[IEEE 2017 IEEE 58th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON) - Riga (2017.10.12-2017.10.13)] 2017 IEEE 58th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON) - The concept of synchronous machine synchronizing power normalized aggregated estimate for evaluating the machines controllers behavior during electromechanical oscillations