Gearbox oil temperature is one of the important indicators for gearbox condition monitoring and faults early warning. Accurately predicting the gearbox oil temperature change trend can maintain the gearbox in advance and ensure the safety and reliability of the wind turbine gearbox. The purpose of this article is to analyze the supervisory control and data acquisition (SCADA) data in wind turbines. A method based on multi‐input improved ant lion optimization and support vector regression (M‐IALO‐SVR) proposed, which can accurately predict the gearbox oil temperature. The prediction method is compared with back propagation neural network (BPNN) and ALO‐SVR methods to verify the effectiveness of the M‐IALO‐SVR method. To further analyze the prediction results, the 95% confidence interval processing is performed on the residuals of the prediction model, and then the trends of the mean and standard deviation of the moving window residuals are calculated. Testing SCADA data from a wind farm in northeast China, the test results show that when the gearbox is operating normally, the predicted value of the gearbox oil temperature follows the measured value very well. When the gearbox operates abnormally, its temperature deviates from the normal range, and the statistical characteristics of the residuals also change. According to the trend of the residuals statistical characteristics, the abnormal state of the gearbox can be found in time.

The opening and closing of a vacuum circuit breaker in the selected phase of the system voltage and the associated electrical equipment plug in or disconnect the electrical system with minimal impact on itself and the system. To realize this and ensure the control precision and stability of its action process, this study designs the drive motor and controller of a vacuum circuit breaker actuator. Additionally, a new function-switching pseudo-differential control (FPD) strategy is based on the feedback element principle. The control strategy avoids the direct differentiation of the controlled variables and has the ability of a fast dynamic response and anti-interference. At the same time, according to the moving process of the circuit breaker contacts, the control parameters are directly assigned to the system in stages, which reduces the amount of calculation and enhances the response speed of the control system. According to the research on the motor actuator movement process, the motor actuator and its control system of a 40.5 kV vacuum circuit breaker are developed and verified by closing operation in the selected phase, and the experimental results show the effectiveness of the proposed control strategy.

Given the problems of high loss density and heat dissipation difficulties in high-speed switched reluctance motors (HSRMs), it is essential to design an effective cooling system and accurately predict temperature rise. In this paper, a 3kW, 20000 r/min HSRM is investigated, and a cooling system design and temperature field analysis method for HSRM considering the coupling of electromagnetic-thermal-flow (EM-TF) is proposed. First, an electromagnetic simulation model is established, incorporating an AC copper loss calculation method based on fine winding modeling and a windage loss calculation method using full air-domain modeling to enhance accuracy. The calculated losses are then used as heat sources for thermal simulation. Subsequently, based on the unidirectional electromagnetic thermal-flow coupling (UEMTFC), the flow and thermal field performances of spiral, axial and circumferential waterways are compared, and the structural parameters of the optimal waterway are determined. Finally, the temperature rise is calculated using UEMTFC and BEMTFC, and the results are compared with experimental data. BEMTFC introduces flow field coupling, and accounts for the influence of temperature on the motor material and internal air properties during the iteration process, achieving higher accuracy. The deviations from the measured values are less than 4°C, demonstrating its effectiveness in HSRM thermal analysis.

To improve the path-following performance of autonomous underwater vehicles (AUVs) under ocean currents, a control method based on line-of-sight with fuzzy controller (FLOS) guidance and the fuzzy sliding mode controller (FSMC) is proposed. This method considers multiple factors affecting guidance and adaptively determines the optimal heading angle through the fuzzy controller to enhance guidance capability. Additionally, a novel FSMC based on Lyapunov stability theory is designed to suppress the influence of model uncertainty and external disturbances on the control system. Simulations and experiments of the proposed control method demonstrate that it can maintain precise tracking under disturbances, improving path-following performance metrics by more than 15%.

Switched reluctance motor has been widely used in various fields because of its simple, solid structure and high reliability. However, the disadvantage of large torque ripple limits its application in high-speed occasions. In this paper, a new type of rotor dislocation permanent magnet assisted high-speed reluctance motor (RDPMA-HSRM) is proposed, which realizes the axial magnetic flux through the structure of two groups of stator and rotor, and a permanent magnet is connected in series for auxiliary excitation. On this basis, the rotor dislocation is developed and a unique structural design is developed. The working principle of the motor is explained, the magnetic circuit model of the motor is analyzed, the mathematical model of the motor is given, and the contribution of permanent magnet assistance to torque is discussed. The magnetic characteristics of the motor in terms of flux density, flux linkage, inductance and torque are obtained by finite element simulation, and compared with the characteristics of the improved motor. The effects of rotor misalignment and permanent magnet auxiliary excitation on the performance of the motor are analyzed. Finally, the prototype is tested and the experimental results are obtained. Simulation and experimental results show the RDPMA-HSRM has smaller torque ripple and higher torque density.

A torque sharing function (TSF) with online compensation of excitation current control method is proposed for torque ripple reduction in electric excitation auxiliary switched reluctance motor (SRM) drives, which mitigates the problem of severe torque ripple inherent in traditional TSF control during the commutation of armature winding. The torque formula of the motor is derived and the finite element analysis of the static torque under different excitation currents is carried out, which proves that the output torque can be changed by adjusting the excitation current. Therefore, the proposed method is based on cosine TSF control, which uses a sliding mode control algorithm to adjust the amplitude of the excitation current to online compensate the torque fluctuations during commutation. Besides, Simulink, Simplorer and Maxwell co‐simulation and experiments are carried out on the traditional TSF control and the proposed method. The results demonstrate that the proposed method is superior to the traditional TSF control and the electric excitation auxiliary SRM has better torque performance and smaller torque ripple under the proposed method.