What is the function of generator transverse differential protection?
2 Answers
The function of generator transverse differential protection is to protect against inter-turn short circuits in the generator stator. It is applicable when the generator neutral point has six outgoing terminals, and can also protect against asymmetric short-circuit faults inside the generator. Transverse differential protection belongs to the category of generator inter-turn short-circuit protection. Large-capacity generators generally consist of two parallel windings. Under normal conditions, the electromotive forces of the two windings are equal, each supplying half of the load current. If an inter-turn short circuit occurs in either winding, the electromotive forces of the two windings will no longer be equal. A potential difference will arise, generating circulating current between the two windings. Longitudinal differential protection serves as the primary protection for phase-to-phase short circuits inside the generator. Current transformers are installed on both the neutral point side and the generator outgoing line side, with its protection scope covering the stator windings and their outgoing lines.
The core of generator transverse differential protection is to prevent larger issues caused by internal winding short-circuit faults. As someone working in power maintenance, I often encounter such problems during equipment inspections at power plants. If there's current imbalance between two windings inside the generator, such as phase-to-phase short circuits or grounding issues, it will quickly trip and disconnect the power supply to prevent winding overheating or even burning out. This not only protects the generator itself but also prevents chain reactions that could cause grid fluctuations or power outages. In practical applications, its settings must be based on precise measurement and debugging; otherwise, unresponsive protection would be useless. I must emphasize that regular testing of protection devices is crucial because environmental humidity or equipment aging can increase failure probabilities. Overall, this protection acts like the first line of defense for generators, ensuring stable system operation - without it, power supply could be interrupted at any time.
