Magnet Synchronous Motor Research Articles

Research on Permanent Magnet Linear Motor without Friction Feed

In order to eliminate the friction of the feed system in NC Machine Tools, this paper presented a novel direct magnetic levitation permanent magnet linear motor. First, the structure and magnetic levitation theory of the direct magnetic levitation motor were discussed. Second, on the basis of the motor magnetic hierarchical model, the expression of the magnetic field and the electromagnetic force was derived by the virtual displacement method. Finally, no-load magnetic field, load air-gap flux density and the electromagnetic force of the motor were simulated by using Ansoft Maxwell 2D software. The results of simulation test indicated that using direct magnetic levitation permanent magnet linear synchronous motor can realize the friction-free feed of NC Machine Tools.

Design of a High Performance IMP Motor for Machine Tool Applications

This paper presents a 3-phase, 7 kW, 3900 rpm, 4-pole, 12-slot interior permanent magnet (IPM) synchronous motor for machine tool applications. To reduce the torque pulsations of the initial designed motor, three small circular holes are drilled in the magnetic island, and the Taguchi parameter method coupled with the finite element method (FEM) analysis is employed to minimize the level of cogging torque, torque ripple and magnet volume of the motor. Results from the optimized motor demonstrate that the motor is favorable regarding cogging torque minimization, torque ripple minimization and magnet volume minimization

Study of EV Motor Control Scheme

According to electrical vehicle (EV) working requirements, a built-in permanent magnet (IPM) synchronous motor is selected as the topic motor. A mathematical model about the motor is described here. To make the EV run smoothly, safely and economically, two control loops for the electric motor are developed. One is based on motor current control, which consists of maximum torque per ampere control and field weakening control. Other is motor speed control loop, in which a sliding mode control (called a variable speed exponential reaching law) is used. Through simulation study, the control scheme developed here can make the motor work well, which means it can be used in some EV driving systems.

Experiment Platform Design cSPACE-Based for a Permanent Magnet Linear Synchronous Motor Driven Inverted Pendulum

Permanent magnet linear synchronous motor (PMLSM) driven inverted pendulum is a new member of present similar devices, various unexpected disturbances such as lag effect of a belt attached to a cart and errors caused by a rotary encoder while detecting the position of a cart can be eliminated or reduced to a small range.In this paper, ironless permanent magnet synchronous linear motor driven inverted pendulum experiment platform is developed. The plant is hardware in the loop real time simulation control development system (Hardware-in-Loop, HIL)based on TMS320F2812DSP and MATLAB, it can use simple and efficient way to achieve linear motor driven inverted pendulum real-time control. Long design time for programming and debugging difficulty are avoided for traditional programming language. Control algorithm can be investigated directly on MATLAB/Simulink, and can be generated automatically control code to control single and double -stage inverted pendulum system. The real performance of the driven inverted pendulum is researched in this paper, the results showed that the controllability of the driven inverted pendulum is fine.

Fault-Tolerant Permanent Magnet Synchronous Linear Motor

The principle and characteristics of Fault-tolerant Permanent Magnet Synchronous Linear Motor are introduced. The design or computational method of the polar distance of concentrated winding coil, the armature parameters, the armature winding parameters, the coil diameter, the distance from the adjacent armature windings are given. The magnetic thrust equation is derived, and the core issues are analyzed. It provided theoretical basis for structural optimization of the Fault-tolerant Permanent Magnet Synchronous Linear Motor.

Electromechanical system with IPM motor used in electric or hybrid vehicle

PurposeIn the last few years, the understanding of environmental problems has grown. Car producers – original equipment manufacturers – are aiming to reduce fuel consumption and pollution. In order to fulfil these aims, new technologies have been launched. Many hydraulics systems have been removed and replaced with electric ones, e.g. power steering, water and oil pump, etc. In this paper, an electromechanical subsystem used in an automotive application is analyzed. The subsystem is composed of interior permanent synchronous magnet motor and electronic control unit. The range of mechanical output power for studied system is up to 1 kW. The aim of this paper is to compare electromechanical systems working with different on‐board voltage levels in order to find the optimum balance between motors' and electronics' efficiency. This will help to decrease the total system's weight, the consequence of which will decrease fuel consumption and reduce CO2 emissions.Design/methodology/approachDuring the analysis, the reduced order modelling (ROM) techniques has been applied. First, with utilization of finite‐elemente‐methode the basic motor's parameter like: synchronous inductance and flux per pole as a function of the direct‐axis current and also the quadrature‐axis current are calculated. In the second step, these parameters are used in the system simulation. During this simulation, the maximum torque per ampere control strategy together with ROM techniques was used.FindingsAs a result, the performance of the system for different voltage levels has been obtained. Additionally, the important factors for an electromechanical system, such as maximum power density, sizing and cost of the total electromechanical system, have been compared.Practical implicationsThe performed comparison shows that the cost optimized system should work with the higher voltage, where the electric motor size is reduced ca. 25 per cent. This result is also valid for different electromechanical systems in an automotive area, e.g. automated manual transmission, engine cooling and electric compressor.Originality/valueIt is the first paper, where electric power steering system design for different on‐board voltage levels has been systematically analyzed and compared. Results from this paper can be also applied to different electromechanical systems mounted in hybrid or electric cars.

A comparative study on the spindle system equipped with synchronous and induction servo motors for heavy duty milling with highly stable torque control

In order to create a higher torque spindle system for productive milling operations, rotational speed stability against the torque disturbance has been studied with respect to the spindle mechanical design parameters, actuator types and spindle control algorithms. The study showed a remarkable difference in the spindle rotational speed stability against torque disturbance between a spindle system equipped with an induction servo motor and a permanent magnet synchronous servo motor. The results of this study have been obtained by theoretical analysis, numerical simulation and physical experiments, and the experimental study showed that the hybrid actuation spindle achieves longer tool life.

A Comparative Study of Two Permanent Magnet Motors Structures with Interior and Exterior Rotor

Currently, the permanent magnet motors PMM represent an attractive solution in the electric traction field, thanks to their higher performances than other electric motors. In this context, this work represents an analytical study and validation by the finite element method of two configurations, the radial flux permanent magnet syn chronous motors with exterior rotor PMSMER and with interior rotor PMSMIR. This paper is divided into two sections: In the first section, we represent the analytical study based on electromagnetic law of the two structures PMSMER and PMSMIR. In the second section, we represent a comparative study of the two structure performances.

Equivalent Hardware Representation of PM Synchronous Motors From the Physics-Based Phase Variable Model Obtained Through FE Computation

This paper presents an approach utilizing a machine model to achieve an equivalent hardware representation of machines as a computational prototyping tool. The purpose of our study is to find a way to perform hardware experiments of machine control without the actual machine. The proposed approach provides a way to test the control before the machine is fabricated, or in the cases where the controller needs to be experimentally tested before being implemented onto the actual machine. The equivalent hardware of a machine is built using a current controllable load, a controller, and a machine model in a hardware-in-the-loop (HIL) real time simulation environment. The equivalent hardware representation of the machine is achieved by controlling the currents of the controllable load to be the same as the currents of the actual machine under the same operating conditions. The machine model is used to provide the reference signal for the control. In this paper, the introduction of the proposed approach is presented focusing on three issues: the machine model, the procedure to enable the machine model to be compatible with the HIL real time simulation, and performance examination. Finally, the validity of the proposed approach is demonstrated with the voltage and current waveforms and the torque and speed profiles measured at the developed equivalent hardware of the machine. A 2-hp surface mounted permanent magnet (PM) synchronous motor is used as an example machine to present and verify our work.

Sensorless Direct Torque and Flux Controlled Interior Permanent Magnet Synchronous Motor Drive Incorporating Field Weakening

This paper presents a sensorless space vector modulation (SVM) direct torque and flux control (DTFC) scheme for interior permanent magnet (IPM) synchronous motors. Closed-loop control of both the torque and stator flux linkage is achieved via two proportional-integral (PI) controllers. The reference voltage vectors are generated by a SVM unit, which replaces the switching table in the conventional direct torque control (DTC) scheme. For sensorless operation, a speed observer based on the stator flux linkage is investigated in this paper. The speed estimator is simple, software-based and irrespective to machine parameters. Hence, the basic advantages of a DTC controller are retained. The operating range of the DTFC drive is extended into the high speed region by incorporating flux weakening. Experimental results confirm the effectiveness of the sensorless DTFC scheme.

An At-All Operating Points Highly Efficient PMSM for HEV

Average losses of the electric drive throughout a driving cycle are an important issue for hybrid electric vehicles. Permanent magnet synchronous electric motors (PMSM) are the most efficient electric drives under load conditions. However, they suffer from idle losses at high speed and low load, which is a typical operating condition in highway cycles. This leads, in some cases, to even higher fuel consumption of HEV vs. conventional vehicles.As well designed permanent magnet machines for HEV usually have excellent efficiency at operating points close to their rating, the main focus of the presented work is achieving an improvement in no load and reduced load conditions. Such losses will occur at high speed and low load, because the PMSM creates an induced voltage exceeding the battery voltage, which must be compensated by an inductive voltage drop through the motor inductance by a purely reactive current causing losses.A proposal for a special design for PMSM with regard to the ability of active reduction of those losses at high speeds is made in the following comment: The compensation current depends on the motor inductance. Obviously, a high inductance in the axis of magnetization needs a low compensation current, whereas a low inductance in the quadrature-axis results in a large constant power range. So a special design of an asymmetrical PMSM has been developed in order to achieve minimum idle losses.

Radical basis functional network-based cogging force estimator of permanent magnetic liner synchronous motor with q<1 structure

The cogging force is of great impact to the efficiency of permanent magnetic liner synchronous motor(PMLSM) especially in high precision and low speed. According to the fractional slot with q1 structure of PMLSM, FEM is used to analyze the influence of cogging force. Supposed estimator based on radical basis functional network(RBFN) is presented by improved algorithm. To select the right spread factor of base function, the accelerate fuzzy C-means(AFCM) is used in data clustering. Then, OLSA is used to choose the center vector from the clustering center. Comparing to the estimator based on back propagation neural network(BPNN) with momentum method, the novel estimator increases the clustering of neural network with boosting learning rate. Results show the fractional slot with q 1 structure effectively reduces the influence of cogging force in PMLSM. Through the estimator based on RBFN, the parameters of the PMLSM can be evaluated in the design period. By satisfying the standards of cogging force ripple, the estimator achieves the agility demand and improves the design level of PMLSM.

Innovative Lightweight Technologies Using Power Electronics on Shinkansen High-Speed Electric Multiple Units

In 1964, Japan's Tokaido Shinkansen (bullet train) line was the world's first commercial-service, high-speed railway operating at more than 200 km/h. Since then, the Tokaido Shinkansen has demonstrated itself as a successful business and technological advancement. Historically, the Japanese high-speed train system, the Shinkansen, has employed a power-distributed system, an electric multiple-unit (EMU) system, with many advantages such as low axle load and good traction and braking performance. High-speed EMUs take advantage of technological innovations such as electronic technology. An innovative alternating current (AC) drive system, comprising a power converter with a gate turn-off thyristor and AC asynchronous motors, brought a high-performance and lightweight traction system to high-speed EMUs in the 1990s. In EMUs, traction system equipment can be distributed over a train set, and tractive axles throughout the train set can obtain required tractive force without putting a heavy load on the axle. Thus, maximum axle load is reduced, and a lightweight, high-performance train results. Furthermore, recent innovations, such as low switching loss power devices and high-power permanent magnets, have improved AC drive systems of high-speed EMUs of the 21st century. Features and advantages of high-speed EMU systems on the Shinkansen are described, as are recent technological innovations that have given birth to lightweight traction systems, such as the permanent magnet synchronous traction motor and power converters with train–draft-cooling systems. Environmentally friendly aspects of these innovative EMUs are introduced as well.

DEVELOPMENT, IMPLEMENTATION AND PERFORMANCE ANALYSIS OF INTELLIGENT CONTROLLERS FOR IPM SYNCHRONOUS MOTOR DRIVE SYSTEMS

This paper provides a design, implementation, and performance investigation of different intelligent controllers, particularly, fuzzy logic controller (FLC), artificial neural network (ANN), and neuro-fuzzy (NF) controllers for interior permanent magnet (IPM) synchronous motor (IPMSM) drive systems. A specific FLC is designed for the IPMSM drive based on motor dynamics and nonlinear load characteristics. A radial basis function network (RBFN) is utilized as an ANN. For NF control a fuzzy basis function network (FBFN) is developed in which the fuzzy logic concepts are embedded. In order to provide a demonstrative evidence of comparison, a closed loop vector control scheme for IPMSM incorporating intelligent controllers is successfully implemented in real-time using a digital signal processor (DSP) board DS1102. The performance of various intelligent controllers are investigated and compared both in simulation and experiment. A review of intelligent controller applications for motor drive systems is also presented in this paper. This paper intends to provide useful information for researchers and practicing engineers regarding intelligent controller applications in IPM motor drives.

Robust position control of a perturbed electrical servo drive system via the adaptive fuzzy sliding-mode technique

A novel adaptive fuzzy sliding-mode control (AFSMC) system for high-precision position control of a perturbed electrical servo drive is developed in this paper. The proposed AFSMC system is designed via the approximation ability of a fuzzy system to mimic the good behaviour of a total sliding-mode control (TSMC) system, which is designed without the reaching phase of a conventional sliding-mode control (SMC). In the developed system, a priori knowledge of the system information is not required. Moreover, the gradually increasing estimate upper bound, which may induce the control effort into saturation and excite unstable system dynamics in some conditions, would not exist. In the proposed controller, the adaptive tuning algorithms are developed in the sense of the Lyapunov stability theorem, so that system-tracking stability can be guaranteed. Finally, the effectiveness of the proposed control scheme is verified via the experimental results of a field-oriented control permanent magnet (PM) synchronous motor.

Feasibility of a Group Drive with Two Permanent Magnet Synchronous Traction Motors for Commuter Trains

Gearless permanent magnet synchronous traction motors (PMSM) offer lower life cycle costs compared to induction motors with gear units; however, PMSM usually require one inverter per motor. In commuter trains, one inverter feeds up to four induction motors – a cost advantage for induction motor drives. The feasibility of a group drive with two PMSM fed by one inverter is investigated to limit the number of inverters.

A simple hybrid fuzzy PD controller

In many practical applications, the performance of a controlled system highly depends on whether a high quality differential signal can be obtained based on the non-continuous measured position signal only. In this paper, a simple hybrid fuzzy PD (proportional and derivative) controller is developed, by combining two nonlinear tracking differentiators to a conventional fuzzy PD controller. The main improvement of the proposed simple hybrid fuzzy PD controller is that it has high robustness against noise and easy for engineering implementation. Simulation and experimental comparison studies on motion control of a permanent magnet synchronous AC motor validate the effectiveness and efficiency of the proposed controller.

A sensorless initial rotor position estimation scheme for a direct torque controlled interior permanent magnet synchronous motor drive

In direct torque control (DTC) scheme, the requirement of the continuous rotor position sensor and coordinate transformation is eliminated since all the calculation is done in stator reference frame. However, the DTC scheme requires the position sensor to determine the initial position of the rotor at starting. Elimination of the shaft-mounted position encoder is a very desirable objective in many applications since this sensor is often one of the most expensive and fragile components in the entire drive system. This paper presents a sensorless method of determining the initial rotor position of a direct torque controlled interior permanent magnet (IPM) synchronous motor drive. The method consists of injecting a high frequency voltage to the windings and examining the effects of the saliency on the amplitude of the corresponding stator current components. This method does not depend on the level of static load and on any motor parameters. The magnet polarity of the rotor at its initial position is also identified using the effect of saliency. Modeling and experimental results verify the effectiveness of the proposed method.

An MRAC-based nonlinear speed control of an interior PM synchronous motor with improved maximum torque operation

A model reference adaptive control (MRAC)-based nonlinear speed control strategy of an interior permanent magnet (IPM) synchronous motor with an improved maximum torque operation is presented. In most servo systems, the controller is designed under the assumption that the electrical dynamics are neglected by the field-oriented control. This requires a high-performance inner-loop current control strategy. However, the separate designs for a high-performance current regulator and a robust speed controller need considerable effort. To overcome this limitation, an MRAC-based nonlinear speed control strategy for the IPM synchronous motor is presented, considering the whole nonlinear dynamics. Nonlinear speed control is achieved by an input–output linearization scheme. This scheme, however, gives an unsatisfactory performance under the mismatch of the system parameters and load conditions. For the robust output response, the controller parameters are estimated by an MRAC technique in which the disturbance torque and flux linkage are estimated. The adaptation laws are derived from Lyapunov stability theory. In view of the drive efficiency, the motor has to provide the maximum torque for a given input. To drive the IPM synchronous motor under improved maximum torque operation, the estimated flux linkage is employed for the generation of the d-axis current command. The robustness and output performance of the proposed control scheme are verified through simulation results.

Design and performance comparison of a stationary frame digital current control for a PM synchronous motor

An improved stationary frame-based digital current control technique for a permanent magnet (PM) synchronous motor is considered. The stationary frame current controller is known to have the advantage of simple implementation. However, there are some unavoidable limitations such as a steady-state error and a phase delay in the steady-state when using the proportional-integral (PI) controller. This control performance can be greatly improved by employing the exact decoupling control inputs for the back EMF, resulting in an ideal steady-state control characteristic irrespective of the operating condition, as in the synchronous PI decoupling controller. However, its steady-state response may be degraded by the inexact cancellation inputs due to the variation in the parameter. To improve the control performance in the stationary reference frame, the disturbance is estimated using a modified time-delay control. The proposed control scheme is implemented on a PM synchronous motor using DSP TMS320C31. The simulations and experiments verify that an improved control performance can be obtained in the stationary reference frame.