A Comparative Analysis of Power System Inertia Estimation Methods

Precise online inertia estimation is essential for the stability of power system operations. It is an important tool for power system operators to control the dispatch and ancillary services accordingly. This study chose three estimation techniques from the relevant literature, which captures the different base theories that express online inertia estimation. The estimation techniques include inertia constant-based approach, acceleration time constant based procedure and kinetic energy theorem based method, each with distinct advantages and limitations. Inertia constant methods often suffer from location and size dependencies, leading to underestimations during large disturbances. The kinetic energy theorem’s accuracy is influenced by the sampling window size, which can result in over or underestimation of values. Our findings highlight the necessity for improved phasor measurement unit (PMU) measurement accuracy and advanced noise filtering techniques with the addition of increased numerical stability to capture only parameters that affect generator inertia in an extreme contingency event. Future research should aim to develop practical, measurement-based online estimation methods which express inertia in a time varying basis to enhance the precision of inertia estimation for power system operators.