A stability analysis system (SAS) for non-invasive estimation of damping torque associated with a power generator in an electric power network includes a processor in communication with a PMU associated with the generator. The processor is configured to receive a first data sample set from the PMU. The first data set is substantially representative of at least one measurement of the generator. The processor is also configured to determine an estimated torque of the generator based at least in part on the first data set. The processor is further configured to determine an estimated average torque and one or more estimated torque components based at least in part on the estimated torque. The processor is also configured to output the estimated average torque and the one or more estimated torque components to an operator for use in stability analysis of one or more of the generator and the network.