Error Analysis Due to the Transient Reactance of the Generator in Simulation Verification of Power System Inertia Evaluation

Abstract

In the simulation validation process of the inertia evaluation model, it is necessary to collect the power and frequency data of a node accurately after the disturbance and use a reasonable data processing algorithm to reduce the error. Given that the power and frequency characteristics of the generator outlet side bus are similar to those of the generator, some research work selects the generator outlet side bus as the test object of the power and frequency data acquisition device. However, the generator outlet side bus inertia and the theoretical generator inertia are not equivalent because of the generator transient reactance. In this paper, we first establish a 3-machine 6-node inertia simulation model using a constant power load connected via a circuit breaker to provide system unbalanced power and then simulate the generator outlet side bus inertia under two conditions of the transient reactance set to zero and non-zero. Through comparison with the theoretical generator inertia, it is concluded that the generator outlet side bus inertia represents the theoretical generator inertia only when the transient reactance is set to zero. This conclusion applies to complex power systems as well.