DMD Dynamic Order Algorithm for the Estimation of Inter-area Oscillations

The paper deals with a novel version of the DMD algorithm to estimate the parameters of inter-area oscillations. In particular, the algorithm is called DMD with dynamic order, in opposition with the classical algorithm, that is known as static order DMD. The tests of static order algorithm with simulated signals have reveal some disadvantages, mainly related to the poor ability of the method to adapt to the input signal. The dynamic order allows, instead, to identify only the oscillatory modes actually present in the signal, on the basis of a preset energy threshold. The selection of the proper threshold is, therefore, a crucial stage. In the paper the assessment performed in order to select the optimal threshold is presented. Experimental tests involved both simulated signal and real frequency signals registered in a real WAMS.