Diagnosis and Classification Decision Analysis of Overheating Defects of Substation Equipment Based on Infrared Detection Technology

Substation equipment is not only the main part of the power grid but also the essential part to ensure the development of the national economy and People's Daily life of one of the important infrastructure. How to ensure its normal operation and find the sudden failure has become a hot issue to be solved urgently. For thermal fault diagnosis needs to classify and identify different power equipment first, this paper designed an SVM infrared image classifier, which can effectively identify three types of common power equipment. The classifier extracts HOG features from the infrared images of power equipment processed by the above segmentation and combines them with SVM multiclassification to achieve the purpose of improving the recognition accuracy. The experiment uses the classifier to identify three kinds of equipment, and the results show that the comprehensive recognition accuracy of the classifier is more than 95.3%, which is better than the traditional classification method and meets the demand for classification accuracy. In this paper, the traditional method of relative temperature difference is improved by using the temperature data of the infrared image, which can automatically judge the thermal failure level of electric power equipment. Experiments show that the diagnosis system designed in this paper can classify faults and give treatment suggestions while judging whether there are thermal faults for three types of power equipment, which verifies the feasibility and effectiveness of the substation infrared diagnosis technology designed in this paper.

Vibration-Induced Heating of Energetic Materials: A Review

The transport of energetic materials—whether by truck over rough terrain, or attached to the undercarriage of a high-performance jet aircraft—carries a certain level of inherent risk as the repeatedly applied stresses from vibration may lead to heating, mechanical degradation, and potentially even the triggering of an ignition event. Increasing knowledge of the underlying physics which control ignition is allowing us to better understand, and thus reduce, the risk of a catastrophic event occurring. The Apollo and Space Shuttle programmes provided motivation for research into the topic in the 1960s and 1970s, and some recent studies have focussed on the grain-scale physics of ignition. However, much of the useful insight has arisen from work with other primary applications in mind. Therefore, this review aims to bring together literature from several fields, with the intention of better understanding vibration-induced heating (VIH) phenomena in energetic materials. Sensitivity, VIH in viscoelastic polymers and inert composites, and a technique known as vibrothermography which uses VIH to detect cracks, are all considered where relevant read-across can be found. Often being viscoelastic materials and composites with complex rheology, energetic materials subjected to vibrational loading tend to warm up, with potential for even greater temperature rises due to anisotropy-driven localised heating mechanisms. Binders soften as temperature rises, and the chance of damage increases, which may lead to runaway heating and thermal failure (if mechanical failure does not occur first).

Effect of Shell Temperature on Thermal Resistance and Junction Temperature for Power Diode

Accurate measurement of junction temperature can avoid thermal failure of diode. During aging test, junction temperature should be indirectly calculated by testing its thermal resistance. In this paper, junction-to-case thermal resistance (Rthjc) of XX diode is tested by T3ster based on transient dual interface method. Its Rthjc is about 1.23K/W at 25°C and contains PN junction thermal resistance, metal shell thermal resistance and Sn-based solder thermal resistance, respectively. These three types of thermal resistance decrease in order. Effect of shell temperature on junction temperature and Rthjc is then discussed. As shell temperature increases, temperature variation of PN junction before and after heating and corresponding thermal resistance Rthjc both increase.

Numerical investigation into thermal buckling of friction pairs in hydro-viscous drive under nonlinear radial temperature distribution

Thermal buckling deformation can significantly impact the operating performance of hydro-viscous drive. A thermal buckling finite element shell model was established with the nonlinear radial temperature as the thermal loading condition. The thermal buckling behavior of friction pairs was investigated under three different boundary constraints. Moreover, the influence of thickness and material parameters on the critical buckling temperature was discussed. The simulation results coincide with the failure modes of friction pairs in practice, and the most common ones are the coning mode and the potato chip mode. The ability to resist thermal buckling deformation can be improved as the thickness increases. In addition, the steel disc with outer edge simply supported is more prone to thermal buckling, because the critical temperature is minimum. The thermal expansion coefficient is the primary factor in thermal buckling study, which is inversely proportional to the critical temperature. These provide a theoretical basis for avoiding thermal failure of friction pairs in a hydro-viscous drive.

Mathematical Models for Assessing the Thermal Engineering Reliability of Boiler Units of Power Complexes

The analysis is carried out and the definitions of the concept of thermal engineering reliability, the determining parameter and the determining function of boiler units, are given. A classification has been developed for the determining parameters of steam and hot water boilers by level in the chain of cause-and-effect relationships in the event of a thermal failure. It is proposed to divide the determining parameters and functions of boilers according to their spatial localization into integral and local. A lot of models for defining functions with different mathematical properties (for example, the presence or absence of discontinuities of the second kind) are considered. The defining functions (reliability criteria) currently used in boiler construction have been identified. The analysis of the safety factors for overturning and stagnation in direct-flow and drum boiler units is carried out. The incorrectness of the currently used dependence is shown. A formula has been proposed for these coefficients using internal useful heads, which is especially relevant for boilers with natural circulation at ultrahigh pressure.

SISTEM MAINTENANCE TRANSFORMATOR 60 MVA PADA ELECTRIC ARC FURNACE (EAF) 7 SLAB STEEL PLANT 1

<p><strong>Abstract.</strong></p><p>Preventive Maintenance is every activity undertaken to keep each component tool running in accordance with the expected conditions, through inspection, detection and prevention of total damage that is sudden (breakdown). Breakdown voltage or diode voltage drop is the minimum voltage value at the diode to be able to flow electric current. The research method used is qualitative research with a descriptive approach. In this study, the authors conducted data collection through: (1) direct observation (2) Retrieval of data using the Magger tool (3) literature study. The results of the study stated that in the examination and analysis of dissolved gas content (Dissolved gas analysis, DGA), to prevent the occurrence of: (partial) discharges, thermal failure (thermal faults), deterioration/deterioration of paper insulation/lamination. Insulation Resistance is a test to see the strength of insulation against physical and chemical damage. Damage that often occurs in the EAF 7 transformer is a breakdown voltage and an overheat transformer because the room temperature is not cold due to the transformer close to the cooking place or iron melting.</p><p> </p><p><strong>Keywords.</strong> BDV, DGA, insulation resistance, maintenance, transformer</p><p><strong> </strong></p>