Conventional model-based sensorless surface-mounted permanent magnet synchronous motor (SPMSM) drivers suffer deteriorated estimation performance of speed and position in transient-state operation such as accelerating during wide-speed range or encountering large load torque disturbance. In this paper, an effective sensorless control solution is proposed to improve the robustness of sensorless SPMSM drivers in transient-state operation. Two extended state observers (ESOs) are utilized to estimate the αβ axis back-EMFs. An adaptive bandwidth tuning scheme is proposed to online tune the parameters of the ESOs, with which the desired estimation performance of back-EMFs can be achieved in wide-speed operation range. Additionally, the dynamic mechanical behavior of the sensorless control system during large load torque transient is investigated by using small-signal analysis, and then a corresponding speed estimation compensation scheme for the conventional quadrature phase-locked loop (QPLL) is developed, with which the capability of QPLL in tracking the rapidly-changing speed can be significantly enhanced. Experiments on a SPMSM demonstrate the superior robustness of the proposed method to that of the conventional method in transient-state operation.

The reference vector strategy has been widely used in the model predictive control (MPC) to reduce the computational burden. However, the reference vector derivation as well as the predictive model are sensitive to the machine parameters. This article presents a robust MPC with Luenberger observer to compensate the localization error of the reference vector for a six-phase permanent magnet synchronous motor (PMSM) drive. First, the two-step synthesis technique is employed to increase the tracking capability in the primary subspace and reduce the harmonic currents in the secondary subspace. Then, the influence of the control set design on the robustness is investigated, and it is confirmed that the more densely the voltage vectors locate, the easier the erroneous vector selection occurs. The Luenberger observer is adopted to compensate the localization error of the reference vector caused by the machine parameter mismatch. Subsequently, the cost function is defined in the form of the voltage vector error directly, thus greatly simplifying the control structure. In this way, the steady state performance as well as the parameter robustness are enhanced significantly. Experimentations are conducted to verify the validity of the proposed method.

Conventional active disturbance rejection controller (ADRC) for interior permanent magnet synchronous motor (IPMSM) drives suffers deteriorated performance in dealing with low-order harmonic disturbances. To enhance the capability of ADRC in rejecting such disturbances, this article proposes a complex coefficient active disturbance rejection controller (CCF-ADRC). The complex coefficient filter (CCF), which is capable of extracting signals with selective frequency and selective phase sequence from the input orthogonal signals, is incorporated into the extended state observer to enhance its estimation accuracy on the d-q -axis harmonic disturbances. With the harmonic disturbances accurately estimated, the subsequently designed CCF-ADRC can achieve enhanced performance in rejecting such disturbances. Theoretical analysis on the stability, the harmonics rejection capability, the command tracking capability, and the influence of parameter mismatches are systematically conducted. Comprehensive experiments on a 1.0-kW IPMSM verify the effectiveness of the proposed method.

This article proposes a hybrid evaluation method of electromagnetic force and vibration for electrical machines considering high-frequency current harmonics caused by the inverter. First, the permeance and armature magnetomotive force (MMF) is calculated based on the virtual MMF and the slot matrix. Then, the air-gap flux density and electromagnetic force construction process under arbitrary current is thoroughly studied. The vibration transfer function is obtained by utilizing the modal analysis and the modal test. Finally, the vibration can be calculated according to the modal superposition method. By applying this method to an interior permanent magnet machine, it can significantly reduce the computation efforts compared with the multiphysics procedure due to the extensive use of the finite-element method. In addition, the accuracy of this method is validated by conducting an experimental study.

The rotor topologies have a great influence on the vibration characteristics of permanent magnet assisted synchronous reluctance machines (PM-SynRMs). In this article, the vibrations of PM-SynRMs with different rotor topologies are studied and compared. First, the electromagnetic force harmonics of PM-SynRMs have been studied and the design rule about the combination of stator slots and “rotor virtual slots” is given to achieve low vibration. Then, a multiphysics model is established to calculate the vibration of the PM-SynRMs with different rotor topologies. The modal analysis is conducted through finite element method considering the orthotropic of materials and validated by the modal test. Besides, the prototype has been built and the vibration test is performed to confirm the accuracy of the vibration simulation. Based on the multiphysics model, the influence of the shapes of flux barriers and the number of “rotor virtual slots” is investigated. It proves that the design rule about the combination of stator slots and “rotor virtual slots” can achieve low vibration for PM-SynRMs.