D-Q Small-Signal Admittance Modelling of Power Grid

The wideband oscillations between power electronic equipment and power grid in new power system brings new challenges to the safe and stable operation of power system. In order to study their interaction, this paper analysis the principle of PI structure transmission line model, and establish the admittance model of PI structure transmission line in the synchronous reference frame. On this basis, through numerical analysis, the equivalent small-signal admittance model of the power grid is constructed and the grid can be solved in transient stability calculation together with other parts of the system. Finally, by setting different working conditions, the correctness of the proposed model is verified in Matlab/Simulink environment.