Law and characteristics of electrical equipment overheating and prediction methods - News - Global IC Trade Starts Here Free Join

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1. External Thermal Fault

External thermal faults in electrical equipment typically occur due to issues like poor crimping or loose connections. Under the influence of high current, these joints can heat up significantly, increasing contact resistance and creating a feedback loop that leads to further temperature rise and potential failure. These types of faults make up over 90% of all external thermal issues. Based on data collected from thousands of detected cases in recent years, it's clear that the majority of external thermal faults involve cable clamps and blade contacts, accounting for about 77% of total incidents. The average temperature increase in these areas is around 30°C, while external joints usually show a temperature rise between 20–25°C. From practical testing experience, external faults are generally categorized into three levels: minor, moderate, and severe, based on the degree of temperature rise.

2. Internal Thermal Fault

Internal thermal faults in high-voltage electrical equipment are characterized by the fault being enclosed within insulating materials or metal casings. For example, in cables, internal thermal faults often develop over a long period and tend to be relatively stable. Heat generated at the fault point spreads through the surrounding conductor or insulation, causing localized temperature increases. This makes it possible to detect such faults by monitoring the temperature of the surrounding material. Therefore, internal faults in high-voltage equipment, like cables, can be diagnosed effectively through thermal analysis.

3. Overheating Faults in Cable Sections

According to the analysis of power-related accidents, overheating in cables can lead to large-scale fires, resulting in forced shutdowns and prolonged production downtime, which causes significant economic losses. Through accident investigations, it has been found that overheated cable joints are often the direct cause of cable fires. This overheating occurs when the joint pressure is insufficient, oxidation is excessive, or the contact resistance becomes too high. Prolonged exposure to high temperatures can degrade the insulation, eventually leading to breakdown and fire occurrence.

4. Prediction Methods for Cable Overheating Faults

Based on the characteristics of cable overheating faults, an effective way to prevent overheating and subsequent fires is to monitor the temperature of cable joints regularly. By analyzing the temperature trends, the aging condition of the joint can be assessed, and early warnings can be issued before actual failure occurs. Most overheating issues occur in high-voltage cables rated at 6kV or higher. Due to the high voltage level, traditional temperature sensors may not meet safety standards. While conventional fiber optic temperature measurement systems have limitations, such as slow scanning times, the PIONEER-P fiber grating temperature measurement system offers a reliable and efficient solution for monitoring overheating in high-voltage live equipment.