Aboutcleggsan Expertise All technical areas of Electronics Engineering.
Experience BSEE, MBA, Design, R&D, University Research.
Senior Life Member of IEEE. Life Fellow of AES.
Organizations IEEE, Consumer Electronics Society, Audio Engineering Society.
Broad teaching experience; work experience mostly in consumer electronics and conversion from analog to digital technologies. Pioneer in digital audio at all levels.
1.In the protection system of generator, there is under/over frequency relay. How does this relay detects the under/over frequency? Does it has anything to do with the load demand?
2.For generator, the speed is constant. Let say 15000rpm. this is the speed of the turbine that drive the generator. When there is a demand for more power, how can the generator do it. What are the factors that can increase the generation since the speed is fix, the frequency is fix. Or how can the generator increase the power generated? If we increase the fuel, the speed that rotates the turbine hence the generator is still constant. So how can generator do it?
Answer The relay is to cut out if the frequency shifts too far away from the line it is connected to. The relay does not do this; it is controlled by the frequency sensing circuit which uses a differential frequency comparison of some kind which has a dc output which is proportional to the frequency drift. When the differential is high enough to become dangerous the dc voltage activates the relay and disconnects it from the line.
Yes, if the load is too much and slows down the generator its frequency drops out and the relay is activated.....
Your second question is related to work in and work out. You must learn more about work conservation. If you want so much work or energy out of the generator system you must put such and such work into it. To increase the generator out you must crank it harder with more torque to keep the work input equal to the amount you are drawing out of the generator.
