Transformer Cooling System

Transformer Longitudinal Differential Protection: Common Issues and SolutionsTransformer longitudinal differential protection is the most complex among all component differential protections. Misoperations occasionally occur during operation. According to 1997 statistics from the North China Power Grid for transformers rated 220 kV and above, there were 18 incorrect operations in total, of which 5 were due to longitudinal differential protection—accounting for approximately one-third. Causes of

Measure DC resistance: Use a bridge to measure the DC resistance of each high- and low-voltage winding. Check whether the resistance values among phases are balanced and consistent with the manufacturer’s original data. If phase resistance cannot be measured directly, line resistance may be measured instead. The DC resistance values can indicate whether the windings are intact, whether there are short circuits or open circuits, and whether the contact resistance of the tap changer is normal. If

The tap changer operating handle shall be equipped with a protective cover. The flange at the handle shall be well sealed with no oil leakage. Locking screws shall securely fasten both the handle and the drive mechanism, and the handle rotation shall be smooth without binding. The position indicator on the handle shall be clear, accurate, and consistent with the tap voltage regulation range of the winding. Limit stops shall be provided at both extreme positions. The insulating cylinder of the t

Overhaul Items for Transformer Conservator:1. Ordinary-Type Conservator Remove the end covers on both sides of the conservator, clean rust and oil deposits from inner and outer surfaces, then apply insulating varnish to the inner wall and paint to the outer wall; Clean components such as the dirt collector, oil level gauge, and oil plug; Check that the connecting pipe between the explosion-proof device and the conservator is unobstructed; Replace all sealing gaskets to ensure good sealing with n