High-voltage switches, as key equipment in power systems, their operating conditions are directly related to the safety and stability of the power grid. Timely diagnosis and scientific handling of high-voltage switch faults are important links to ensure the normal operation of the power system.
I. Analysis of the Types and Causes of High-Voltage Switch Faults
The fault manifestations of high-voltage switches are diverse and can mainly be classified into three categories: mechanical faults, electrical faults and insulation faults. Mechanical failures usually include contact wear, spring failure, transmission mechanism jamming, etc., which are often caused by long-term operation leading to component fatigue or poor lubrication. Electrical faults include phenomena such as contact ablation, increased contact resistance and abnormal arcs, which are often caused by overload, short circuit or improper operation. Insulation faults involve the aging, moisture or contamination of insulation materials, leading to partial discharge or even breakdown.
The causes of these malfunctions are diverse, such as environmental factors (humidity, temperature, dust), manufacturing defects of equipment, improper maintenance and fluctuations in operating load, etc. A deep understanding of the causes of faults is conducive to formulating targeted detection and maintenance strategies.
II. Fault Diagnosis Technology for High-Voltage Switches
Condition monitoring technology can detect abnormal signals early by real-time monitoring of the operating parameters of the switch. Common methods include current and voltage waveform analysis, contact temperature detection, and mechanical action time testing, etc. Modern intelligent devices are equipped with sensors and can continuously collect data to achieve dynamic monitoring.
2. Vibration Analysis: Mechanical faults are often accompanied by abnormal vibrations. Vibration sampling of the mechanical components of the switch is carried out by using an acceleration sensor. Abnormal frequency components are identified through spectral analysis to determine whether the mechanism is worn or loose.
3. Partial discharge detection Partial discharge caused by insulation defects is an important sign of potential hazards in high-voltage switches. By adopting ultrasonic, ultra-high frequency or electromagnetic wave detection technologies, discharge signals can be captured at an early stage to prevent insulation failure.
4. Infrared thermal imaging detects the temperature distribution on the surface of the switch through an infrared thermal imager, identifies hot spots, determines poor contact or abnormal resistance of the contacts, and assists in assessing the health status of the equipment.
5. Insulation resistance and Dielectric Loss Measurement: Regularly measure the tangent values of insulation resistance and dielectric loss angles to grasp the changing trends of insulation performance and promptly address insulation aging issues.
III. Measures for Handling Faults in High-Voltage Switches
Corresponding repair plans should be adopted for different types of faults:
Mechanical fault handling: Replace severely worn contacts and springs, clean the lubrication system, adjust the transmission mechanism to ensure flexible and smooth mechanical operation. Equipment maintenance personnel should, based on the test results, reasonably arrange the maintenance cycle to reduce the downtime caused by mechanical problems.
Electrical fault handling: For issues such as contact ablation and increased contact resistance, it is necessary to clean or replace the contacts, and at the same time, check the tightness of the circuit connection. For abnormal arc phenomena, the current protection device and operation procedures should be investigated to prevent the fault from expanding.
Insulation fault handling: For equipment with severe partial discharge, insulation materials should be replaced in a timely manner or local repairs should be carried out. Strengthen environmental control to prevent the invasion of moisture and pollutants. When necessary, vacuum drying or heat treatment techniques should be adopted to restore the insulation performance.