(A) Critical Speed of a DC Shunt Generator and load test
Objective: To determine the critical speed of a dc shunt generator. With the fixed excitation and variable speed, as the speed reduces the OCC proportionally slides down so that the no load voltage reduces. At a particular speed, called the critical speed, the OCC is tangential to the RF line and as a result the generator fails to excite.
Preview:
With the fixed excitation and variable speed, as the speed reduces the OCC proportionally slides down so that the no load voltage reduces. At a particular speed, called the critical speed, the OCC is tangential to the Rf line and as a result the generator fails to excite.