Multiple power nonsingular terminal sliding mode control for reliable permanent magnet synchronous motor drive system

A non-singular terminal extended sliding mode control method based on variable exponential reaching law is presented because the permanent magnet synchronous motor speed control system is subject to parameter disturbance, external disturbance, and end effect. In order to accomplish global rapid convergence and get rid of singularity, a non-singular terminal extended sliding mode surface is first created. After the system reaches the sliding mode surface, a new extended state variable is constructed in accordance with the first-order angular velocity model, and a new better exponential reaching law is utilized to eliminate chattering. Finally, a disturbance observer is designed to detect the disturbance during motor operation in real-time and add it to the speed control loop as a compensation. The simulation findings demonstrate that, in comparison to the conventional sliding mode control strategy, the suggested variable-parameter non-singular terminal sliding mode control strategy lowers the effect of disturbance on the motor’s real operation and has the benefits of rapid convergence speed, good resilience, minimal speed overshoot, and high control precision.

An improved extended state observer is designed to eliminate the influences of speed control for a permanent magnet synchronous motor. The improved extended state observer is designed based on a new nonlinear function. This function exhibits better continuity and derivability than previously available functions and can effectively reduce the high-frequency flutter phenomenon. The nonlinear dynamics, model uncertainty, and external disturbances of the permanent magnet synchronous motor speed control system are extended to a new state. The improved extended state observer is utilized to observe this state. The overtime variation of the permanent magnet synchronous motor speed control system can be predicted and compensated in real time by the improved extended state observer. Therefore, the improved extended state observer, which is designed based on the new nonlinear function, can eliminate the disturbances on the permanent magnet synchronous motor speed control system. Finally, simulation experiments are performed and results show that the permanent magnet synchronous motor speed control system with improved extended state observer exhibits better performances.

To eliminate the effect of the uncertain disturbances and improve the control accuracy of spacecraft Attitude Control System, a nonlinear control algorithm named nonsingular terminal sliding-mode feedback controller is proposed in this work, which is mainly made up of nonsingular terminal sliding-mode controller and sliding-mode feedback controller. In the first place, nonsingular terminal sliding-mode controller is designed, which guarantees global asymptotic convergence of the attitude in the presence of the uncertain perturbations from the space. Despite that, it is the influence of the uncertain disturbances that hinder the control accuracy. Then, in order to promote the control accuracy, the sliding-mode feedback controller based on the principle of minimum sliding-mode error is proposed, which is used to compensate the control errors of the nonsingular terminal sliding-mode controller caused by the uncertainties. Hence, the determination principle of the weighting matrix in sliding-mode feedback controller is discussed, and the algorithm structure of the sliding-mode feedback controller is also analyzed, which provides the theoretical basis for the sliding-mode feedback controller. By contrast, an adaptive fuzzy algorithm is designed and introduced into the nonsingular terminal sliding-mode controller to improve the control accuracy, which named the nonsingular terminal fuzzy sliding-mode controller. Last but not the least, several numerical examples are presented to demonstrate the efficacy of the proposed nonsingular terminal sliding-mode feedback controller. Simulation results confirm that the control accuracy of the nonsingular terminal sliding-mode feedback controller is higher than the nonsingular terminal sliding-mode controller and the same as nonsingular terminal fuzzy sliding-mode controller. Not only is the calculation of the nonsingular terminal fuzzy sliding-mode feedback controller smaller than nonsingular terminal fuzzy sliding-mode controller, the adjusted parameters are also fewer than nonsingular terminal fuzzy sliding-mode controller obviously. The numerical results clearly indicate that the proposed nonsingular terminal sliding-mode feedback controller based on the principle of minimum sliding-mode error can compensate control errors accurately and quickly; therefore, it can reduce the effect of the uncertainties from the space indirectly.

In this thesis, performance of Permanent magnet synchronous motor (PMSM) drive is analysed. For producing constant torque PMSM requires sinusoidal stator currents. The thesis presents a mathematical analysis for the operation of the motor within the dq axis model. Because of high-efficiency, fast dynamic response and compact size, PMSM has become popular in industrial applications. There are various control strategies of speed control of Permanent Magnet Synchronous Motor. In this work, the strategy used is vector control method for speed control of PMSM motor drive. The vector control method consists of PMSM motor, inverter, speed regulator and coordinate transformation to build the PMSM drive for speed control. Speed regulation of the PMSM is performed through the designing of Proportional Integral (PI), Proportional integral derivative (PID), Sliding mode controller and Sliding mode controller plus PID controller as a speed regulator which is the part of the PMSM drive. Sliding-Mode controller (SMC) scheme is designed which eliminates the dependency of machine's parameters and effect of external disturbances, for speed control of PMSM drive system. Also, SMC plus PID controller is designed which gives the better result compare to the SMC. Work was carried out through simulation in the MATLAB environment.

This article focuses on realizing the chaos control of a permanent magnet synchronous motor by combining a pseudo-linear inverse system of the permanent magnet synchronous motor and synthetical sliding mode control. First, the permanent magnet synchronous motor dimensionless nonlinear mathematical model is established, and its chaos is analyzed by the Lyapunov exponent method. The permanent magnet synchronous motor parameter range when chaos appears is obtained. Then, the inverse system decoupling method is used to analyze the reversibility of the permanent magnet synchronous motor system, and the permanent magnet synchronous motor inverse system is obtained, which is compounded with the original system into a pseudo-linear inverse system that consists of two independent subsystems, including a first-order d-axis current system and a second-order rotational speed system, to decouple the permanent magnet synchronous motor system. Third, the first-order d-axis subsystem is controlled by sliding mode control with a hyperbolic tangent function as the switching function, and the second-order speed subsystem is controlled by super-twisting sliding mode control with a hyperbolic tangent function as the switching function, which is called the synthetical sliding mode control. The permanent magnet synchronous motor pseudo-linear inverse system is controlled by using the synthetical sliding mode to realize the chaos control of the permanent magnet synchronous motor. Finally, three kinds of permanent magnet synchronous motor chaos control systems are established in MATLAB/Simulink software, and the experimental tests are implemented. The results show that the proposed permanent magnet synchronous motor chaos control system has good performance, which can effectively eliminate chattering in sliding mode control and control chaos in the permanent magnet synchronous motor system.

This paper presents the finite-time control problem for permanent magnet synchronous motor (PMSM) speed servo system using different kinds of finite-time control methods. Integral terminal sliding mode controller and continuous finite-time controller are designed respectively for the speed loop and d-axis current loop. The proof of finite-time stability for PMSM speed servo system is also given. Compared with the corresponding control method of asymptotical stability, the controller based on the finite-time control can make the output of system track the desired speed reference signal in finite time and obtain a better dynamic response and anti-disturbance performance. Meanwhile, considering the large chattering phenomenon caused by high switching gains, a composite integral terminal sliding mode control method based on disturbance observer is proposed to reduce chattering. Through feed-forward compensation based on disturbance estimation, the composite integral terminal sliding mode controller may take a smaller value for the switching gain without sacrificing disturbance rejection performance. TMS320F2808 DSP experimental results are provided to show the superiority of the proposed methods.

To improve the performance of permanent magnet synchronous motor (PMSM) speed sensorless drives, the radial basis function (RBF) neural network control and backstepping control are proposed to design the controllers, and the model reference adaptive system (MRAS) observer is also constructed in this paper. The precise position control of PMSM drive system is a more complicated problem due to its significant nonlinear coupling. To get better control of PMSM sensorless drives drive system, the RBF neural network controller is constructed as the position controller to get the reference speed. In addition, the reference currents and voltages are obtained by backstepping controller. Further, the MRAS observer is developed for identifying the rotor speed of PMSM based on the Popov stability criterion. The overall control system possesses global asymptotic stability according to Lyapunov stability theory. Simulation results clearly exhibit that the controllers guarantee the excellent tracking performance of the reference position signals.

The paper proposes a new speed control method to improve control quality and expand the Permanent Magnet Synchronous Motors speed range. The Permanent Magnet Synchronous Motors (PMSM) speed range enlarging is based on the newly proposed power control principle between two voltage sources instead of winding current control as the conventional Field Oriented Control method. The power management between the inverter and PMSM motor allows the Flux-Weakening obstacle to be overcome entirely, leading to a significant extension of the motor speed to a constant power range. Based on motor power control, a new control method is proposed and allows for efficiently reducing current and torque ripple caused by the imbalance between the power supply of the inverter and the power required through the desired stator current. The proposed method permits for not only an enhanced PMSM speed range, but also a robust stability in PMSM speed control. The simulation results have demonstrated the efficiency and stability of the proposed control method.

In this article, in order to optimize the dynamic performance of the permanent magnet synchronous motor (PMSM) speed regulation system, a nonlinear speed-control algorithm for the PMSM control systems using sliding-mode control is developed. First, a sliding-mode control method based on a new sliding-mode reaching law (NSMRL) is proposed. This NSMRL includes the system state variable and the power term of sliding surface function. In particular, the power term is bounded by the absolute value of the switching function, so that the reaching law can be expressed in two different forms during the reaching process. This method can not only effectively suppress the inherent chattering, but also increases the velocity of the system state reaching to the sliding-mode surface. Based on this new reaching law, a sliding-mode speed controller (SMSC) of PMSM is designed. Then, considering the large chattering phenomenon caused by high switching gain, an improved antidisturbance sliding-mode speed controller method, called SMSC + ESO method, is developed. This method introduces an extended state observer to observe the lumped disturbance and adds a feedforward compensation item based on the observed disturbances to the SMSC. Finally, simulation and experimental results both show the validity of the proposed control method.

This paper presents the design and analysis of nonlinear controllers aimed at enhancing the performance of a Permanent Magnet Synchronous Motor (PMSM). A 3-phase, 900kW, 50Hz, 6-pole, 380 V, 756RPM PMSM with 48 rotor slots was modelled using MATLAB/Simulink and ANSYS. The study evaluates the motor transient and steady-state behavior in terms of torque, speed and current under different load conditions, with and without controller integration. Simulation result demonstrates that introducing controllers, particularly the Sliding Mode Controller (SMC), effectively reduces electromagnetic torque and output power ripple while achieving a faster response to steady state compared to the Proportional Integral Derivative (PID) controller. The SMC further enhances speed performance by increasing the load angle during rated operation, thus shifting the pull-out torque to power angle greater than 900. Maximum speed, torque, and current were achieved under 4Nm and 9Nm load conditions. The significance of this performance enhancement is underscored in applications such as robotics and conveyor systems, where variable speed operation is essential. Since PMSM speed is directly related to supply frequency and inversely to the number of poles, speed regulation is constrained by the number of pole-changing methods. Frequency variation remains the most effective approach for wide range speed control. The result obtained indicates that nonlinear control strategies offer superior performance over conventional methods, contributing to a more robust and responsive PMSM speed control system for industrial applications.

A novel reaching law‐based sliding mode controller is proposed for a permanent magnet synchronous motor (PMSM) speed regulation system with uncertainties and unknown load torque in this paper. The proposed reaching law is the improvement of the traditional power rate reaching law (PRL) by using a simple tuning function of the sliding variable. The tuning function is designed such that the reaching speed is fast when the system states are far away from the sliding surface, and vice versa. Theoretical analysis shows that the reaching time of the proposed reaching law is always shorter than that of the traditional PRL with the same gains. Moreover, unlike the traditional PRL and some existing auto‐tuning PRLs, the proposed reaching law can provide globally bounded reaching time independently on the initial conditions, and the reaching time can be effectively reduced by tuning the reaching law gains. Based on this novel reaching law, a disturbance observer is designed to estimate the total disturbance, and then based on the estimated disturbance and the novel reaching law, a sliding mode speed controller is designed for the robust control of PMSM speed regulation system. Simulations and experiments are carried out to demonstrate the superiority of the proposed control method.

In this paper, the permanent magnet synchronous motor (PMSM) servo system with backlash is studied. Since the mechanical transmission of the servo system uses gears, screw rods, on the one hand, the proper backlash can ensure the normal operation of the transmission mechanism; on the other hand, the existence of backlash nonlinearity will reduce the rigidity of the transmission mechanism, affect the tracking performance of the system, and even lead to mechanical resonance. In order to eliminate the influence of the backlash nonlinearity, the modeling and identification of the backlash nonlinearity are introduced, and the influence of the backlash is compensated in the regulator. In addition, in order to reject the possible model deviation and uncertain interference, reduce steady states fluctuations, a high-order sliding mode observer (HOSMO) based nonsingular terminal sliding mode control (NTSMC) is designed. After simulation verification, the compound controller proposed in this paper can effectively reduce the influence of the backlash nonlinearity and improve the position tracking performance of the system.

In this paper, a new design approach of an optimal V/f control for a super high speed permanent magnet synchronous motor (PMSM) is presented. The stator resistance of PMSM is generally neglected in design of a V/f control and compensated only by a boost voltage. However, due to the extra small size requirement of the proposed super high speed PMSM, stator resistance cannot be neglected any more. In this paper, the optimal design of a V/f control curve with consideration of the stator resistance is provided. The effect of the stator resistor to the V/f control curve is analyzed, it enables utilization of a simple and easy V/f control curve for an open-loop control of the super high speed PMSM. Simulation results are illustrated to show the effectiveness of the proposed design technique.

This paper focuses on the speed control of a permanent magnet synchronous motor (PMSM) for electric drives with model uncertainties and external disturbances. Conventional sliding mode control (CSMC) can only converge asymptotically in the infinite domain and will cause unacceptable sliding mode chattering. To improve the performance of the PMSM speed loop in terms of response speed, tracking accuracy, and robustness, a hybrid control strategy for a fixed-time-convergent sliding mode controller (FSMC) with a fixed-time-convergent sliding mode observer (FSMO) is proposed for PMSM speed regulation using the fixed-time control theory. Firstly, the FSMC is proposed to improve the convergence speed and robustness of the speed loop, which can converge to the origin within a fixed time independent of the initial conditions. Then, the FSMO is used as a compensator to further enhance the robustness of the speed loop and attenuate sliding mode chattering. Finally, simulation and experimental results show that the proposed method can effectively improve the dynamic performance and robustness of the PMSM speed control system.

For permanent magnet synchronous motor speed and rotor position easily affected by the mechanical sensor signal transmission precision, to improve the performance of permanent magnet synchronous motor drive, the speed control system satisfies the requirement of fast response, and the complicated condition of frequent load disturbance has stronger resistance, this paper designed a small nerve network optimization of permanent magnet synchronous motor intelligent control system. The intelligent control system will be small neural networks applied to the model reference adaptive control of permanent magnet synchronous motor speed control system. On this basis, the structures, permanent magnet synchronous motor control system simulation, the simulation results show the system can accurately measure the rotational speed, rotor position and compared with the traditional model reference adaptive control, motor start-up speed no overshoot, has the stronger ability to resist load disturbance and load disturbance after speed restore faster (6 ms), in the motor control has strong practical application value.