As well-known, the high/medium rating rotational machines has long start-up period. So, if there is a fault in the stator winding of the machine, a propagation in the faulty point can be occurred during the long start-up period of them without activation of the protective relay. It should be noticed that the applied frequency in the stator winding is not constant during this period, while they are controlled by the static frequency converters in the motoring mode and by the turbine as the prime-mover in the generator mode.
Since the current following through the poles during the start-up is less than the rated value and the frequency is lower than the rated one, the faulty current in the shorted turns of the stator winding is low; however, the injuries can be reduced if such faulty cases have been diagnosed in the mentioned start-up moment.
Each proposed technique must be secure in the face of switching noises, unbalanced voltage sources, dynamic loading and rotor faults.
This topic is well covered in books on generator protection, the IEEE Generator Protection Guide, and in protective relays available on the market. You can look at: Protective Relaying For Power Generation Systems by D. Reimert; Synchronous Generator Protection and Control by N. Fischer and others (https://www.amazon.com/dp/0972502696?ref=myi_title_dp), or Instruction Manuals like this one (https://selinc.com/products/400G/). You can also look at my paper: https://selinc.com/api/download/102551/?lang=en
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Biology
- Biomolecules
- Nucleic Acids
- RNA