Speed Sensorless Vector Control Research Articles

Current Sensor Fault-Tolerant Control Strategy for Speed-Sensorless Control of Induction Motors Based on Sequential Probability Ratio Test

In the speed-sensorless vector control of induction motors (IMs), the speed estimation accuracy suffers from the deteriorated current measurement caused by the current sensor faults, such as open circuit in one phase, DC bias, and odd harmonics. In this paper, a novel speed estimation strategy based on the current sensor fault-tolerant control is proposed to improve the speed estimation accuracy under the current sensor faults. First, to detect the current sensor faults in real time, the sequential probability ratio test is introduced to the system by using the innovations of the extended Kalman filter (EKF). Second, to ensure speed estimation accuracy, a double-cascading second-order generalized integrator (DSOGI) is employed to reconstruct the faulty current information when a fault is identified. Finally, the reconstructed current information is fed back to the sequential probability extended Kalman filter (SPEKF), which estimates the rotor speed of the IM, and high-accuracy speed estimation under the condition of current sensor faults is achieved. The effectiveness of the proposed strategy is validated by a series of experiments, which were conducted on a 3 kW induction motor drive platform.

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 and Wiley Periodicals LLC.

Detection of turn short circuit fault in PMSM variable speed sensorless vector control based on luenberger observer and adaptive Fuzzy Logic Controller

Detection of turn short circuit fault in PMSM variable speed sensorless vector control based on luenberger observer and adaptive Fuzzy Logic Controller

Evaluation of Start-Up Performance of Induction Motor Speed Sensorless Vector Control Using Adaptive Flux Observer Considering Inverter Voltage Error

Speed sensorless vector control for induction motors using an adaptive flux observer makes it difficult to output high and stable torque at a standstill condition when the output voltage error mainly due to dead-time of the inverter. This voltage error leads to a speed estimation error. Consequently, axis misalignment occurs, and a torque value that tracks the reference command value cannot be output. A method has been proposed to compensate for this voltage error by using a current command value; however, the compensation accuracy is limited because of the forward voltage drop and nonlinear characteristics of power switching devices. This study applies the conventional dead-time compensation to the model reference adaptive system, and the effect of varying the amount of compensation, instead of investigating the true dead-time length, on the start-up is evaluated using a 2.2 kW experimental system and through dynamic analysis.

Improved Design of Feedback Matrix of Adaptive Observer for Induction Motor

In order to address the issue of the induction motor speed sensorless vector control system’s poor dynamic performance at low speed, this research suggests a brand-new feedback matrix algorithm for the full-order adaptive observer. Firstly, the open-loop transfer function based on the back-EMF error is analyzed, the stability conditions of the induction motor operation are deduced, and a preliminary framework is established for designing the feedback gain. Secondly, in order to maximize the system’s dynamic performance, the damping ratio of the speed identification system is chosen as the subject of study. To achieve this, the pole of the second-order characteristic equation of the observer’s complex number system is set up to satisfy the premise of stable operation at low speed and inverted state. The outcomes of the simulations confirm the method’s efficacy.

Self-starting control strategy of variable speed pumped storage unit based on adaptive full order state observer

When the variable speed pumped storage unit operates in the electrical state, the self-starting control strategy is generally used to start the process from zero speed to grid connection, which saves the starting device of the traditional constant speed unit and saves the construction cost of the unit. For the self-starting control process, the traditional open-loop flux calculation method will produce cumulative errors in the amplitude and angle of the flux when the motor parameters change. To solve this problem, an adaptive full order state observer is designed to observe the motor stator flux, which has stronger parameter robustness. Based on the flux observation, the speed adaptive law is designed to estimate the rotor speed and position angle, and the speed sensorless vector control of variable speed pumped storage unit is accomplished. The simulation results show that compared with the open-loop flux calculation method, the full order state observer can greatly reduce the flux estimation error and accurately estimate the rotor speed and position angle.

Extremely low speed performance research of the speed sensorless vector controlled induction motor drive system

This paper proposes a new full-order adaptive observer algorithm to overcome the instability of speed sensorless vector control system of induction motor at low speed, especially at extremely low speed. The algorithm consists of the improved feedback matrix algorithm and the improved speed adaptive law algorithm. By establishing an observer state error equation considering the non-linear voltage error of the inverter and the stator resistance voltage drop, a feedback matrix was designed to reduce the effect of inverter's non-linear voltage error and stator resistance voltage drop on speed estimation. Meanwhile, this paper improves the traditional adaptive law. The basic idea is to add compensation amount equivalent to the non-linear voltage error, and the compensation amount is adaptive to the running speed and load to improve the motor speed estimation accuracy at low speed. Extensive experimental tests have been carried out to evaluate the performance of the proposed algorithm using a 2.2 kW induction motor experimental platform. The experimental results show that the algorithm presented in this paper can guarantee the stable operation of the motor under the rated-load and 180% rated-load at low, extremely low and 0 speed with good dynamic and static characteristics.

An enhanced sensorless control based on active disturbance rejection controller for a PMSM system: design and hardware implementation

PurposeThis paper mainly aims to deal with the problems of uncertainties including modelling errors, unknown dynamics and disturbances caused by load mutation in control of permanent magnet synchronous motor (PMSM).Design/methodology/approachThis paper proposes an enhanced speed sensorless vector control method based on an active disturbance rejection controller (ADRC) for a PMSM. First, a state space model of the PMSM is obtained for the field orientation control strategy. Second, a sliding mode observer (SMO) based on back electromotive force (EMF) is introduced to replace the encode to estimate the rotor flux position angle and speed. Third, an infinite impulse response (IIR) filter is introduced to eliminate high frequency noise mixed in the output of the sliding mode observer. In addition, a speed control method based on an extended state observer (ESO) is proposed to estimate and compensate for the total disturbances. Finally, an experimental set-up is built to verify the effectiveness and superiority of the proposed ADRC-based control method.FindingsThe comparative experimental results show that the proposed speed sensorless control method with the IIR filter can achieve excellent robustness and speed tracking performance for PMSM system.Research limitations/implicationsAn enhanced sensorless control method based on active disturbance rejection controller is designed to realize high precision control of the PMSM; the IIR filter is used to attenuate the chattering problem of traditional SMO; this method simplifies the system and saves the total cost due to the speed sensorless technology.Practical implicationsThe use of sensorless can reduce costs and be more beneficial to actual industrial application.Originality/valueThe proposed enhanced speed sensorless vector control method based on an ADRC with the IIR filter enriches the control method of PMSM. It can ameliorate system robustness and achieve excellent speed tracking performance.

Speed sensorless vector control of doubly fed induction machine using fuzzy logic control equipped with Luenberger observer

Speed sensorless vector control of doubly fed induction machine using fuzzy logic control equipped with Luenberger observer

Speed Sensorless Vector Control of Double Star Induction Machine Using Sliding Mode Observer Based Lyapunov Stability

In this paper, Speed Sensorless Vector Control of Double star Induction machine DSIM using sliding mode observer is presented. The search for the gains of conventional Luenberger observer in the sense of stability Lyapunov, oriented to sliding mode observer form, but the sign function caused the chattering effect, the replace it by function smooth are adopted. As a result, application of DSIM speed sensorless vector control using sliding mode has shown that is robust to load disturbances and / or reference speed change. The proposed control scheme is verified by simulation.

Adaptive Compensation Flux Observer of Permanent Magnet Synchronous Motors At Low Carrier Ratio

When the permanent magnet synchronous motor (PMSM) works in the high-speed region with low carrier ratios, the performance of the rotor flux observer has a great influence on the loading capacity and stability of the speed sensorless vector control system. The problem of the adaptive compensation flux observer (ACFO) of the PMSM at low carrier ratios is analyzed in this paper, and an ACFO with a feedback delay component is presented. After retuning the PI regulator parameters, the new expression related to carrier ratio is obtained, which can improve the performance of the flux observer at low carrier ratios and make the torque and current loop response faster. Meanwhile, the stability of different Euler approaches of the integrator for ACFO in the discrete domain is analyzed, and a new Euler with a coefficient is proposed to combine the merits of the backward Euler and the trapezoid Euler. It shows better performance at low carrier ratios. Finally, the effectiveness of the discrete ACFO is verified by experiments.

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.

Speed sensorless of induction motor with adaptive full order state observer

Speed sensorless vector control of induction motor not only maintains the excellent performance of vector control, but also overcome the disadvantage of speed sensorless. It can reduce the cost and improve the reliability. So speed sensorless control have been widely researched. The paper implement speed sensorless control by the adaptive full order state observer and give debug process. Experiment results shows that this approach have excellent performance.

Sensorless Speed Vector Control Based on MRAS of Asymmetrical Two-Phase Induction Motor

This paper presents the sensorless speed vector control of an asymmetrical two-phase induction motor based on model reference adaptive system (MRAS). A three-leg voltage source inverter with carrier based space vector pulse width modulation (SVPWM) is used to offer unbalanced two-phase voltages for eliminating electromagnetic torque pulsaions. In order to perform rotor field orientation control the asymmetrical two-phase induction motor model is treated as a balanced model. Design of controllers for speed and current loops is fully given.The proposed flux and speed estimators can satisfactorily operate in various conditions. The dynamic and steady state performances of the proposed method are verified by both simulation and experimental results. The simltaion and experimental results are in good agreement.

Sensorless Control of a Tubular Oscillatory LPMSM based on MARS and Deadbeat Current Predictive Control

In the vector control system of the tubular oscillatory linear permanent magnet (PM) synchronous motor (LPMSM), it is difficult for traditional mechanical sensors to accurately obtain the feedback information under harsh conditions. In this work, a speed sensorless vector control system is designed and applied to the tubular oscillatory LPMSM which adopts the model reference adaptive system (MRAS), and the deadbeat current predictive control (DCPC) is also adopted to replace the traditional PI current loop to establish the coordination controller, which overcomes the difficulties of global optimization and PI control parameter setting. And the method is proved by the simulation results and it gets better dynamic performance.

Speed Sensorless Vector Control of a PMSM Using MRAS based on Sugeno Fuzzy Inference System Adaptation Mechanism

Speed Sensorless Vector Control of a PMSM Using MRAS based on Sugeno Fuzzy Inference System Adaptation Mechanism

Speed-Sensorless Vector Control of an Induction Generator Including Stray Load and Iron Losses and Online Parameter Tuning

Field-oriented control (FOC) is standardly used in high-performance induction machine (IM) applications. However, the performance of FOC algorithms strongly depends on the level of agreement between the actual IM and the respective model used for the algorithm design. IM parameters' values are known to vary with the operating conditions, so their online identification is preferable. In addition, it is often preferred to acquire the rotor speed by estimation because speed sensors increase the cost and size of the system while reducing its reliability. Model-reference-adaptive-system (MRAS) estimators are popular due to their simple implementation, but they are sensitive to IM parameters and, hence, usually include a parameter tuning mechanism. This article proposes an indirect rotor-field-oriented controller with the parallel MRAS speed estimation and IM parameter tuning - implemented in an induction generator system. Both the control algorithm and the MRAS include the stray load and iron losses, magnetic saturation, and rotor resistance variation, whereas the MRAS additionally accounts for variations of the stator and stray-load resistances. The system performance is experimentally evaluated over wide ranges of the IM flux, speed, torque, and temperature.

Speed sensorless control strategy for six‐phase linear induction motor based on the dual reduced‐dimensional serial extended Kalman filters

This study proposes a speed sensorless vector control strategy for the six-phase linear induction motor (SPLIM) based on the dual reduced-dimensional serial extended Kalman filters (DRDSEKFs). Firstly, the low-order mathematical model of SPLIM is obtained according to the equivalent transformation of primary voltage, current and flux components in the stationary coordinate system. Then, the state equation is derived and the speed estimation based on the five-dimensional extended Kalman filter (EKF) is realised. To reduce the computation cost and improve the accuracy of speed estimation, a DRDSEKFs algorithm is proposed, with one two-dimensional EKF and one three-dimensional EKF operating serially in every control period. As the real-time performance of the algorithm is guaranteed, it is possible to overcome the hysteretic nature of the traditional EKF and improve the dynamic estimation performance. Simulations and experiments show that the proposed sensorless control strategy is feasible and effective.

Fast Restarting of Free-Running Induction Motors Under Speed-Sensorless Vector Control

In some applications of inverter-fed induction motor drive systems, a fast and smooth restarting of free-running motors may be required when their inverters are faced with short-term power interruptions. In this article, a novel restarting strategy is proposed, consisting of three steps. First, during the restarting process, the initial step requires the machine's speed estimation. To achieve this, a dc current injection-based method is used to estimate the rotor flux and subsequently the speed of the rotating machine. In this step, a filtering and a phase-locked loop are used to extract speed information. Next, to further improve the speed estimation accuracy, the speed-sensorless vector control with zero torque command is used. Finally, a full-order adaptive observer is utilized for speed estimation in the restored normal operation of the induction motor. Compared to existing/alternative methods, the proposed strategy much faster estimates the initial speed and is able to restore the normal smooth operation within 0.5 s. The effectiveness of the proposed method is demonstrated by simulation and experimental studies.

The full-order state observer speed-sensorless vector control based on parameters identification for induction motor

During the operation of speed-sensorless control system for induction motor, the stator and rotor resistance varies greatly with the change of temperature and the frequency of the rotor side, which affects the estimation of the stator flux and leads to the low accuracy of the speed estimation. A speed-sensorless vector control method based on parameters identification with the full-order adaptive state observer is proposed in this paper. In the model reference adaptive system of AC motor, the stator resistance and rotor flux are assigned as state variables to build the reference model, and a full-order flux observer is introduced to adjustable model. Lyapunov theory and Popov superstability theory are used to deduce the speed and rotor resistance adaptive rate. The feedback gain matrix is simplified to speed up the convergence rate of the system. The estimation values of speed and rotor resistance are taken as the proportional integral form, so that an interactive model reference adaptive system is constructed by speed and rotor resistance identification. While observing the rotor flux, it can not only ensure the accuracy of the reference model but also eliminate the disadvantages of the voltage model with integral terms, and the rotor speed can be estimated at the same time. The experimental results show that the accurate performance of speed and flux identification can meet the requirements of application; the proposed control method with the identification of speed and rotor resistance has little fluctuations phenomenon on motor torque in low speed and achieves better performance.