An improved neural networks-based vector control approach for permanent magnet linear synchronous motor

No-lapping concentrated windings permanent magnet linear synchronous motor (PMLSM) which possesses notable advantages such as big thrust force density, short winding head and small magnetic resistance is the preferred drive motor on Linear motor cordless upgrade system. In the paper 15 slots 16 poles PMLSM has been taken as example. On the basis of d-q dual-response theory, key parameters such as the motor resistance of q-axis (quadrature) and d-axis (direct) have been calculated by Finite Element Method. Thus mathematic model of PMLSM steady-state analysis has been built. PMLSM performances such as current, thrust force, power factor, efficiency, and electric power brake force affecting by supply voltage and ambient temperature change have been studied respectively both on load condition and no-load condition. The experiment results agree with theoretical analysis, with good prospects of permanent magnet (PM) linear synchronous motor for design and application of ropeless elevator.

In permanent magnet linear synchronous motor (PMLSM) direct drive system, disturbance caused by load disturbance and perturbation of motor parameters would reduce the control precision in a certain extent. In order to restrict the disturbance in PMLSM direct drive system, a vector control (VC) strategy based on the disturbance observer (DOB) was proposed in this investigation. By using the observed disturbance of DOB to adjust the given value of current in speed loop, the compensation for a sudden disturbance is optimized and a high precision of PMLSM drive system is obtained. For the sake of improving the dynamic performance under unknown disturbances, the traditional PID controller in speed loop was replaced by a single neuron PID controller, which leads to a good adaptive capability and a better starting performance in a given speed. Finally, a higher steady precision and robustness would be realized.

In this paper, the maximum thrust force per ampere (MTPA) strategy for saturated permanent magnet linear synchronous motors over the entire field weakening region is presented. In other words, influence of magnetic saturation on the MTPA and field weakening strategies as well as motor-inverter limitations is considered. Using the modified MTPA strategy leads to minimized copper losses, and so maximum capacity of motor is utilized. The proposed scheme incorporates all optimal strategies and operates the drive within the voltage and current limits of the motor/inverter. Simulation results for a prototype interior permanent magnet linear synchronous motor demonstrate that the MTPA and field weakening strategies can be successfully implemented for vector controlled saturated permanent magnet linear synchronous motor drives.

A new transfer model vehicle system for automatic horizontal transport, especially in short-turning-area applications, has been developed in the authors' laboratory. It is driven by permanent magnet (PM) linear synchronous motors (LSMs), and can operate efficiently in orthogonally-crossed-guideway network in mass-reduced mode. This paper presents a fundamental study of the PM LSM vehicle running on such network guideways with two crossings. The experimental results have shown a good agreement of the vehicle motion with the demand pattern in network running operation.

An automated commissioning procedure is proposed to tune the electrical and mechanical parameters of a linear surface-mounted permanent magnet synchronous motor drive, which is under vector control. The key tuning technique is to utilize a measure on the degree of distortion of controller output waveforms, which is developed from the first-order Walsh function series coefficient. The controller parameters are subsequently tuned based on the identified parameters and the pole-placement technique. An experimental prototype is implemented to test the validity of the proposed approach. Simulation and experimental results confirm the effectiveness of the proposed method in commissioning the vector-controlled linear permanent magnet synchronous motor drives.

The high-performance feature of the Permanent Magnet Linear Synchronous Motor (PMLSM) makes it a reliable and valuable motor for use in the automotive industry, especially for electric vehicle (EVs) applications. This research proposes a bond graph approach in modeling the PMLSM as a multi-domain dynamical system. However, A time-based simulation was performed using 20-sim software to simulate the dynamical behavior of the motor. An equivalent model of the motor was first obtained and then modeled and simulated using 20-sim software. The model of the PMLSM drive system was modeled separately and incorporated with PMLSM Motor equivalent model to form a global model. Moreover, the motor drive system response was studied based on the sensor resolutions and the inverter switching frequency. The block diagram and the transfer function methods validated the bond graph model obtained. Two classical PIs such as continuous and discrete were implemented on the motor response to control the velocity of the motor.

Linear motor eliminates the middle part of mechanical drive train, but because of structural characteristics of itself, must to take effective measures to reduce thrust fluctuations, or direct drive will lost its original meaning. In this paper, firstly research on detent force of moving magnet type permanent magnet synchronous linear servo motor and analyze the principle of generate detent force, secondly analyze the cogging force of moving magnet type permanent magnet synchronous linear motor and obtain the expression of cogging force maximum value, finally propose effective method to reduce detent force.

Aiming at the problems of poor stability and low system accuracy in the vector control of permanent magnet synchronous linear motor (PMSLM), a vector control strategy for PMSLM based on model reference adaptive system (MRAS) is proposed. Improve the accuracy of speed and mover position estimation by selecting the appropriate adaptive law, and introduce a sliding mode control (SMC) strategy in the speed loop to optimize the vector control system. The simulation results shows that this method can effectively reduce the overshoot and chattering, and improve the stability of the system.

Sensorless control of permanent magnet linear synchronous motors (PMLSMs) offers advantages such as reduced cost, stronger robustness, and easier maintenance. Existing back electromotive force (BEMF)-based sensorless control methods often assume three-phase circulant symmetry, which is not valid due to end effects, thereby losing accuracy. To reduce the reliance on symmetry assumptions and improve accuracy, this article first proposes a jumping curve jumping amplitude (JCJA) algorithm to reconstruct asymmetric three-phase flux linkages. Next, instead of using the traditional Clarke transform, this work proposes a new cotangent transform (CotT), which can precisely extract orthogonal and equal-amplitude <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\boldsymbol{\alpha}$</tex-math></inline-formula>-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\boldsymbol{\beta}$</tex-math></inline-formula> components without requiring three-phase symmetry. Experimental results on a PMLSM show a significant improvement in position and speed estimation accuracy compared with existing methods assuming symmetry. Finally, sensorless trajectory-tracking control is realized with accuracy and robustness, providing new insights into the field of precision sensorless control of linear motors.

This study presents a self‐evolving probabilistic fuzzy (PF) neural network with asymmetric membership function (SPFNN‐AMF) controller for the position servo control of a permanent magnet linear synchronous motor (PMLSM) servo drive system. In the beginning, the dynamic model for the PMLSM is analysed on the basis of field‐oriented control. Subsequently, an SPFNN‐AMF control system, which integrates the advantages of self‐evolving NN, PF logic system, and AMF, is proposed to handle vagueness, randomness, and time‐varying uncertainties of the PMLSM servo drive system during the control process. For the SPFNN‐AMF, the proposed learning algorithm consists of the structure learning and parameter learning in which the former is used to grow and prune the fuzzy rules automatically, whereas the latter is utilised to train the network parameters dynamically. Finally, detailed experimental results of two position commands tracking at different operation conditions demonstrate the validity and robustness of the proposed SPFNN‐AMF for controlling the PMLSM servo drive system.

Linear permanent magnet synchronous motors, especially those with low inductance and short pole pitch, exhibit significant ripple in flux and thrust force under conventional direct thrust force control. Aimed at reducing ripple in the flux and the force, a duty ratio control scheme for direct thrust force control of linear permanent magnet synchronous motors is proposed. The effect of inverter voltage vectors on the flux and the thrust force is analyzed. Subsequently, a precise expression for the online computation of the required duty ratio is derived. Compared to the state-of-the-art duty ratio control, the proposed approach eliminates the need to tune gains. The proposed online duty ratio calculation is based on the selected voltage vector from the switching table and takes into account the mover's speed. The proposed approach retains the characteristics of the conventional direct thrust control in terms of fast transient and steady-state responses for both flux and thrust force. Experimental results demonstrate a faster transient response and negligible steady-state error for flux, force, and speed responses under the proposed approach when compared to the state of the art.

Based on the analysis of power angle characteristics of the low-speed permanent magnet linear synchronous motor (PMLSM). An approach is made to determining motor steady operation sections and the basic methods to prevent out of step for the low-speed PMLSM. And the out-of-step prevention strategy is set up by using the fuzzy control theory, which adopts dual-mode control structure. With the variable voltage and frequency, the motor's out-of-step preventive control is realized. Experimental results show that the method is simple, high quality. It could effectively avoid out-of-step occurrence, and the research result is valuable to engineering application.

The long primary permanent magnet linear synchronous motor (PMLSM) used for high speed maglev train needs to adopt flux weakening (FW) control to increase its speed due to the limitation of the traction inverter output voltage. In this paper, a subsection FW scheme in the linear modulation region based on the direct traction control (DTC) is proposed. By controlling the reference primary flux directly in different working states, the target speed is achieved faster compared with SFOC-FW control, and the demagnetization current is saved. The primary flux and traction fluctuation are reduced in the low speed working condition by leading the space vector modulation (SVM) algorithm into the proposed DTC-FW scheme. The simulation analysis is carried out and the effectiveness of the proposed scheme is verified.

Considering internal parameters variation and external disturbance will greatly affect the performance of permanent magnet linear synchronous motor (PMLSM) control system, the active disturbance rejection control (ADRC) strategy is studied in this paper to enhance the anti-disturbance ability and dynamic performance of the system. Compared with the traditional PI control, ADRC has smaller overshoot, better adaptability, greater robustness to parameters variation and stronger anti-interference ability. The corresponding Simulink model is set up and its Simulink results are analyzed to prove the above advantages.

Active disturbance rejection control (ADRC) has been widely used in the permanent magnet linear synchronous motor (PMLSM) drive system for its strong anti‐disturbance ability and fast response speed. However, a large number of adjustment parameters add difficulties to its application. To solve this problem, a novel sliding mode‐based active disturbance rejection control (SM‐ADRC) with autotuned parameters is proposed in this paper. In this control strategy, the SM is incorporated with extended state observer (ESO) and nonlinear state error feedback (NLSEF) to reduce the number of adjustment parameters. The simulated annealing particle swarm optimization (SAPSO) algorithm is carried out to achieve the optimal configuration and realize parameter self‐tuning. The experimental results of the PMLSM speed servo system demonstrate the proposed control method has better suppression of chattering effect, disturbance rejection ability and fast dynamic response. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.