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The temperature inside the transformer box can reflect its real-time operating status, so the temperature variation can be used to judge the safe operation of the transformer. The tank, iron core and winding of a natural oil circulation transformer are simulated and calculated, so that the temperature field distribution is obtained, which provides a reference for studying the running state of the transformer. It can be concluded that the transformer winding and core temperature are significantly higher than the transformer box temperature at the same height; the transformer winding temperature is higher than the core temperature, and the low-voltage winding temperature is the highest.

By the method of engraving a groove on the quartz glass plate, this paper artificially limits the development direction of carbonization channel, eliminating the interference of other directions. With the help of the distributed potential measurement system, and through actual measurement and simulation analysis, it is verified that the space charge generated by the discharge is the cause of the distortion of the distributed voltage waveform. Using the increment of waveform distortion measured at different positions, this paper gives a calculation method for calculating the position and the amount of space charge through theoretical formula derivation. Comparing the data which is calculated by this method in the test and the cardboard layered analysis, the correctness of calculation method is verified, and it is also proved that under this model, the position of space charge can largely characterize the length of the carbonization trace.

In order to solve the problem of fire rescue in power tunnels, it is necessary to study the design method of obstacle avoidance control system for fire-fighting robots. Poor response and effectiveness is one of the typical problems when using the current design method in the obstacle avoidance control system of power tunnel fire-fighting robots. A real-time method of obstacle avoidance control system for power tunnel fire-fighting robot is proposed in this article. The design of fire-fighting robot is completed through coordination and cooperation among power modules, lidar ranging modules, servo control modules and motor drive circuits. On the principle of artificial potential field, the obstacle range in power tunnel is divided into multiple window cells by grid method, the attractive force and repulsive force generated by the target point and obstacle in cells is calculated. According to the calculation results, the resultant force is obtained, which makes the fire robot avoid the obstacles in the power tunnel. Therefore, obstacle avoidance control system of the fire robot in the power tunnel is completed. The experimental results show that the proposed method is highly responsive and effective.

This paper focuses on the measurement principle, design ideas and test verification of distributed potential measurement systems. The system detects the potential change under the carbonization channel during the discharge process by detecting the voltage signal of the series capacitor on the distributed potential measuring circuit, and judges the length of the carbonization channel from the distribution of the power frequency electric field and the transient electric field distribution generated by the partial discharge. And the amount of discharge charge is measured.

In this paper, the energy calculation method based on the three-capacitor model is analyzed by theoretical calculation and circuit simulation, and the correct use range of the single/multiple energy calculation method is clarified. The Monte Carlo method was used to simulate the partial discharge. The reliability of the multiple discharge energy calculation method based on the three-capacitor model was confirmed by comparative analysis of the data. Experiments were conducted to investigate the relationship between carbonization traces and space charge and pulse energy. It is verified that there is a certain proportional relationship between the space charge and the apparent discharge amount in the early stage of the development of carbonization channels.

Classical convolutional neural networks used in computer vision tasks perform excellently in accuracy, but they are unsatisfactory in computational cost especially with the networks going deeper and the image size going larger. Special models based on visual attention have showed their advantages in dealing with spatial information for saving computational cost at inference time. These models are designed to imitate human visual attention mechanism, but they are not able to achieve realize adaptive receptive scope for different object size. In this paper, a recurrent location and scope selection approach is proposed to improve the attention efficiency, which is more similar to human visual mechanism. We evaluate our model on the basic visual recognition task, where it outperforms the baselines and could provide approximated bounding boxes in a weakly supervised way.

Compliance is an important property in machine, but mechanism to realize compliance is not adequate to the demand. In this paper, the variable stiffness linkage (VSL) was designed to achieve safety assurance, stability improvement and energy conservation in robots and mechanical applications. Stiffness change could be realized by changing the position of the slider on each leaf spring. In order to save the energy from holding the specific stiffness, a screw-slider-linkage-slider mechanism was applied. Design principle and mechanical realization of VSL were presented. And then an effective stiffness model was designed. Finally the simulation was performed, which proved the effectiveness of VSL.

Among all the types of transformer insulation deterioration, partial discharge is relatively a direct one that may lead to carbon traces which have negative effect on insulation. We believe that the relationship between the trace length and total appearance charge of partial discharges is a key to diagnose the oil paper insulation's remained life, even though the carbon trace in paper or pressboard cannot be seen directly like the transparent material such as XLPE. In this paper, we put forward an electrical method based on the hypothesis that the space charges just stay where the partial discharge happened before. Based on a distributed potential measuring system, we pay attention to carbon traces developed in a single electrical tree. After a series of high voltage experiments, we calculate the position of the space charges by their electric field and then we get the trace length by the farthest space charges. Finally, we get the result of experiment consisted with that of the theory calculations.

The dynamic gesture track training based on HMM (hidden Markov model) is one of the key techniques in dynamic gesture recognition. This paper adapts the iteration algorithm of Baum-Welch on the HMM to train and do some research to the performance of dynamic gesture track training from iteration times, sample number selection and model initial value selection. The experimental results show that the HMM is very efficient to the dynamic gesture track recognition with spatio-temporal characteristic.