Speed Sensorless Control Scheme Research Articles

Speed Sensorless Control System of Five‐Phase Induction Motor Based on Linear Active Disturbance Rejection Control and Adaptive Full‐Order Observer

As the simplest type of multi‐phase induction motor, the five‐phase induction motor is suitable for applications that require high power and reliability due to its advantages such as low noise, low torque ripple, and strong load capacity. To address the problem that the speed encoder is easily affected by external environmental interference, a speed sensorless vector control strategy combining linear active disturbance rejection control and adaptive full‐order observer is proposed. Compared with the traditional speed sensorless vector control strategy, this paper's proposed method designs three first‐order linear active disturbance rejection controllers instead of traditional proportional‐integral controllers for speed control. Experimental results show that the proposed strategy exhibits stronger anti‐interference ability under load disturbance, improving the overall robustness of the speed sensorless control system. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Sensorless Control With Adaptive Speed Observer Using Power Winding Information for Dual-Stator Winding Induction Starter/Generator

This paper presents a speed-senserless control strategy with an adaptive speed observer using power winding (PW) information for dual-stator winding induction starter/generator (DWIG), in order to improve speed estimation precision and starting-generating performances. Based on the principle of model reference adaptive system (MRAS), an improved rotor-flux-based reference model is proposed by utilizing the electromagnetic link between the control winding (CW) and PW, the PW voltages are used to estimate rotor flux without necessity of stator resistance and filter parameters. The improved speed observer is less parameter-sensitive and can reduce the estimation error, especially in low-speed starting process with load. The parameter design method of the adaptive mechanism of proposed speed observer based on stability analysis is also given. The distribution of dominant pole of the speed observer is modified to obtain good tracking ability. Based on the improved speed observer, a speed-sensorless starting-generating control strategy is investigated, in which the estimated speed is not only used in speed control in starting process but also in staring-to-generating switching process. The simulation and experimental results verify the validity of the proposed speed observer and the speed-sensorless control strategy.

Low Speed Sensorless Control Scheme Based on Infinite Position Set in Harmonic Subspace for DTP-PMSHM

Low Speed Sensorless Control Scheme Based on Infinite Position Set in Harmonic Subspace for DTP-PMSHM

Research on speed sensorless control strategy of permanent magnet synchronous motor based on fuzzy super-twisting sliding mode observer.

Aiming at the problems of poor adjustment effect, weak anti-disturbance ability, and low robustness of the traditional sliding mode algorithm for permanent magnet synchronous motor speed sensorless, a permanent magnet synchronous motor speed observation method combining super-twisting sliding mode control algorithm and fuzzy control is proposed to accelerate the convergence speed of the system and improve the anti-disturbance ability. Fuzzy rules are used to solve the problem of obtaining the upper bound of the boundary function in the super-twisting algorithm. Moreover, the fuzzy algorithm is used to output the variable sliding mode gain instead of the fixed sliding mode coefficient to improve the system robustness and suppress the jitter. The simulation results show that the overshoot of the control system is 4%, the lag time is not more than 0.003 ms, the speed error is not more than 1%, and the response and adjustment time is not more than 0.02 s. The proposed control strategy improves the tracking accuracy and response speed of the system, suppresses the sliding mode chattering, and enhances the anti-interference ability of the system.

Sliding Mode Control for Sensorless Speed Tracking of PMSM with Whale Optimization Algorithm and Extended Kalman Filter

This paper proposes a sensorless speed control strategy for a permanent magnet synchronous motor system. Sliding mode control with a whale optimization algorithm was developed for robustness and chattering reduction. To estimate the position and speed of the rotor, an extended Kalman filter using Gaussian process regression was designed. In this controller, the whale optimization method adjusts the switching gain to minimize the tracking error. However, it provides chattering reduction and robustness, owing to the adaptive gain. The extended Kalman estimator calculates the rotor speed by using the current and voltage of the motor as an observer. The observer ensures the high reliability and low cost of the controller. The noise covariance and weight matrices that validated the performance of the estimation were optimized using a regression algorithm. The Gaussian process regression was trained to approximate the best covariance and matrices from the results of the motor controller execution. The performance of the proposed method was demonstrated through simulations under several conditions of tracking speed and load torque changes.

Speed Sensorless Control Method of Synchronous Reluctance Motor Based on Resonant Kalman Filter

When estimating the active back electromotive force (AEMF) of synchronous reluctance motor (SynRM) at medium and high speed, the traditional Kalman Filter (KF) will produce large phase delay due to the low-pass filter characteristics. A novel speed sensorless control scheme of SynRM based on resonant Kalman filter (RKF) is proposed in this paper. Firstly, the AEMF observer based on KF is designed and the bandwidth performance is analyzed. To solve the phase delay problem caused by KF, a generalized integral resonance perturbation estimator (GIRPE) is introduced to the framework of KF and the proposed RKF is formed. The estimation error of AEMF is compensated through GIRPE in the current error feedback loop of KF observer. In this way, the high-precision position estimation at high speed range is obtained. Finally, an improved dynamic position compensator (IDPC) is proposed to enhance the position estimation performance under dynamic case. The effectiveness of proposed scheme is validated at a 1.5kW SynRM drive, and the computational burden of the proposed method is assessed quantitatively.

A Sensor-less Surface Mounted PMSM for Electronic Speed Control in Multilevel Inverter

Recent advancements in power electronics technology evolves inverter fed electric motors. Speed signals and rotor position are essential for controlling an electric motor accurately. In this paper, the sensorless speed control of surface-mounted permanent magnet synchronous motor (SPMSM) has been attempted. SPMSM wants a digital inverter for its precise working. Hence, this study incorporates fifteen level inverter to the SPMSM. A sliding mode observer (SMO) based sensorless speed control scheme is projected to determine rotor spot and speed of the multilevel inverter (MLI) fed SPMSM. MLI has been operated using a multi carrier pulse width modulation (MCPWM) strategy for generation of fifteen level voltages. The simulation works are executed with MATLAB/SIMULINK software. The steadiness and the heftiness of the projected model have been investigated under no loaded and loaded situations of SPMSM. Furthermore, the projected method can be adapted for electric vehicles.

PMSM Speed Sensorless System of Intercity Railway Track Inspection Trolley Based on FOSMO-MRAS Observer

For realizing the speed sensorless control system of the intercity railway track inspection trolley, reducing the manufacturing cost and volume weight of the track inspection trolley, and improving the performance of the three-phase permanent magnet synchronous motor (PMSM) control system inside the track inspection trolley, a new fractional sliding mode variable structure model reference adaptive (FOSMO-MRAS) method is proposed to construct the motor speed observer, and a new sliding mode approach law is constructed by using a hyperbolic tangent function instead of a traditional discontinuous switching function. The simulation results show that the speed sensorless control strategy of PMSM based on the FOSMO-MRAS observer has good dynamic and static performance. And the robustness and reliability of the system are improved.

Experimental implementation of low-cost and robust sensorless control based on SOGI-FLL estimator for electric vehicles

Sensorless control techniques of electric motor dedicated to electric vehicles (EVs) offer low-cost and high operating performance. In this paper, a low-cost and robust speed-sensorless control scheme based on a second-order generalized integrator-frequency-locked loop method (SOGI-FLL) is proposed with only one current sensor. The SOGI-FLL is introduced to estimate accurately the motor angular speed from a measured current signal. While the scalar control technique, based on a single loop speed regulation, is used to determine the <em>‎</em>control signals. According to the proposed control scheme, the overall system will be very effective in terms of low-cost control and easy practical implementation, which have a great impact on electric vehicle applications. dSPACE micro labox platform is used to implement the proposed control scheme to drive an induction motor. The obtained results confirm the effectiveness and high performance of the proposed control to properly estimate the angular speed and drive the induction motor.

Speed sensorless control of a BL-IM based on an adaptive nonsingular terminal sliding mode observer

ABSTRACT Aiming at the speed detection accuracy of the optical encoder in a bearingless induction motor (BL-IM) affected by external environment and other factors, a speed sensorless control strategy based on an adaptive nonsingular terminal sliding mode observer (ANTSMO) is proposed. Firstly, a second-order nonsingular terminal sliding mode surface is constructed based on the stator current error. According to the designed sliding mode control law, the stator current and its common coupling term with the rotor flux are observed. Secondly, in order to avoid the bias effect caused by the pure integrator, the model reference adaptive system (MRAS) identification structure is used to realise the speed closed-loop observation . The adaptive sliding mode gain is designed by the identified speed. The stability and convergence of the observation system are proved through the Lyapunov theorem and Popov superstability theory. Finally, simulation analysis and experimental verification of the proposed strategy are carried out on MATLAB/Simulink and the test prototype. The results show that the proposed strategy not only can effectively reduce the observation chattering, and the speed can be accurately estimated under no-load, sudden load and variable speed conditions, but also the BL-IM can achieve good suspension characteristic of the motor rotor.

Speed Sensorless Control Based on Initial Rotor Position Detection for EESM

Electrically excited synchronous motor (EESM) is widely used in many large equipment drives because of its strong overload capacity, high efficiency, and adjustable power factor. The research and development of a high-performance EESM control system can realize the high combination of energy-saving speed regulation and green environmental protection and has a high social effect and economic value. In this paper, the signal injection method is used to obtain the initial rotor position information of EESM. Sliding Fourier transform is used to improve the initial position angle detection method based on the rotor signal injection method, and the improved method is compared with the traditional voltage integration method. Rotor high-frequency signal injection method was used to detect the rotor position information of the motor during operation, and the influence of the damping winding on the rotor signal injection method was analyzed. On the premise that the damping winding had no influence on the method, a method of obtaining the rotor position information of EESM without a speed sensor was designed. Finally, the speed sensorless regulation system using the initial rotor position detection method is simulated, which verifies the accuracy of the proposed speed sensorless control scheme.

Implementation of a DSP‐based speed‐sensorless adaptive control for permanent‐magnet synchronous motor drives with uncertain parameters using linear matrix inequality approach

This paper presents a novel speed sensorless adaptive control scheme for the uncertain permanent-magnet synchronous motor (PMSM) drive system using a linear matrix equalities approach with a digital signal processing (DSP) chip. The dynamic model of the PMSM drive with eight error states based on the structure of speed estimator, speed and current controllers is developed. The speed controller, current controller and rotor speed and position estimators are considered simultaneously and designed together. In addition, a three-parameter observer is also designed and the adaptive control law is derived in the light of Lyapunov stability theorem. The objective of this study is to determine the two estimation gains and the six control gains such that the closed-loop system is stable. The stability condition of the system can be characterized in terms of some linear matrix inequalities (LMIs). The LMIs problem can be efficiently solved with the help of MATLAB simulation tool. Differently from the conventional proportional-integral controller, a novel controller with a low-pass filter instead of a pure integrator is proposed. By a suitable adjustment for a design parameter, the steady-state error can also be improved. Numerical solutions of the controller and the estimator gains and simulation examples are provided to illustrate the design procedure and corresponding performances. The experimental results by using a TI TMS320F28335 DSP chip with the speed reference 400, 700, 1000 RPM, respectively and sudden change of the reference demonstrate the performance of the proposed control scheme.

Speed sensorless control of a bearingless induction motor with combined neural network and fractional sliding mode

To address the problem of speed and flux observation in sensorless control of a bearingless induction motor under the influence of parameter changes and external disturbances, a speed sensorless control strategy combining radial basis function (radial basis function, RBF) neural network and fractional sliding mode is proposed. According to the current error, fractional sliding mode control rate is designed to reduce the speed-observed chatter of the bearingless induction motor and its adverse effect on the rotor suspension stability. Then, combined with the theory of RBF neural network, the new optimal control rate is obtained by using its approximation ability. At the same time, the stability of two control rate is proved. Thus, the flux linkage and speed under normal operation, parameter change and external disturbance are observed and the new speed sensorless control is realized. The simulation and experimental results show that the proposed joint RBF neural network approximation algorithm and fractional sliding mode speed sensorless control system of the bearingless induction motor can not only effectively identify the flux and speed under three conditions of no-load, load disturbance and speed change, but also ensure the good suspension of the motor rotor in the x-axis and y-axis directions.

Study on speed sensorless system of permanent magnet synchronous motor based on improved direct torque control

The traditional direct torque control system of permanent magnet synchronous motor has many problems, such as large torque ripple and variable switching frequency. In order to improve the dynamic and static performance of the control system, a new torque control idea and speed sensorless control scheme are proposed in this paper. First, by deriving the equation of torque change rate, an improved torque controller is designed to replace the torque hysteresis controller of the traditional direct torque control. The improved direct torque control strategy can significantly reduce the torque ripple and keep the switching frequency constant. Then, based on the improved direct torque control and considering the sensitivity of the stator resistance to temperature change, a speed estimator based on the model reference adaptive method is designed. This method realizes the stator resistance on-line identification and further improves the control precision of the system. The performance of the traditional direct torque control and the improved direct torque control are compared by simulation and experiment under different operating conditions. The simulation and experimental results are presented to support the validity and effectiveness of the proposed method.

Speed sensorless control of a bearingless induction motor based on sliding mode observer and phase-locked loop

To realize the low-cost and high-performance of a bearingless induction motor (BIM), a speed sensorless control strategy combined with the improved sliding mode observer (SMO) and phase locked-loop (PLL) is proposed. Based on analyzing the principle of the traditional SMO, the improved SMO adopts a switching function that has a double boundary layer structure to reduce the high-frequency jitter. Firstly, the observation equation of the rotor flux is established where the stator current, as well as the rotor flux are two state variables, and then the system stability is discussed with the Lyapunov theory. Secondly, to reduce the rotor chatter and enhance the speed tracking performance a flux electrical angle detecting module is constructed based on the PLL structure that extracts the rotor flux electrical angle and speed from the observed flux component. Finally, the BIM speed sensorless vector control system is established and the simulation results and experimental results are respectively presented by the MATLAB/Simulink simulation platform and a laboratory prototype. Both results prove that this strategy can not only enhance the speed self-detection capability and tracking performance, but can guarantee the excellent self-suspension function as well.

Stator Flux Producing Current-Based Promoted Rotor Angle Estimator of Doubly-Fed Induction Generator for Encoderless Operations

In the context of position or speed sensorless control scheme, an improved rotor position estimation process for doubly-fed induction generator (DFIG) is presented in this paper. Model reference adaptive system (MRAS) is considered for the computation of rotor position. The stator flux producing current is taken as main working variable for the estimator. The estimator has various desirable features such as free from integrator-differentiator based computation, no information needed about initial rotor position (catch on fly operation), capability to work at very low slip condition (near synchronous speed operation), non-involvement of flux calculation, negligibly sensitive to mismatch in machine parameters. The major advantage of the proposed scheme is that it is insensitive to magnetizing inductance and rotor resistance of the electrical machine. Also, the novelty of the estimator lies in the fact that the suggested estimator works stably and accurately from very light load to full load operating conditions. The robust operation of proposed estimator is verified through real-time experimental set up.

Particle swarm optimization-based stator resistance observer for speed sensorless induction motor drive

This paper presents a different technique for the online stator resistance estimation using a particle swarm optimization (PSO) based algorithm for rotor flux oriented control schemes of induction motor drives without a rotor speed sensor. First, a conventional proportional-integral controller-based stator resistance estimation technique is used for a speed sensorless control scheme with two different model reference adaptive system (MRAS) concepts. Finally, a novel method for the stator resistance estimation based on the PSO algorithm is presented for the two MRAS-type observers. Simulation results in the Matlab/Simulink environment show good adaptability of the proposed estimation model while the stator resistance is varied to 200% of the nominal value. The results also confirm more accurate stator resistance and rotor speed estimation in comparison with the conventional technique.

Advanced speed sensorless control strategy for induction machine based on neuro-MRAS observer

High-performance field-oriented motor control requires accurate knowledge of flux and speed information. Furthermore, the elimination of sensors leads to reduced overall cost and size of the electric drive system and subsequently improving its reliability. So far, Speed sensorless control of induction motors has been faced with various techniques of speed estimation. However, the main drawbacks of these models are their insufficient performance at low speeds, along with sensitivity to parameters variation, which engenders an unsteady drive system. This paper proposes an effective sensorless indirect Field Oriented control scheme for an induction motor drive. The proposed speed observer combines artificial intelligence and model reference adaptive system (MRAS). This observer is associated with the control scheme as sensorless algorithms for rotor speed and flux estimation. This conjunction is intended to enhance the conventional MRAS performance especially in low-speed regions and reduce its sensitivity to noise and system uncertainties as well. Otherwise, the effectiveness of the proposed speed estimator is tested in simulation using Matlab/Simulink software environment. The control structure is checked in the low speed with load variation.

Speed Sensorless Control of Linear Ultrasonic Motors Based on Stator Vibration Amplitude Compensation

In some applications of linear ultrasonic motors (LUSMs), not installing speed/position sensors can reduce the size and cost of the system, changes in load will cause fluctuations in the speed of the LUSM. To eliminate the influence of load changes on speed, a speed sensorless control scheme based on stator vibration amplitude compensation (SSCBVC) is proposed. This scheme is implemented under the framework of the stator vibration amplitude-based speed control (VBSC) and frequency tracking. Based on the stator vibration amplitude-speed and the output force-speed curves of the LUSM, the relationship between the load changes and stator vibration amplitude (SVA) to be compensated is established, realizing a speed sensorless control of the LUSM under variable load conditions. The experimental results show that the maximum fluctuation of the speed is about 2.2% when the output force changes from 0 to 6 N with SSCBVC. This scheme can effectively reduce the influence of load changes on the speed of the LUSM without using speed/position sensors.

Speed-sensorless control system of a bearingless induction motor based on iterative central difference Kalman filter

ABSTRACT In order to obtain speed self-detecting with low cost for a bearingless induction motor (BIM) a speed-sensorless control strategy based on the iterative central difference Kalman filter (ICDKF) is proposed. Firstly, on the basis of the BIM mathematical model, the nonlinear state equation is established and its order is reduced from fifth-order to fourth-order using the stator terminal voltage and current as input. Then, a sterling interpolation formulation is used in the filter to reduce the model error, and an iteration loop link is adopted to improve the filter accuracy. Finally, the online speed of the BIM is identified through the filter rotor speed estimation. Theoretical analysis, simulation and experimental results by UKF and CDKF method have been compared. The results show that the proposed speed-sensorless control system not only has good speed tracking performance and reduce the load disturbance but also improves the BIM suspension performance.