Power system inertia estimation method based on maximum frequency deviation

Abstract

In order to solve the problem that the inertia estimation method based on the rate of change of frequency (RoCoF) is only applicable to the centre of inertia (COI) frequency, a novel inertia estimation method is proposed based on the maximum frequency deviation. This method utilizes the property that the maximum frequency deviation of each generator is basically consistent and easy to obtain. Firstly, the inertia support power of the system is quantified according to the disturbance power and frequency, and then the inertia support energy of the disturbance process is obtained. Finally, the system inertia is estimated by the ratio of the inertia support energy to the maximum frequency deviation. The proposed estimation method is suitable for non-COI frequency, which makes it unnecessary to obtain the COI frequency and RoCoF. On this basis, a simplified estimation method is proposed based on the linearization of regulation power, which improves the estimation accuracy and simplifies the estimation process. According to the proposed method, the governor test data is used to estimate, which increases the estimation times and provides more information for system stable operation. The effectiveness and accuracy of the proposed method are validated by some cases.