Disturbances rejection optimization based on improved two-degree-of-freedom LADRC for permanent magnet synchronous motor systems

Permanent magnet synchronous motor(PMSM)speed control systems with conventional linear active disturbance rejection control(CLADRC)strategy encounter issues regarding the coupling between dynamic response and disturbance suppression and have poor performance in suppressing complex nonlinear disturbances.In order to address these issues,this paper proposes an improved two-degree-of-freedom LADRC(TDOF-LADRC)strategy,which can enhance the disturbance rejection performance of the system while decoupling entirely the system's dynamic and anti-disturbance performance to boost the system robustness and simplify controller parameter tuning.PMSM models that consider total disturbances are developed to design the TDOF-LADRC speed controller accurately.Moreover,to evaluate the control performance of the TDOF-LADRC strategy,its stability is proven,and the influence of each controller parameter on the system control performance is analyzed.Based on it,a comparison is made between the disturbance observation ability and anti-disturbance performance of TDOF-LADRC and CLADRC to prove the superiority of TDOF-LADRC in rejecting disturbances.Finally,experiments are performed on a 750 W PMSM experimental platform,and the results demonstrate that the proposed TDOF-LADRC exhibits the properties of two degrees of freedom and improves the disturbance rejection performance of the PMSM system.

Improved Particle Swarm Optimization for Parameter Identification of Permanent Magnet Synchronous Motor

In the process of identifying parameters for a permanent magnet synchronous motor,the particle swarm optimization method is prone to being stuck in local optima in the later stages of iteration,resulting in low parameter accuracy.This work proposes a fuzzy particle swarm optimization approach based on the transformation function and the filled function.This approach addresses the topic of particle swarmoptimization in parameter identification from two perspectives.Firstly,the algorithm uses a transformation function to change the form of the fitness function without changing the position of the extreme point of the fitness function,making the extreme point of the fitness function more prominent and improving the algorithm’s search ability while reducing the algorithm’s computational burden.Secondly,on the basis of themulti-loop fuzzy control systembased onmultiplemembership functions,it is merged with the filled function to improve the algorithm’s capacity to skip out of the local optimal solution.This approach can be used to identify the parameters of permanent magnet synchronous motors by sampling only the stator current,voltage,and speed data.The simulation results show that the method can effectively identify the electrical parameters of a permanent magnet synchronous motor,and it has superior global convergence performance and robustness.

Review of Field Weakening Control Strategies of Permanent Magnet Synchronous Motors

Due to high power density,high efficiency,and accurate control performance,permanent magnet synchronous motors(PMSMs)have been widely adopted in equipment manufacturing and energy transformation fields.To expand the speed range under finite DC-bus voltage,extensive research on field weakening(FW)control strategies has been conducted.This paper summarizes the major FW control strategies of PMSMs,which are categorized into calculation-based methods,voltage closed-loop control methods,and model predictive control related methods.The existing strategies are analyzed and compared according to performance,robustness,and execution difficulty,which can facilitate the implementation of FW control.

Fault-Tolerant Operation of Five-Phase Permanent Magnet Synchronous Motor with Independent Phase Driving Control

The multi-phase motor drive system with multiple H-bridge power supply has high fault tolerance,which is widely used in aerospace,electric vehicle,ship integrated power system and other fields.In this paper,a fault-tolerant control strategy based on decoupling control and stator current compensation is proposed for the propulsion system of five-phase PMSM with independent neutrals.Firstly,the mathematical model of PMSM is established by using vector space decoupling method;Secondly,a stator current compensation method is adopted to carry out fault-tolerant control after the motor has single-phase and two-phase open-circuit faults and the fault-tolerant control system based on decoupling control is established;Finally,the decoupling control model and the fault-tolerant control of stator current compensation are verified by the simulation and experiment.The simulation and experiment results show that the method can reduce the torque ripple caused by the stator winding open-circuit fault,and the operation performance of the motor under fault condition is significantly improved.

Speed sensorless FCS-MPTC based on FOSM-MRAS five-phase permanent magnet synchronous motor

For the two-level five-phase permanent magnet synchronous motor(FP-PMSM)drive system,an improved finite-control-set model predictive torque control(MPTC)strategy is adopted to reduce torque ripple and improve the control performance of the system.The mathematical model of model reference adaptive system(MRAS)of FP-PMSM is derived and a method based on fractional order sliding mode(FOSM)is proposed to construct the model reference adaptive system(FOSMMRAS)to improve the motor speed estimation accuracy and eliminate the sliding mode integral saturation effect.The simulation results show that the FP-PMSM speed sensorless FCS-MPTC system based on FOSM-MRAS has strong robustness,good dynamic performance and static performance,and high reliability.

Magnetic field and performance analysis of a tubular permanent magnet linear synchronous motor applied in elevator door system

A novel elevator door driven by tubular permanent magnet linear synchronous motor (TPMLSM) is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet (PM), on magnetic field was studied and the best values were given by the finite element analysis (FEA). The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying.

Development of the High-performance Synchronous Permanent Magnet Planar Motor and Its Key Technologies

永磁同步平面电机具有直接驱动、出力密度高、低热耗、高精度等特点,在现代精密、超精密加工装备,特别是在极紫外光刻机中具有广阔的应用前景。根据永磁阵列和线圈阵列的结构形式将永磁同步平面电机划分为组合式、半组合式、绕组层叠式和对称式永磁同步平面电机4类,并介绍了各种类型平面电机的特点,总结了永磁同步平面电机关键技术的发展现状,针对目前永磁同步平面电机存在的不足,讨论了未来永磁同步平面电机发展的趋势与方向。

Study on three dimensional electromagnetic model for permanent magnet linear synchronous motor

In this paper, with the non-salient pole permanent magnet linear synchronous motor (PMLSM)being cited, by using Fourier transform method and "slot-by-slot", "pole -by-pole" current approach, a 3D electromagnetic field model of PMLSM is established. Special attention is paid to its structure and the influence of longitudinal and transverse end effect. The distribution of electromagnetic field of PMLSM can be obtained directly and promptly by using FFT algorithm. It can also be used for the analysis of other LSM.

The analysis of the line-start permanent magnetic synchronous motor basing on the FEM

In this article, the 2D transient FEM has been used to analyze the dynamic process of the three phase LS-PMSM running characteristic. By verifying it through the experiment, we obtain the conclusion that the simulation result is consistent with the experiment result. At the same time, by analyzing the situation of the magnetic bridge, we also obtain the result that the EMF waves are changing with the situation of the magnetic poles on and we can optimize the motor’s structure at the same time.

Magnetic Field and Operating Performance Analysisof Conical-rotor Permanent Magnet Synchronous Motor

In order to accurately analyze the magnetic field of conical-rotor permanent magnet synchronous motor(CR-PMSM),the effectiveness of two methods was studied on handling of problems concerned with non-uniform distribution of magnetic field along axial direction in CR-PMSM,which were sectional calculation(SC)method and three-dimensional finite element(3-D FE)method.On this basis,the influence of the axial displacement and dq-axis currents on the operating characteristics of axial magnetic force and torque is analyzed by using the 3-D FE model.Analysis results show that the axial magnetic force and torque decrease with the increase of axial displacement of the rotor,and the amplitude regularity of the axial magnetic force is affected by the d-axis current.A prototype machine is fabricated and tested,in order to validate the design theory.

Analysis of temperature field for a surface-mounted and interior permanent magnet synchronous motor adopting magnetic-thermal coupling method

Aiming at obtaining high power density of surface-mounted and interior permanent magnet synchronous motor(SIPMSM),it is important to accurately calculate the temperature field distribution of SIPMSM,and a magnetic-thermal coupling method is proposed.The magnetic-thermal coupling mechanism is analyzed.The thermal network model and finite element model are built by this method,respectively.The effects of power frequency on iron losses and temperature fields are analyzed by the magnetic-thermal coupling finite element model under the condition of rated load,and the relationship between the load and temperature field is researched under the condition of the synchronous speed.In addition,the equivalent thermal network model is used to verify the magnetic-thermal coupling method.Then the temperatures of various nodes are obtained.The results show that there are advantages in both computational efficiency and accuracy for the proposed coupling method,which can be applied to other permanent magnet motors with complex structures.

Design and Optimization of Line-Start Rare-Earth Permanent Magnetic Synchronous Motor Basing on FEM

The 2D transient FEM was used to analyze the starting process of the three phase rare-earth LS-PMSM.By verifying the simulation result with the experiment one, we get the conclusion that it is consistent with the experiment result very well.At the same time, by analyzing the situation of the magnetic bridge, we also get the result that the amplitude of EMF waves are changing with the situation of the magnetic poles and we can optimize the motor's structure at the same time.

Controlling chaos in permanent magnet synchronous motor based on finite-time stability theory

This paper reports that the performance of permanent magnet synchronous motor （PMSM） degrades due to chaos when its systemic parameters fall into a certain area. To control the undesirable chaos in PMSM, a nonlinear controller, which is simple and easy to be constructed, is presented to achieve finite-time chaos control based on the finite-time stability theory. Computer simulation results show that the proposed controller is very effective. The obtained results may help to maintain the industrial servo driven system＇s security operation.

Full-order sliding mode control of uncertain chaos in a permanent magnet synchronous motor based on a fuzzy extended state observer

A full-order sliding mode control based on a fuzzy extended state observer is proposed to control the uncertain chaos in the permanent magnet synchronous motor. Through a simple coordinate transformation, the chaotic PMSM model is transformed into the Brunovsky canonical form, which is more suitable for the controller design. Based on the fuzzy control theory, a fuzzy extended state observer is developed to estimate the unknown states and uncertainties, and the restriction that all the system states should be completely measurable is avoided. Thereafter, a full-order sliding mode controller is designed to ensure the convergence of all system states without any chattering problem. Comparative simulations show the effectiveness and superior performance of the proposed control method.

Fractional-order permanent magnet synchronous motor and its adaptive chaotic control

In this paper we investigate the chaotic behaviors of the fractional-order permanent magnet synchronous motor（PMSM）.The necessary condition for the existence of chaos in the fractional-order PMSM is deduced.And an adaptivefeedback controller is developed based on the stability theory for fractional systems.The presented control scheme,which contains only one single state variable,is simple and flexible,and it is suitable both for design and for implementation in practice.Simulation is carried out to verify that the obtained scheme is efficient and robust against external interference for controlling the fractional-order PMSM system.

Impulsive control of permanent magnet synchronous motors with parameters uncertainties

The permanent magnet synchronous motors （PMSMs） may have chaotic behaviours for the uncertain values of parameters or under certain working conditions, which threatens the secure and stable operation of motor-driven. It is important to study methods of controlling or suppressing chaos in PMSMs. In this paper, robust stabilities of PMSM with parameter uncertainties are investigated. After the uncertain matrices which represent the variable system parameters are formulated through matrix analysis, a novel asymptotical stability criterion is established. Some illustrated examples are also given to show the effectiveness of the obtained results.

Application of neural networks for permanent magnet synchronous motor direct torque control

Neural networks require a lot of training to understand the model of a plant or a process. Issues such as learning speed, stability, and weight convergence remain as areas of research and comparison of many training algorithms. The application of neural networks to control interior permanent magnet synchronous motor using direct torque control （DTC） is discussed. A neural network is used to emulate the state selector of the DTC. The neural networks used are the back-propagation and radial basis function. To reduce the training patterns and increase the execution speed of the training process, the inputs of switching table are converted to digital signals, i.e., one bit represent the flux error, one bit the torque error, and three bits the region of stator flux. Computer simulations of the motor and neural-network system using the two approaches are presented and compared. Discussions about the back-propagation and radial basis function as the most promising training techniques are presented, giving its advantages and disadvantages. The system using back-propagation and radial basis function networks controller has quick parallel speed and high torque response.

Comparison of Two Novel MRAS Based Strategies for Identifying Parameters in Permanent Magnet Synchronous Motors

Two model reference adaptive system （MRAS） estimators are developed for identifying the parameters of permanent magnet synchronous motors （PMSM） based on the Lyapunov stability theorem and the Popov stability criterion, respectively. The proposed estimators only need online measurement of currents, voltages, and rotor speed to effectively estimate stator resistance, inductance, and rotor flux-linkage simultaneously. The performance of the estimators is compared and verified through simulations and experiments, which show that the two estimators are simple, have good robustness against parameter variation, and are accurate in parameter tracking. However, the estimator based on the Popov stability criterion, which can overcome parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator, in contrast to only one integral unit in the estimator based on the Lyapunov stability theorem. In addition, the estimator based on the Popov stability criterion does not need the expertise that is required in designing a Lyapunov function.

Rotor Strength Analysis of High-speed Permanent Magnet Synchronous Motors

为了对转子进行有效的冷却，在满足电机电磁性能的前提下，可通过减小保护套的厚度来尽可能增大定转子之间的气隙，因而必须对保护套和永磁体进行强度校核。将转子受力状况简化为平面应变问题，在此基础上推导出了两层过盈配合、三层过盈配合转子的应力场、应变场、位移场的解析公式，并利用有限元方法验证了解析公式的正确性。归纳了高速情况下热套式永磁转子强度设计准则，为转子的优化设计提供了理论依据。以一台额定转速120kr／min、10kW的高速永磁同步电机为例，给出了两种常用过盈配合高速电机转子的强度设计方法。

Adaptive synchronization of chaos in permanent magnet synchronous motors based on passivity theory

An adaptive synchronization control method is proposed for chaotic permanent magnet synchronous motors based on the property of a passive system. We prove that the controller makes the synchronization error system between the driving and the response systems not only passive but also asymptotically stable. The simulation results show that the proposed method is effective and robust against uncertainties in the systemic parameters.