a novel setting-free parameter-based approach for loss of excitation protection in synchronous generators

Loss of excitation (loe) phenomenon can be hazardous for both the generator and power network stability. previously presented loe protection techniques are usually on the basis of the generator terminal impedance trajectory which have various drawbacks. therefore, this study proposes a fast and reliable setting-free loe detection method.  for this aim the derivative of various parameters of the generator including resistance ( ), reactance ( ), reactive power ( ) and flux ( ) have been utilized in order to propose three different combined indices. consequently the performance of the proposed protection algorithm has been evaluated by simulations, considering all the introduced indices in order to select the best one. the simulations have been carried out in matlab software, under different operating scenarios. the extracted results demonstrate the best performance of the last combined index, which is based on using the derivative of  ,  and . this index also shows amazing speed, accuracy, and reliability in detection of loe and discrimination of loe with stable power swing (sps), compared with the conventional impedance-based methods.