Analytical technique for synchronous generator loss-of-excitation protection

摘要

This study introduces a new analytical approach for the detection of loss of excitation (LOE) in a synchronous generator that uses only one local variable. The proposed method applies the mathematical analysis based on the generator armature current variation. In this method, after the generator loses its excitation, the second order derivative of generator armature current becomes and remains positive until a loss of synchronism event occurs. Simulations are performed for different levels of generator conditions and loads, and the results confirm the mathematical analysis. To demonstrate the suitability of the proposed method, comparisons are made with other protection methods. Studies show that the proposed strategy offers a better security and faster detection of LOE compared with the previous methods.