulation model of the motor is established by the finite-element method, and the air gap magnetic field, loss, and temperature of the motor are analyzed. Lastly, the temperature, current, speed, and torque signals are selected as input signals of the neural network model, and the demagnetization rate of the rotor is taking as the output signal. The neural network prediction model is established and trained, and the good generalization ability is obtained.

Economic and Performance Evaluation of Direct Coupled Motors for Electric Vehicles

Because of constant increase in demand on Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) observed during the last decade, electrical machines manufacturers are confronted with technical and economic constraints, such as cost, weight, torque density, and torque ripple. To satisfy these requirements, this study proposes and applies a method for optimal choosing of competitive motors dedicated to the automotive applications. First a literature review is presented on the electric motors applied to drive systems including Synchronous Reluctance Motors with flux barriers (SynRM), Permanent Magnet Synchronous Motors (PMSM), Induction Motors (IM) and Switched Reluctance Motors (SRM). Subsequently, several candidates of machines that comfortably handle the exigencies of the propulsion system were analysed. Thus, the result of analyses leads to deal with PMSM and SynRM candidate machines regrading to the selected criteria and their numerical electromagnetic models are proposed and simulated using two-dimensional finite element analysis in order to compare their performance under both technical and economic requirements of the road vehicles market. The results of this study indicate that the SynRM is the optimal choice for challenging moderate-cost, high-performance of EVs and HEVs drives.