Causes and Solutions for Partial Discharge in Transformers
Causes and Solutions for Partial Discharge in Transformers
Partial discharge in transformers refers to small-scale discharge phenomena within a transformer, including gas discharge and solid-state discharge. Partial discharge has a significant impact on the operational safety and stability of transformers, thus requiring timely resolution. There are several causes of partial discharge in transformers. The following are some key points: 1. Insulation Aging: Over time, transformer insulation materials will age. This aging not only leads to cracks and peeling on the surface of the insulation material but also creates gaps between the insulation and solid insulation materials, creating conditions conducive to discharge. 2. Insulation Defects: Defects may exist in the insulation material during manufacturing, such as internal gases, solid particles, and impurities. These defects can cause uneven distribution of the local electric field, forming high-field regions and triggering partial discharge. 3. Excessive Voltage Ratio: When a transformer is operating, voltage may spike instantaneously due to grid fluctuations or sudden system failures. If the voltage exceeds the transformer's withstand range, it will result in an excessively high voltage ratio, causing partial discharge. There are several methods to solve the problem of partial discharge in transformers. Here are some commonly used methods: 1. Insulation Modification: When transformer insulation is aged or severely defective, its service life can be extended by replacing insulation materials and reinforcing the insulation layer. During insulation modification, manufacturing processes should be strictly controlled to reduce the occurrence of insulation defects. 2. Insulating Oil Testing: Organic acids, moisture, gases, and solid particles in transformer oil can adversely affect its performance, leading to partial discharge. Therefore, regularly testing the insulating oil to ensure it meets requirements and promptly replacing aged or contaminated oil is an effective way to prevent partial discharge. 3. Voltage Control: By properly controlling the power supply voltage and preventing excessive voltage, the risk of partial discharge in transformers can be effectively reduced. Using voltage step-down converters and voltage stabilizers can effectively control the transformer to operate within the normal voltage range. 4. Partial Discharge Monitoring: Using professional monitoring equipment to monitor partial discharge in transformers in real time can promptly detect partial discharge phenomena and take appropriate action based on the monitoring data. Monitoring equipment typically includes partial discharge detection sensors, data acquisition devices, and monitoring systems. 5. Equipment Maintenance: Regular transformer maintenance includes cleaning the transformer surface, checking the condition of the insulation material, tightening bolts, and adjusting the air gap. Timely handling of insulation aging, insulation defects, and other faults ensures the normal operation of the transformer and reduces the occurrence of partial discharge. In summary, transformer partial discharge is caused by insulation aging, insulation defects, and excessively high voltage ratios. Solutions include insulation modification, insulating oil testing, voltage control, partial discharge monitoring, and equipment maintenance. The comprehensive application of these measures can effectively reduce the occurrence of transformer partial discharge and ensure the safe and stable operation of the transformer.
