Experimental modal analysis is used to measure the dynamic characteristics of a structure. Traditionally, excitation is provided with either a shaker or an impulse hammer. An alternative approach is to use power electronics for powering the generator; generating a torque impulse. This torque excitation replicates much of the engine's excitation, emphasizing the vibrational modes that are assorted with the generator set's transmitted vibration. Basic system setup for modal analysis using torque impulse, comparison with conventional impulse hammer test, and illustrations of some of the flexibilities inherent in torque impact testing are included.