Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

1.Introduction1.1 Basic Function and Background of GCBThe Generator Circuit Breaker (GCB), as the critical node connecting the generator to the step-up transformer, is responsible for interrupting current under both normal and fault conditions. Unlike conventional substation circuit breakers, the GCB directly withstands the massive short-circuit current from the generator, with rated short-circuit breaking currents reaching hundreds of kiloamperes. In large generating units, the reliable operati

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

What is the Differential Protection of Transformers?Differential Protection DefinitionThe differential protection of transformer is an important relay protection method, which is used to detect the faults inside the transformer, such as winding short circuit, turn short circuit and so on. Differential protection determines whether there is a fault by comparing the difference in current on both sides of the transformer.Principle of differential protectionDifferential protection is based on a basi

What is Differential Protection?Differential Protection DefinitionDifferential protection is a method used to clear internal faults in the stator winding of a generator or alternator.Current TransformersTwo sets of current transformers (CTs) are used, one on the line side and one on the neutral side, and their characteristics must match to avoid relay malfunctions.Stabilizing ResistorA stabilizing resistor in series with the relay prevents operation due to external faults or CT saturation.Percen