The conventional model predictive control for dual three-phase permanent magnet synchronous motor suffers from poor operational performance and heavy computational burdens. Aiming to solve the two problems, this paper proposes an optimized control set model predictive control with a minimum error duty cycle strategy. First, a new form of 24 virtual voltage vector control set is constructed. All voltage vectors in the new control set are pointed in different directions and distributed uniformly, which are facilitated by combining with duty cycle modulation techniques. The control precision can be enhanced by employing the new control with more candidate vectors. Furthermore, a minimum error duty cycle calculation method is proposed in the scheme, where the currents of the dq-axis are considered simultaneously even if one active voltage vector is employed. So, the errors between the reference voltage and the selected voltage vector can be reduced. Thus, the operational performance can be significantly improved. Especially, a multistage group evaluation method is proposed to simplify the enumeration process, which guarantees the proposed strategy can evaluate more vectors with a less computational burden. Comprehensive experiments are carried out to verify the effectiveness of the proposed method.

This paper presents a hybrid control strategy for the LLC resonant converter in X-ray machines, addressing the limitations of voltage gain range under Pulse Frequency Modulation (PFM) and dynamic response under Phase Shift Modulation (PSM). The strategy employs an improved fruit fly optimization algorithm (IFOA) to optimize PI control and integrate Hybrid Phase-Shifted and Frequency-Modulated control. It dynamically adjusts the switching frequency and phase shift angle to maintain output stability and efficiency, ensuring optimal operation under rated conditions. A Matlab-based system simulation model confirmed the stability and accuracy of the IFOA in controlling the converter. Subsequent prototype testing validated the strategy’s effectiveness in reducing conduction losses, enhancing overall efficiency, and demonstrating practical feasibility and superiority.

TMR-based magnetic encoders provide sensitive SIN/COS signals, but practical accuracy is degraded by channel mismatch and decoder dynamics. This study evaluates an end-to-end embedded implementation on a PMSM (Permanent Magnet Synchronous Motor) bench. We consider amplitude mismatch, quadrature non-orthogonality, and harmonic/noise disturbances in the measured differential channels. We implement a lightweight compensation chain, including fixed-window moving-average filtering, min–max amplitude normalization, and correlation-based quadrature identification with sample-shift correction. We then compare four demodulation configurations under identical sampling and reference alignment to a 24-bit encoder: (A0) conventional second-order PLL (phase locked loop), (A1) compensation + open-loop atan2, (A2) compensation + fixed-${\omega }_n$ third-order PLL, and (A3) compensation + adaptive-${\omega }_n$ third-order PLL. Experiments with a TMR3081 sensor and an STM32 controller show clear differences among A0–A3. In steady operation, A3 removes the DC bias observed with A0 and keeps the angle error within approximately ±0.3° in the evaluated steady window. During commutation and ramp-like segments, PLL-based tracking (A0/A2/A3) is more robust than open-loop atan2 (A1), and bandwidth adaptation in A3 improves the acquisition–noise trade-off within the preset ${\omega }_n$ bounds. These results are reported for this prototype and the tested parameter settings.

This study presents an exponential sliding-mode observer with a continuous boundary layer for position-sensorless interior permanent magnet synchronous motor drives. The observer combines linear and fractional-power error feedback with a smooth switching function. The exponential reaching law provides finite-time convergence, while the continuous observer analysis establishes ultimate boundedness and finite-time entry into the prescribed boundary layer under bounded forcing. Compared with a super-twisting sliding-mode observer, the proposed method achieves smaller speed-estimation error, lower current distortion, and reduced calculated torque fluctuations in the reported tests. The speed-reversal experiments further demonstrate accurate rotor-position tracking at commanded speeds of ±500 and ±1000 r/min. Component-ablation results confirm the combined contribution of the linear reaching term and continuous smoothing mechanism to the estimation performance.