Coherence function estimation with a derivative constraint for power grid oscillation detection

Oscillation is one of the leading stability concerns in complex power systems. Detecting oscillations timely and accurately is vital for a power grid operator to take effective remedial reactions to stabilize the power system. This paper uses the minimum variance distortionless response (MVDR) method to estimate the magnitude squared coherence function for oscillation detection. A derivative constraint is integrated into the MVDR method, which can greatly mitigate the “blind spots” problem of the conventional MVDR method. The phenomenon of the “blind spots” and the mitigation performance of the new technique are analyzed. Simulations based on power system models are conducted to demonstrate that the new technique can effectively avoid the “blind spots” and thus increase the accuracy of oscillation detection in power systems.