Preliminary results on improving the modal analysis technique for voltage stability assessment

This paper investigates the theoretical foundations and practical applications of the modal analysis technique applied to power system voltage stability assessment. Improvements are made to the existing technique. The results show that two reduced Jacobian matrices, one related to reactive power and the other related to active power, are needed for extracting complete modal information. There is no need to use a full Jacobian matrix for modal analysis. As a preliminary result, a technically sound generator participation factor index is proposed based on the findings