Maximising rotor thermal capacity

Not only is there no uniformity in the method adopted for generator rotor overcurrent protection, but the AVR control algorithms do not directly assess the rotor's temperature. Often, after rotor overcurrent protection has functioned following a sharp increase of excitation current, 90% of the rotor's thermal capacity is still unused. A computationally reliable and fast method has been devised for assessing rotor temperature and its rate of change by monitoring each unit's rotor current and voltage. Important benefits can be gained in system operation by utilising this new method to replace existing rotor overcurrent protections.