Generators' inertia assessment by state estimation

Abstract

Abstract This paper merges two well-known strategies to estimate the inertia of synchronous generators in operation: (i) the extended Kalman filter (EKF) state estimation is used to estimate state variables. On the other hand, (ii) a novel and accurate method is used to calculate the rate-of-change of frequency (RoCoF) from the estimated angular velocity or position. The primary assumption lies in the fact that it is assumed that it is possible to have the measurement of the frequency or angular velocity in the machine under study. Furthermore, calculations become more precise using the RoCoF than the derivatives calculated in the transient stability algorithm, mainly under the integration step utilised there. Thus, an accurate inertia estimation is achieved by combining these two tools. Results are presented for the 16-generator system.