The traditional fault-tolerant procedure usually comprises fault detection and fault tolerance. Fault detection is adopted to locate the specific fault, which increases the complexity and ...misdiagnosis risk of fault-tolerant systems. This article introduced an adaptive fault-tolerant control for open-phase faults and open-switch faults in dual three-phase PMSM (DTP-PMSM) drives. The proposed fault-tolerant scheme is fulfilled by going through three operation states: healthy operation, transient xy open-loop faulty operation, and fault-tolerant operation. The angle of fault-tolerant reference currents on xy plane is obtained from the transient xy open-loop faulty operation. Unified fault-tolerant reference currents of open-circuit faults are built up by using the above reference angle. After the open-circuit faults occur, the unified fault-tolerant reference currents are directly applied to the drive system without fault localization. Experimental results demonstrate a very smooth switching capability of the developed adaptive fault-tolerant control from the faulty operation to the fault-tolerant operation without extra hardware.
The installment of LC filter between the voltage source inverter (VSI) and motor terminal can reduce the value of dv/dt considerably, and further mitigate the surge voltage stress on the motor ...windings during the long-distance transmission. However, the sophisticated controller needs to be designed to solve the additional resonance problems caused by the filter. In this article, the finite-control-set model predictive control (FCS-MPC) is adopted to realize the q-axis current reference tracking for motor and suppress the filter resonance simultaneously. Different from the transfer-function-based AD scheme, the mechanism of resonance generation is revealed in the time-domain, where the cost function of FCS-MPC is designed to directly regulate the multivariable trajectory of the system. Therefore, the proposed FCS-MPC controller expresses the intuitive design principle, a simple structure, and fewer tuning parameters, which could be an alternative to the existing AD scheme. To reduce the number of sensors, the Kalman-filter based state estimation is used by considering the one-step delay of the control input. The cost function is further optimized to obtain a lower computational burden. The experimental results prove that the proposed FCS-MPC scheme can ensure the motor-friendly waveform and overcome the resonance problem effectively.
Aiming at the speed regulation problem of the permanent magnet synchronous motor (PMSM) in the presence of torque ripple and external disturbance, a composite control algorithm is proposed by ...combining an iterative learning control based on disturbance observer (ILC-DOB) with a second-order sliding-mode (SOSM) control scheme, which can improve the robustness and the ability of torque ripple suppression for the PMSM speed regulation system. First, the mathematical model of the PMSM is constructed and then transformed into an SOSM dynamics with mismatched disturbance. Second, a novel ILC-DOB is introduced to estimate the mismatched disturbance containing periodic torque ripple. Finally, a composite SOSM control algorithm with state feedback and feedforward compensation is constructed. Consequently, the robustness of the PMSM system is improved, and the torque ripple is also minimized. On this basis, the performance of the PMSM speed regulation system is improved. Through experimental results, the effectiveness of the proposed composite control algorithm is verified.
Permanent magnet synchronous motor (PMSM) systems regarded as a prominent component of modern power drive systems have been widely applied. For the reason that voltage faults and squander of ...communication resources are common in PMSM drive systems engineering applications, a discrete-time event-triggered fault-tolerant control scheme considering voltage faults is applied to PMSM drive systems in this paper. Firstly, the PMSM discrete-time dynamic model considering voltage faults is established. Secondly, the command filter approximator is used to approximate the system nonlinearities and adaptive fuzzy technique is utilized to solve voltage faults problem. Then, by means of event-triggered mechanism, the network communication resources from the central controller to the remote actuator are saved. Besides, the "noncausal problem" in the design process of backstepping method can be overcome by the command filter approximator. Finally, it is proved that the tracking error converges to a small neighborhood of the origin, and all the signals of the closed-loop system are bounded. Experimental results demonstrate the effectiveness of the proposed scheme.
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.
A control strategy that combines a novel reduced-order vector resonant controller and a generalized active disturbance rejection control (ROVR-GADRC) is proposed in this paper to suppress the current ...disturbances containing periodic harmonics of permanent magnet synchronous motor (PMSM). Firstly, the ROVR controller is designed, which integrates the advantages of both the complex coefficient filter and the vector resonant controller. Compared with the existing resonant control methods, the proposed ROVR can separate and extract the positive and negative sequence harmonics, and avoid the phase delay and peak point simultaneously. Secondly, a generalized extended state observer (GESO) is introduced to enhance the suppression of low-frequency disturbance. Then, the composite control strategy is developed. Besides, the stability, disturbance rejection performance, parameters configuration, robustness and tracking performance of the proposed ROVR-GADRC are comprehensively analyzed. The proposed current controller simultaneously performs harmonics suppression of specific phase sequence and other unknown disturbances attenuation. Finally, the feasibility and effectiveness of the proposed method is verified on a PMSM platform through the experimental results.
In this paper, a novel optimization-based maximum-torque fault-tolerant control scheme is proposed for the open-phase fault of dual three-phase permanent-magnet synchronous motor (DTP-PMSM) drive. ...First, the relationship between torque output capability and single-phase copper losses under open-phase fault is derived with the consideration of overheating problems. Since the derived expression has multiple optimization goals, a new objective function is designed to simplify the current optimization. Second, Particle Swarm Optimization (PSO) is utilized to obtain the maximum-torque current references based on the designed objective function. Different from the conventional maximum-torque fault-tolerant schemes which limit the current patterns, the proposed fault-tolerant control scheme employs PSO to search for the global optimal result without adding any unnecessary restrictions such as sinusoidal current patterns. In this way, the proposed fault-tolerant control scheme can achieve the theoretical highest torque output capability of 73.3% with lower total copper loss. Both the theoretical and experimental results are presented to prove the effectiveness and superiority of the proposed optimization-based maximum-torque fault-tolerant control scheme.
This paper analyzes the noise and vibration in permanent-magnet synchronous motors (PMSMs). Electromagnetic forces have been identified as the main cause of noise and vibration in these machines, ...rather than the torque ripple and cogging torque. A procedure for calculating the magnetic forces on the stator teeth based on the 2-D finite-element (FE) method is presented first. An analytical model is then developed to predict the radial displacement along the stator teeth. The displacement calculations from the analytical model are validated with structural finite-element analysis (FEA) and experimental data. Finally, the radial displacement is converted into sound power level. Four different PMSM topologies, suitable for the electric power steering application, are compared for their performances with regard to noise and vibration.
Open-circuit fault is one of the most common faults in permanent magnet synchronous machine (PMSM) drives. The open-circuit fault can cause the obvious change of stator currents of PMSM. Hence, the ...previous artificial intelligence based-fault diagnosis method mainly relies on the samples extracted from stator currents. However, the large sets of the samples are required due to the variation of the PMSM operating point, increasing the complexity of fault diagnosis. What's more, stator currents are easily affected by the noise, decreasing the accuracy of fault diagnosis. To solve the issues, this paper proposes a robust open-circuit fault diagnosis method using wavelet convolutional neural network with small samples of normalized current vector trajectory graph. The proposed method uses current normalization to establish small sample sets and combines convolutional neural network with discrete wavelet transform to enhance robustness to noise. The proposed fault diagnosis method is validated by simulation and experiment. Both the results show that the proposed method can effectively diagnose 22 kinds of open-circuit fault types (including healthy mode), being with great antinoise ability and robustness to different working conditions.
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