Maximum Motor Torque Research Articles

Maximum torque per ampere control of permanent magnet/reluctance hybrid rotor dual stator synchronous motor

AbstractCompared with a traditional low‐speed high‐torque permanent magnet synchronous motor (PMSM), a permanent magnet (PM)/reluctance hybrid rotor dual‐stator synchronous motor (PM/RHRDSSM) has the advantages of high torque density and high space utilization. This type of motor is composed of a "back‐to‐back" PM + reluctance hybrid rotor and an inner and outer double stator. The number of poles of the inner and outer unit motors is the same, and the inner and outer stator windings are connected in series, driven by a single inverter. Due to the special mechanical structure and electromagnetic relationship of PM/RHRDSSM, traditional PMSM and synchronous reluctance motor maximum torque per ampere (MTPA) control strategies are no longer applicable. In response to this issue, the authors establishe a PM/RHRDSSM mathematical model of stator winding series structure and propose a MTPA control strategy suitable for this new type of motor. This strategy is aimed at the special mathematical model of PM/RHRDSSM and derives the analytical expression of MTPA trajectory, which minimises the required stator current amplitude of PM/RHRDSSM at various load torques, thereby minimising the motor copper loss. Finally, the effectiveness and practicality of the proposed control strategy were verified through simulation and experiments.

Coordinated torque control for enhanced steering and stability of independently driven mobile robots

PurposeMobile robots with independent wheel control face challenges in steering precision, motion stability and robustness across various wheel and steering system types. This paper aims to propose a coordinated torque distribution control approach that compensates for tracking deviations using the longitudinal moment generated by active steering.Design/methodology/approachBuilding upon a two-degree-of-freedom robot model, an adaptive robust controller is used to compute the total longitudinal moment, while the robot actuator is regulated based on the difference between autonomous steering and the longitudinal moment. An adaptive robust control scheme is developed to achieve accurate and stable generation of the desired total moment value. Furthermore, quadratic programming is used for torque allocation, optimizing maneuverability and tracking precision by considering the robot’s dynamic model, tire load rate and maximum motor torque output.FindingsComparative evaluations with autonomous steering Ackermann speed control and the average torque method validate the superior performance of the proposed control strategy, demonstrating improved tracking accuracy and robot stability under diverse driving conditions.Research limitations/implicationsWhen designing adaptive algorithms, using models with higher degrees of freedom can enhance accuracy. Furthermore, incorporating additional objective functions in moment distribution can be explored to enhance adaptability, particularly in extreme environments.Originality/valueBy combining this method with the path-tracking algorithm, the robot’s structural path-tracking capabilities and ability to navigate a variety of difficult terrains can be optimized and improved.

Field oriented controlled permanent magnet synchronous motor drive for an electric vehicle

<span lang="EN-US">The paper describes field oriented control strategy with space vector pulse width modulation technique of permanent magnet synchronous motor drive system for an electric vehicle. At first, mathematical models of the motor and the drive system for electric vehicle are presented. In order to obtain high performance drive and maximum motor torque, field oriented control strategy and space vector pulse width modulation technique method are applied to drive system in next section. Speed controller design utilizing the popular zero-pole elimination approach causes large integral constant time in case of small rotational damping constant. The desired-transient-response-based approach is employed to overcome the problem. Performance indices include overshoot, undershoot, steady-state speed error, and total harmonic distortion of stator current, are employed to assess the drive systems with two speed controller design methods. Theoretical assumptions are confirmed via simulations and criteria in MATLAB/Simulink environment.</span>

Multimode dual-motor electric vehicle system for eco and dynamic driving

Electric vehicles (EVs) offer benefits in terms of reducing emissions and saving energy over other conventional vehicles. There have been various studies on EVs for energy efficiency and driving performance improvement. As an area of EV systems, dual-motor systems with planetary gear trains have been studied for fuel efficiency improvement, but they have limitations for torque vectoring and maximum torque compared to other typical systems. To overcome these limitations, a novel dual-motor EV system with a planetary gear train has been suggested for eco and dynamic driving modes. The system achieves variable motor operating points for energy efficiency improvement by using dual motors with a planetary gear train. Multiple driving modes are implemented by a synchronizer for torque vectoring and motor maximum torque driving. The suggested system was analyzed by comparison with a typical left-and-right-wheel independent drive dual-motor system with representative EPA test cycles. The novel dual-motor system shows not only the possibility of eco driving by improving fuel efficiency compared to typical dual-motor systems but also performance driving with torque vectoring functionality, which is not available for previous dual-motor systems with planetary gear trains.

Adaptive Stability Control Based on Sliding Model Control for BEVs Driven by In-Wheel Motors

High-speed and complex road conditions make it easy for vehicles to reach limit conditions, increasing the risk of instability. Consequently, there is an urgent need to solve the problem of vehicle stability and safety. In this paper, adaptive stability control is studied in BEVs driven by in-wheel motors. Based on the sliding model algorithm, a joint weighting control of the yaw rate and sideslip angle is carried out, and a weight coefficient is designed using a fuzzy algorithm to realize adaptive direct yaw moment control. Next, optimal torque distribution is designed with the minimum sum of four tire load rates as the optimization objective. Then, combined with the road adhesion coefficient and the maximum motor torque constraint, the torque distribution problem is transformed into a functionally optimal solution problem with constraints. The simulation results show that the direct yaw moment controller based on the adaptive sliding mode algorithm has a good control effect on the yaw rate and sideslip angle, and it can effectively improve vehicle adaptive stability control. In the optimal torque distributor based on road surface recognition, the estimated error of road adhesion is within 10%, and has a greater margin to deal with vehicle instability, which can effectively improve vehicle adaptive stability control.

An adaptive receding horizon-based flexible mode switching control strategy of parallel hybrid electric vehicles

Mode switching is crucial to efficient drive in variable driving conditions for hybrid electric vehicles (HEVs), thus many scholars are attracted to implement its high-quality control. The receding horizon control method is an attractive method to solve this problem. However, the choice of prediction horizon is arduous due to the contradiction between the optimization performance and the computational cost. Motivated by this issue, this paper proposes an adaptive receding horizon control (RHC) method, which contains optimization layer (OPL) and feedback control layer (FCL). First, an OPL adaptive receding horizon control method is proposed to obtain the optimal control command, in which a novel adaptive factor, considering the proportional between the maximum traction motor torque and powertrain demand torque, is proposed to adjust the prediction horizon length and control constraints. Then, regarding OPL output as the reference trajectory, a lower-RHC method is designed in FCL to track the reference trajectory. Finally, the proposed control method is validated in simulation and bench experiment. Compared with the existing method, the clutch trajectory is optimized by RHC with adaptive prediction horizon and constrains, and the anti-disturbance ability is enhanced by the lower-RHC. The simulation and bench experiment results indicate that the 0–40 km/h acceleration time and jerk are reduced using the proposed method, respectively.

Design and Testing of an End-Effector for Tomato Picking

Based on the structural shortage of an agricultural labor force and the continuous increase in tomato planting scale in China, as well as the limitation of a greenhouse working environment on the development of tomato picking productivity, a motor-driven end-effector for a tomato picking robot based on a hybrid force/position control strategy was designed. First, a hybrid force/position control strategy was applied to control the picking process. Consistent with this strategy, the mechanical structure design of the end-effector was determined. The maximum torque of the finger joint motor was verified by applying a load to the end-effector fingertip under a parabolic linear angular velocity. Second, the D-H method was used to establish the end-effector single-finger and whole-hand coordinate systems and to perform forward and inverse kinematic analysis. The Monte Carlo method was used to analyze the workspace of the end-effector, and an isochronous interpolation algorithm was used to analyze the angular displacement of the motor. A basic algorithm for starting, stopping and accelerating the finger joints was designed to achieve the smooth movement of the end-effector. The control system for the end-effector was designed based on STM32F103ZET6, and the end-effector remote wireless debugging system was designed based on Tiny6410. Finally, a test prototype of the tomato picking end-effector was manufactured and picking tests were conducted, which showed that our tomato picking end-effector moved smoothly. The proposed control algorithm reduced the impact force and recorded the contact force between the end-effector and the tomato in real time, and the end-effector essentially achieved nondestructive picking. Therefore, our tomato picking end-effector demonstrated good utility in practice.

A study of the dependence of the 3-phase cage motor maximum torque on the centroid of the rotor bar section

A study of the dependence of the 3-phase cage motor maximum torque on the centroid of the rotor bar section

A study of the dependence of the 3-phase cage motor maximum torque on the centroid of the rotor bar section

The paper investigates the relative influence of the centroid of the three-phase squirrel cage induction motor rotor bar cross section, on the breakdown (maximum) torque of the machine. The influence of the angle of taper, the top width and the radial depth of the bar section, as established design variables, were also investigated so as to properly situate the degree of influence of the centroid, in comparison; as far as the maximum torque is concerned. The machines were investigated in their steady state operating mode using the equivalent circuit method. The machine learning capabilities of the Least Square Support Vector Machine (LSSVM) was deployed to extract by prediction, information about the likely dependencies between the randomized block of the geometric variables and the maximum torque, and the captured information was stored using the Root Mean Square Error (RMSE) of predictions. The validated results show that the rotor leakage reactance – a part determinant of the maximum torque; tends to show some significant sensitivity to a design change in the centroid of the transverse section of the rotor bar.

Study of the parameters for a parallel hybrid electric vehicle

At present, the expansion in vehicle population has contributed to the increase in carbon emissions and has led to an even greater increase in the need for fuel. In this way, the hybrid vehicle (HEV) and the electric vehicle (EV) are being introduced to reduce fuel consumption and exhaust gas emission instead of conventional vehicles. The study of parameters for the hybrid electric vehicle is important to design the powertrain of the vehicle. The parameters of hybrid vehicles consist of the rate of internal combustion engine (ICE) power, transmission gear ratios, motor maximum torque and power, capacity and power of battery. The vehicle model with the regenerative model is built to calculate the regenerative energy for driving on a road condition. The design purposes to match the vehicle with the specified performances, like as speed and acceleration. Many parameters are chosen from analysis of this results. And then, as a result, fuel consumption of test vehicle model reduces 15% than the conventional vehicle in this study.

Floating Microdisks Rotated by Molecular Motors

AbstractA possibility of utilization of molecular motors for creation of unidirectional rotation of tiny disks floating on a surface is considered theoretically. The bottom side of the disk is covered with grafted motors combined with flat blades submerges into a viscous liquid for torque generation. When exposes to UV‐light, the motors start to rotate all in the same direction, and they transfer their rotation to the blades creating a mechanical torque that turns the disk. The disk angular velocity scales as ω ∼ Ω L/R where Ω is motor angular velocity, L is the length of the oars, R is the micro‐disk size. A competition between directional ballistic‐type rotation and rotative diffusion is considered. The setup can be used for evaluation of the primary motor parameters: the motor rotation speed Ω = 2πf, and the maximum motor torque load Mmax.

Co-Simulation-Based Verification of Torsional Vibration Protection of Electric-Driven Railway Vehicle Wheelsets

Torsional vibration is an oscillation phenomenon occurring at driven railway vehicle wheelsets. As the resulting dynamic stresses can be significantly larger than the maximum static motor torque, axle and press fit are at risk of failure. To prevent dangerous vibration events and with these, press fit and axle from failure, traction drive manufactures nowadays used to implement vibration suppression algorithms in drive controls. In this paper, the effectiveness of such suppression algorithms is analyzed. Furthermore, as a pilot survey, we analyze to what extend traction controls influence the excitation of torsional vibration.

Design of electronic cam for lower hook mechanism of fishing net-weaving machine based on polynomial fitting

The working efficiency and stability of the double hook-based fishing net-weaving machine is mainly determined by the lower hook mechanism. In this work, a new kind of lower hook mechanism, which is driven by four servo motors, is presented, and the electronic cam curve of the lower hook mechanism is introduced. First, cubic B-spline interpolation is used to get the basic motion path of the lower hook plate, and then the piecewise quintic polynomial fitting method is used to fit the motion path. Finally, self-adaptive mutation-based particle swarm optimization is put forward and used to obtain the optimal parameters of the quintic polynomial, which performs better compared with the other two particle swarm optimization algorithms in this study. Experiments suggest that the electronic cam curve generated by the piecewise quintic polynomial fitting has got 55.91% (horizontal motors) and 60.96% (vertical motors) optimization in maximum motor torque compared with curves generated by cubic B-spline interpolations. In addition, the new lower hook mechanism and its moving curve described in this paper improved the theoretical weaving speed of the fishing net-weaving machine, providing a basis for digital improvement of the knotted net-weaving industry.

Assessment of the Energy Consumption and Drivability Performance of an IPMSM-Driven Electric Vehicle Using Different Buried Magnet Arrangements

This study investigates the influence of the buried magnet arrangement on the efficiency and drivability performance provided by an on-board interior permanent magnet synchronous machine for a four-wheel-drive electric car with two single-speed on-board powertrains. The relevant motor characteristics, including flux-linkage, inductance, electromagnetic torque, iron loss, total loss, and efficiency, are analyzed for a set of six permanent magnet configurations suitable for the specific machine, which is controlled through maximum-torque-per-ampere and maximum-torque-per-voltage strategies. Moreover, the impact of each magnet arrangement is analyzed in connection with the energy consumption along four driving cycles, as well as the longitudinal acceleration and gradeability performance of the considered vehicle. The simulation results identify the most promising rotor solutions, and show that: (i) the appropriate selection of the rotor configuration is especially important for the driving cycles with substantial high-speed sections; (ii) the magnet arrangement has a major impact on the maximum motor torque below the base speed, and thus on the longitudinal acceleration and gradeability performance; and (iii) the configurations that excel in energy efficiency are among the worst in terms of drivability, and vice versa, i.e., at the vehicle level, the rotor arrangement selection is a trade-off between energy efficiency and longitudinal vehicle dynamics.

Sustainable operation analysis of the mining industry power supply system

The paper presents an analysis of operating currents and torques during self-starting of motors with a voltage of 6 kV for cases of short circuit in the head feeders from the main step-down substation and in the feeders to the most distant substations of mining enterprises. For the network under consideration, the characteristic modes are: short circuit on the buses of shop substations. For the mining industry when selfstarting asynchronous motors with a squirrel-cage rotor and synchronous motors with asynchronous startup, the current multiplicity will be determined by the duration of the power failure (run-down duration). It has been established that the acceleration of motors during self-start will be somewhat slower than the usual start, since self-start begins at a speed of 0.89–0.94 of the synchronous speed and a resistance torque is equal to 0.65–0.75 of the maximum motor torque. The self-starting time of the motors is from 9 s to 42 s. To ensure self-starting conditions in the most severe modes in mountain conditions, it is necessary to make changes to the protection settings presented in the work.

Morphological and tribological studies of thermal plasma jet deposited coatings used in cardan joints

All wheels drive (AWD) and railway vehicles require a longitudinal transmission. Double cardan joint is one of the most employed transmission, as it allows misalignments between the shafts. This transmission must support the maximum motor torque and high dynamic loads. In such situation, from tribological viewpoint, cardan joints are subjected to abrasive wear. To increase wear resistance of cardan joints, its rolling elements can be coated with ceramic or metal-ceramic coatings. This paper presents an experimental research on microstructure and dry friction characteristics of two steel samples obtained from cardan crosses (40Cr10 and RUL2), coated by two types of metallic powders (METCO32 and METCO72). Microstructural studies of both surface and cross –section of samples were performed using scanning electron microscopy (SEM). Dry tribological tests at constant speed and load were carried out on AMSLER machine. The micro-structural experiments revealed a structure with a relatively homogeneous character, partially melted particles and several microcracks being detected. Following the tribological tests, it was found that the METCO72 coating provides the lowest coefficient of friction, near values being obtained for both substrates of 40Cr10 and RUL2. The best combination is formed by 40Cr10 substrate and METCO72 coating.

Optimization of Permanent-Magnet Spherical Motor Based on Taguchi Method

The finite-element model is established to simulate electromagnetic forces of a permanent-magnet (PM) spherical motor using the commercial software from Ansoft. The Taguchi method is used to optimize the magnetic field density in the radial air gap and the maximum torque of the PM spherical motor. The final optimization parameters are determined by a response surface method (RSM). The simulation results of the optimized motor are compared with those of the original motor to show that the output performances of the optimized motor have improved greatly, which verifies the effectiveness and practicability of the Taguchi method on the optimization of the PM spherical motor.

TORQUE DETERMINATION OF A FACE MAGNETIC COUPLING AT THE ENGINEERING DESIGN STAGE

In article the determination possibility of the transferring torsional moment of the face magnetic coupling with highly coercive permanent magnets is considered. The received mathematical expression allows at a stage of the engineering design to define the transferring torsional moment of the face magnetic coupling depending on the asynchronous electric motor maximum torque data given by the directory on electric motors, and to calculate a phase shift angle of semicouplings taking into account their inertia moments, driven and slave rotating masses of machine, the operating torques of the electric motor, magnetic coupling and the machine itself on the stages of documentation development work.

Optimization of maximum torque output in the wide speed range of a PMSM traction control system

This paper introduces a permanent magnet synchronous motor maximum torque control method for the wide speed range of a traction control system. This method tracks the maximum torque per ampere operating point and generates a d-axis current command according to the injection of a high-frequency angle signal to the current. This method is parameter independent when looking for the maximum torque per ampere operating point. By not injecting any real signal to a permanent magnet synchronous motor, this method does not increase the amount of copper and iron losses resulting from real signal injection. To obtain a maximum torque output in a wide speed range, this method considers the maximum amplitude limits of voltage and current when the traction motor runs in a flux weakening control field. This method is also robust to current and voltage harmonics, speed mutations, and torque disturbances. Experiment and analysis are conducted on a permanent magnet synchronous motor traction control system prototype under various operating conditions to verify the effectiveness of this method.

Maximum Torque Analysis and Extension in Six-Step Mode-Combined Field-Weakening Control for Induction Motor Drives

This paper presents a six-step mode-combined field-weakening control scheme to improve the maximum output torque of induction motor (IM) in the voltage-extension region. Compared with the conventional inscribed circle and hexagon methods, the proposed six-step mode method can increase the utilization of dc-link voltage, leading to extended maximum output torque capability. However, the six-step mode operation will inevitably result in torque ripple and current harmonic. To figure out the quantitative relation between the torque extension and ripple, an “equivalent-circuit”-based method is proposed for theoretical torque analysis in six-step mode. To cut off the main current harmonic (sixth harmonic), a second-order generalized integrator based band-stop filter is designed for the feedback current in the current loop. The designed filter can achieve IM stable operation in a six-step mode without affecting the bandwidth of the current loop. The experimental results from a 3.7-kW IM setup verify the effectiveness of the proposed scheme.